Construction Dictionary 15 - Mechanical

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SECTION 15046

ACCEPTANCE TEST: An investigation performed
on an individual lot of a previously quali—
fled product, by, or under the observa—
tion of, the purcha ser to establish con—
formity with a purchase agreement.
(PPI)
ACETE PLASTICS: Plastics based on resins
having a predominance of acetal linkages
in main chain.
(PPI)
ACRYLONITRILE-BUTADIENE-STYRENE (ABS) PIPE
AND PITTING PLASTICS: Plastics contain-
ing polymers and/or blends of polymers,
in Which the minimum butadiene content
is 6 percent, the minimum acrylonitrile
content is 15 percent, the minimum sty—
rene and/or substituted styrene content
is 15 percent, and the maximum content
of all other monomers is not more than 5
percent, and lubricants, stabilizers and
colorants.
(PPI)
ADHESIVE: A substance capable of holding
materials together by surface attachment.
(PPI)
ADHESIVE, SOLVENT: An adhesive having a
volatile organic liquid as a vehicle.
See "Solvent Cement" .
(PPI )
(1) The effect on materials of ex—
AGING :
posure to an environment for an interval
of time. (2) The process of exposing
materials to an environment for an interval
of time.
(PPI)
ANT I—OXIDANT : A compounding ingredient add—
ed to a plastic composition to retard possi—
ble degradation from contact with oxygen
(air) particularly in processing at or
exposures to high temperatures.
(PPI )
ARTIFICIAL WEATHERING: The exposure of plas-
tics to cyclic laboratory conditions in—
volving changes in temperature, relative
humidity, and ultraviolet radiant energy,
with or without direct water spray, in an
attanpt to produce changes in the materi—
al similar to those observed after long—
tern continuous outdoor exposure.
(PPI)
Note: The laboratory exposure conditions
are usually intensified beyond those en—
countered in actual outdoor exposure in an
attempt to achieve an accelerated effect.
This definition does not involve exposure
to special conditions such as ozone, salt
spray, industrial gases, etc.
(PPI)
BELL END: The enlarged portion Of a pipe
that resembles the socket portion of a
fitting and that is intended to be used
to make a joint by inserting a piece of
pipe into it. Joining may be accomplish—
ed by solvent cements, adhesives, or
mechanical techniques.
(PPI)
BE*M LOADING: The application of a load to
a pipe between points of support ,
usually expressed in pounds and the dis—
Cance between the centers of the supports.
(PPI)
15046
BURST STENGTH:
PLASTIC PIPE
The internal pressure
quired to break a pipe or f This
pressure will vary with the rate of build—
up of the pressure and the time during
which the pressure is held.
(PPI)
BUTYLENE. PLASTICS:
Plastics based on resins
rlEde by the polymerization Of butene or
copolymerization of butene with one or more
tmsaturated compounds, the butene being in
greatest arnount by weight.
(PPI)
CELLULOSE ACETATE BUTYRATE PLASTICS:
Plastic
txzde by compounding a cellulose acetate—
butyrate ester with plasticizers and other
ingred ients.
cellulose acetate butyrate
ester is a derivative of cellulose (obtain—
from cotton and/or pulp) made by
converting some of the hydroxyl groups in
cellulose to acetate and butyrate groups
with chemicals.
(PPI)
CEMENT: See adhesive and solvents, cement.
(PPI)
(1) The effect of
CHEMICAL RESISTANCE:
specific chemicals on the properties of
plastic piping with respeee to concenera—
tion, temperature and time of exposure.
(2) The ability of a specific plastic pipe
to render service for a useful period in
the transport of a specific chemical at a
specified concentration and temperature.
(PPI)
COLD FLOW: see "Creep"
(PPI)
COMPOUND: The intimate admixture of a polymer
or polymers with other ingredients such as
fillers, softeners, plasticizers, catalysts,
pigments, dyes, curing agents, stabilizers,
anti—oxidants, etc.
(PPI)
COPOLYMER: see "Polymer"
(PPI)
CuEP : The time—dependent part of strain re—
suiting from stress, that is, the dimension—
al change caused by the application of load
over and above the elastic deformation and
with respect to time.
(PPI)
CtJRE : To change the properties of a polymeric
system into a final, more stable, usable
condition by the use Of heat, radiation,
or reaction with chemical additives.
(PPI)
DEFLECTION TEMPERATURE:
The temperature at
which a specimen will deflect a given dis—
tance at a given load under prescribed con—
ditions of test.
See ASTM D648. Formerly
called heat di stortion.
(PPI)
DEGRADATION: A deleterious change in the
chemical structure of a plastic.
see also
"deter ioration " .
(PPI)
DETERIORATION: A permanent change in the phy-
sical properties of a plastic evidenced by
of these properties.
(PPI)

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SECTION 15046
DIFFUSION: The movænent of a material, such as
If
a gas or liquid, in the body of a plastic.
the gas or liquid is absorbed on one side of a
piece of plastic and given off on the other
side, the phenomenon is called permeability.
DS ffusion and permeability are not due to holes
or pores in the plastic but are caused and con—
(PPI)
trolled by chemical mechanisms.
DIMENSION RATIO: The diameter of a pipe divided
by the wall thickness. Each pipe can have
dimension ratios depending on whether the out—
side or inside diameter is used. In practice,
the outside diameter is used if the standard
requirement and manufacturing control are
based on this diameter. The inside diameter is
used when this measurement is the controlling
(PPI)
one.
DRY—BLEND : A free—flowing dry compound prepared
without fluxing or addition of solvent. (PPI)
ELASTICITY: That property of plastics materials
by virtue of which they tend to recover their
original size and shape after deformation.
(PPI)
If the strain is proportional to the
Note :
applied stress, the material is said to exhibit
(PPI)
Hookean or ideal elasticity.
ELASTOMER: A Nterial which at room temperature
can be stretched repeatedly to at least twice
its original length and, upon immediate re—
lease of the stress, will return with force to
its approximate original length. (PPI)
ELEVATED TEMPERATURE TESTING: Tests on plastic
(PPI)
pipe above 23C (73F)
ENVIRONMENTAL STRESS CRACKING: cracks that de-
velop when the material is subjected to stress
in the presence of specific chemicals. (PPI)
Plastics based on resins
ETHYLENE. PLASTICS.
made by the polymerization of ethylene or co—
polymeriza Of ethylene with one or
other unsaturated compounds, the ethylene being
(PPI)
in greatest amount by weight.
EXTRUSION: A method whereby heated or unheated
plastic forced through a shaping orifice be—
(PPI)
comes one continuously formed piece.
FAILURE, ADESIVE: Rupture of an adhesive bond,
such that the plane Of separation appears to
(PPI)
be at the adhesive—adherend interface.
FIBER STRESS: The unit stress, usually in pounds
per square inch (psi) , in a piece of material
that is subjected to an external load. (PPI)
FILLER: A relatively inert material added to a
plastic to its strength, permanence,
working properties, or other q.zaiities, or to
See algo "Reinforced Plastic 't
lower costs.
(PPI )
FORMING: A in which the shape of plastic
pieces such as sheets, rods or tubes is changed
to a desired configuration. See also "Thermo—
(PPI )
forming n
15046
PLASTIC PIPE
Note; The use of the term "forming" In
plastics technology does not include
such operations as molding, casting or
extrusion, in which shapes or pieces
are made from molding materials or
(PPI)
liquids.
FUNGI RESISTANCE: The ability of plastic
pipe to withstand fungi growth and/or
their metabolic products under normal
conditions of service or laboratory
tests simulating such conditions. (PPI)
EAT DISTORTION: see "Deflection tempera-
(PPI)
ture "
(PPI)
I-EAT FORMING: see "Thermoforming" .
JOINING: Making a pipe joint by
heating the edges of the parts to be
joined so that they fuse and become es—
sentially one piece with or without the
addi tion of additional material. (PPI)
HOOP STRESS: The tensile stress, usually
in pounds per sguare inch (psi) , in the
circumferential orientation in the wall
of the pipe when the pipe contains a
gas or liquid under pressure. (PPI)
HYDROSTATIC DESIGN STRESS: The estimated
rrzximum tensile stress in the wall of
the pipe in the circumferential orien—
tation due to internal hydrostatic pres—
sure that can be applied continuously
with a high degree Of certainty that
failure of the pipe will not occur. (PPI)
The hoop
HYDROSTATIC STRENGTH (QUICK) :
stress calculated by means of the ISO
equa tion at which the pipe breaks due to
an internal pressure build—up, usually
(PPI)
within 60 to 90 seconds.
LONG-TERM BURST: The internal pressure at
which a pipe or fitting will break due
to a constant internal pressure held
(PPI)
for 100,000 hours (11.43 years).
IMPACT r IZOD: A specific type of impact
test made with a pendulum type machine.
The specimens are ælded or extruded
with a machined notch in the center. see
(PPI)
ASTM D256.
IMPACT, TUP: A falling weight (tvp) impact
test developed specifically for pipe and
There are several variables
fittings.
that can be selected. See ASTM D 2444.
(PPI )
ISO EQUATION: An equation showing the
interrelations between stress, pressure
and dimensions in pipe, namely :
S = P(ID + t) or P(OD - t)
where S
stress
pressure
average inside diameter
average outside diameter
minimum wali thickness . (PPI)

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SECTION 15046
Ref er ence :
ISO R161-1960 Pipes of Plas-
tics Materials for the Transport of
Fluids (Outside Diameters and Nominal
Pressures) part I, Metric series. (PPI)
JOINT: The location at which two pieces of
pipe or a pipe and a fitting are connected
The joint may be made by an ad—
together .
hesive, a solvent—cement or a mechanical
device such as threads or a ring seal. (PPI)
LONG-TEN*I HYDROSTATIC STRENGTH; The esti-
mated tensile stress in the wall of the
pipe in the circumferential orientation
(hoop stress) that when applied continu—
ously cause failure of the pipe at
100, 000 hours (11.43 years). These
strengths are usually obtained by extrap—
olation of log—log regression equations
or plots.
(PPI)
MOLDING, COMPRESSION: A method of forming
objects from plastics by placing the ma—
terial in a confining mold cavity and ap—
plying pressure and usually heat.
(PPI)
MOLDING, INJECTION: A method of forming
plastic objects from granular or pos•dered
plastics by the fusing of plastic im a
chamber with heat and pressure and then
forcing part of the rnass into a cooler
chamber where it solidifies.
(PPI )
Note : This method is commonly used to
form obj ects from thermoplastics. (PPI)
MONOMER: A relatively simple chemical which
can react to form a polymer. See also
" Polymer t'
(PPI)
Plastics based on resins
NYLON PLASTICS:
composed princ ipaIIy of a long—chain syn—
thetic polymeric amide which has recurring
amide groups as an integral part of the
main polymer cha*m.
(PPI)
Pla stics based on resins
OLEFIN PLASTICS:
made by the polymerization of olefins or
copolymerization of olefins with other un—
saturated compounds, the olefins being in
greatest amount by weight.
Polyethylene ,
polypropylene and polybutyl ene are the most
cormon olefin plastics encountered in
pipe. (PPI)
OUTDOOR EXPOSURE: Plastic pipe placed in ser-
vice or stored so that it is not protected
from the elements of normal 'eather condi—
tions, i.e., the sun's rays, rain, air and
wind. Exposure to industrial and wa ste
gases, chemicals, engine exhausts, etc. ,
are not considered normal "outdoor expo—
sure.
(PPI)
PERMANENCE: The property of a plastic which
describes its resi stance to appreciable
changes in characteristics with time and
env ironm en t.
PERMEABILITY:
(PPI)
See "Diffusion".
PLASTIC PIPE
PLASTIC: A material that contains as aq es-
sential ingredient an organic substance of
large molecular weight, is solid in its
finished state, and, at some stage in its
11Enufactuze or in its processing into
finished articles, can be shaped by flow.
(PPI )
The adjective plastic indicates that the
noun modified is made of, consists Of, or
pertains to plastic.
Note (1) : The above definition may be used
as a separate meaning to the definitions
contained in the dictionary for the adjec—
tive "plastic"
(PPI)
Note (2): The plural form may be used to
refer to two or more plastic materials, for
example, plastics industry. However, when
the intent is to distinguish "plastic prod—
uctsn from "wod products" or "glass prod—
ucts "
the singular form should be used.
As a general rule, if the adjective is to
restrict the noun modified, with respect
to type of material, t' plastic n should be
used; if the adhective is to indicate that
more than one type of plastic material is
or may be involved, "plastics is permissi—
ble.
(PPI)
PLASTICIZER: A rnaterial incorporated in a
plastic to increase its wrkability and its
flexibility or distensibility.
The addition of the plasticizer rnay
Note :
lower the melt viscosity, the temperature of
the second—order transition, or the elastic
modulus of the plastic.
(PPI)
PLASTICS CONDUIT:
Plastic pipe or tubing used
as an enclosure for electrical wiring.
(PPI)
PLASTICS PIPE: A hollow cylinder of a plas-
tic material in Which the wall thicknesses
are usually small when compared to the dia—
meter and in which the inside and outside
walls are essentially concentric.
plastics tubing.
(PPI)
PLASTICS TUBING: A particular size of plas-
tics pipe in which the outside diameter is
essentially the same as that of copper
tubing.
See "plastics pipe " .
(PPI)
POLYBUTYLENE: A polymer prepared by the
polymerization of butene—l as the. sole
See "Polybutyl ene Plastics" and
ronomer.
"Eutylene Plastics. "
(PPI)
POLYBUTYLENE PLASTICS: Plastics based on poly-
mers made with butene—l as essentially the
sole monomer .
(PPI)
POLYETHYLENE: A polymer prepared by the poly-
merization of ethylene as the sole monomer.
See "Polyethylene Plastics" and "Ethylene
Plastics.
(PPI)
POLYETHYLENE PLASTICS :
Plastics based on
polymers made with ethylene as essentially
the so Ie monomer. Note:
In common usage
(PPI)
15046

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SECTION 15046
fov this plastic, essentially means no less than
ethylene and no less than 95% total olefins.
(PPI)
POLYiviER : A compound formed by the reaction of
simple molecules having functional groups that
permit their combination to proceed to high
molecular weights under suitable conditions .
Polymers may be formed by polymerization (addi—
tion polymer) or polycondensation (condensa—
tion polymer ) . When two or more monomers are
involved, the product is called a copolymer.
(PPI)
POLYMERIZATION: A chenical reaction in which
the molecules of a monomer are linked together
to form large molecules whose molecular weight
is a multiple Ot that Of the original sub—
stance. When two or more monomers are involv—
ed, the process is called copolymerization or
(PPI)
heteropolymer ization.
POLYOLEFIN: A polymer prepared by the polymeri—
zation of an olefin (s) as the sole monomer (s) .
See " polyolefin plastics" and "Olefin plas—
(PPI)
tics.
POLYOLEFIN PLASTICS: Plastics based on polymers
made with an olefin (s) as essentially the sole
(PPI)
monomer (s) .
POLYPROPYLENE; A polymer prepared by the poly—
mer ization of propylene as the sole monomer .
See "Polypropylene plastics" and "Propylene
(PPI)
plastics l' •
POLYPROPYLENE PLASTICS: Plastics based on poly-
mers made with propylene as essentially the
(PPI)
sole monomer.
POLYSTYRENE: A plastic based on a resin made
by polymerization of styrene as the sole mono—
(PPI)
See "Styrene plastics" .
mer .
Polystyrene may contain minor propor—
Note:
tions of lubricants, stabilizers, fillers ,
(PPI)
pigments and dyes.
POLY (VINYL CHLORIDE): A resin prepared by the
polymerization of vinyl chloride with or with—
out the addition Of small amounts Of other
(PPI)
monomer s.
PLastics made
POLY (VINYL CHLORIDE) PLASTICS:
by combining po.ly (vinyl chloride) with
colorants, fillers, plasticizers, stabilizers ,
lubricants, other polymers and other compound—
ing ingredients. Not all of these modifiers
(PPI)
are used in pipe compounds.
(PPI )
POWDER BLEND: see "Dry-Blend".
PRESSURE: When expressed with reference to
pipe the force per unit area exerted by the
(PPI)
medium iti the pipe.
PRESSURE RATING: The estimated maximum pres—
sure that the medium in the pipe can exert
continuously with a high degree of certainty
that failure of the pipe will not occur. (PPI)
15046
PLASTIC PIPE
Plastics based on
PROPYLENE PLASTICS:
resins made by the polymerization of
propylene or copolymerization of pro—
pylene with one or more other unsat"rat—
ed compounds, the being in
(PPI)
greatest amount by weight.
QUALIFICATInN TEST: An investigation, in-
dependent of a procurement action, per—
formed on a oroduct to determine whether
or not the *oduct conforms to all re—
quirements of the applicable specifica—
(PPI)
tion.
Note: The examination is usually con—
ducted by the agency responsible for the
specification, the purchaser, or by a
facility approved by the purchaser, at
the request of the supplier seeking in—
clusion of his product on a qualified
(PPI)
products list.
QUICK BURST: The internal pressure requi red
to burst a pipe or fitting due to an
internal pressure build—up, usually with—
(PPI)
in 60 to 90 seconds.
REINFORCED PLASTIC: A plastic with some
strength properties greatly superior to
those of the base resin, resulting from
the presence of high strength fillers
znbedded in the composition. See also
(PPI)
"F i i ler "
RESIN: A solid, semisolid or pseudosolid
organic material which has an indefinite
and often high molecular weight, exhibits
a tendency to flow when subjected to stress ,
usually has a softening or melting range ,
and usually fractures conchoidally. (PPI)
REWORKED MATERIAL (THEPNOPLASTIC) : A plas-
tic material that has been reprocessed,
after having been previously processed
by molding, extrusion, etc., in a fab—
ricator•s plant. (PPI)
RUBBER: A material that is capable of re—
covering from large deformations quickly
(PPI)
and forcibly. See "Elastomer"
SN4PLE : A small part or portion of a
plastic material or product intended
to be representative of the whole. (PPI)
SARAN PLASTICS; Plastics based on resins
made by the polymerization of vinylidene
chloride or copolymerization of vinyli—
dene chlor ide with other unsaturated
compounds , the vinylidene chloride be—
ing in greatest amount of weight. (PPI)
SCHEDULE: A pipe size system (outside
diameters and wall thicknesses) origin—
ated by the iron pipe industry.
SELF-EXTINGUISEIING: The ability of a plas-
tic to ±esist burning when the source of
heat or flame that ignited it is removed.
(PPI)

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SECT$ON 15046
. SERVICE FACTOR: A factor which is used to
reduce a strength value to obtain an
engineering design stress. The factor
may vary depending on the service cond i—
tions, the hazard, the length of service
desired and the properties of the pipe.
(PPI)
SET: TO convert an adhesive into a fixed
or hardened state by chemical or physi—
cal action, such as condensa tion, poly—
merization, oxidation, vulcanization,
gela tion, hydration, or evaporation
of volatile constituents.
See also "Cüren
(PPI)
SOFTENING RANGE: The range of temperature
in which. a plastic changes from a rigid
to a soft state.
(PPI)
Note: Actual values will depend on the
method of test.
Sometimes referred to
as softening point.
(PPI)
SOLVENT CEMENT; In the plastic piping field,
a solvent adhesive that contains a solvent
that dissolves or softens the surfaces
being bonded so that the bonded assembly
becomes essentially one piece of the same
5.
4.
6.3
7.3
5.3
9.
12.5
13.5
11.5
31.5
32.5
30.5
type of plastic.
SOLVENT CEMENTING:
a solvent cement.
(PPI)
(PPI)
Making a pipe joint with
See "Solvent cement"
SPECIMEN : An individual piece or portion Of
a sample used to make a specific test.
specific tests usually require specimens
of specific shape and dimensions. (PPI)
STABILIZER: A compound ing ingredient added
to a plastic composition to retard possi—
ble degradation on exposure to high tern—
peratures, particularly in processing. An
anti —oxidant is a specific kind of stabi—
lizer. (PPI)
STANDARD DIMENSION RATIO; A selected series
of numbers in which the dimensions ratios
are constants for ail sizes of pipe for
each standard dimension ratio and which
are the USÄSI Preferred Nunber Series 10
modified by +1 or —I.
If the outside dia—
meter (OD) is used, the modifier is +1.
If the inside diameter (ID) is used, the modi—
fier is —1. Some of the numbers are as
follows :
USÄSI Preferred
Number Series 10
8.
10.
16.
20.
25.
40.
50.
63.
OD Control
6.
11.
17.
21.
26.
41.
51.
64.
P T AS TTC.
Reference: USASI Preferred Numbers, 417.1—
1958, UDS 389.17.
(PPI)
STANDARD THERMOPLASTIC PIPE MATERIALS DESIGNA-
TION CODE: A means for easily identifying a
thermoplastic pipe material by means of
three elements. The first element is the
abbreviation for the chemical type of the
plastic in accordance with ASTM D1600. The
second is the type and grade (based on prop—
erties in accordance with the ASTM materials
specification) ; in the case of ASTM specifica—
tions which have no types and grades or
those in the cell structure system, two digit
numbers are assigned by the PPI that are used
in place of the larger numbers. The third
is the recommended hydrostatic design stress
(REDS) for water at 23C (73F) in pounds per
square inch divided by 100 and with decimals
dropped, e.g. , PVC 1120 indicates that the
plastic is poly (vinyl chloride) , Type I,
Grade according to ASTM D1784 with a
REDS of 2000 psi for water at 73?. PE 3306
indicates that the plastic is polyethylene
Type 111 Grade 3 according to ASTM D1248
with a NIDS of 630 psi for water at 73F.
PP 1208 is polypropylene, Class 1—19509 in
accordance with ASTM D2i46 with a RHDS of
800 psi for water at 73F; the designation
Of PP12 for polypropylene class 1—19509 will
be covered in the ASTM and Product Standards
for polypropylene pipe when they are issued.
(PPI)
STIFFNESS FACTOR: A physical property of
plastic pipe that indicates the degree of
flexibility of the pipe when subjected to
external loads.
see ASTM D2412.
(PPI)
STRAIN: The ratio of the amount of deformation
to the length being deformed caused by the
application Of a load on a piece of materi—
(PPI )
STRENGTH: The stress required to break, rup—
ture or cause a failure.
(PPI)
STRESS: When expressed with reference to
pipe, the force per unit area in the wall
of the pipe in the circumferential orientatior.
due to internal hydrostatic pressure. (PPI)
STRESS—CRACK: External or internal cracks in a
plastic caused by tensile stresses less than
that of its short-time mechanical strength.
(PPI)
Note: The development of such cracks is
frequently accelerated by the environment
to which the plastic is exposed. The
stresses which cause cracking may be pres—
ent internally or externally or may be
combinations of these stresses. The ap—
pearance of a network Of fine cracks is
called crazing. (PPI)
ID Control
7.
9.
15.
19.
24.
39.
49.
62 .
15046

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PLASTIC PIPE
SECTION 15046
STRESS RELAXATION: The decrease of stress with
respect to time in a piece of plastic that
(PPI)
is subject to an external load.
STYRENE PLASTICS: Plastics based on resins
made by the polymerization of styrene or co—
polymerization of styrene with other unsat—
urated compounds, the styrene being in great—
(PPI)
est amount by weight.
STYRENE-RUBBER PLASTICS: compositions based on
rubbers and styrene plastics, the styrene plas—
tics being in greatest amount by weight. (PPI)
STYRENE-RUBBER (SR) PIPE AND FITTING PLASTICS:
Plastics containing at least 50 percent sty—
rene plastics combined with rubbers and other
compounding materials, but not more than 15
(PPI )
percent acrylonitrile.
SUSTAINED PRESSURE TEST: A constant internal
pressure test for 1000 hours. (PPI)
THERMOFORMING: Forming with the aid of heat.
(PPI)
See also "Forming"
THERMOPLASTIC: A plastic which is thermoplas-
(PPI)
tic in behavior.
Capable of being repeatedly softened by in—
crease of temperature and hardened by decrease
(PPI)
of temperature.
Note; Thermoplastic applies to those materi—
als whose change upon heating is substantially
(PPI)
phys ical.
THERMOSET: A plastic which, when cured by ap—
plication of heat or chemical means, changes
into a substantially infusible and insoluble
(PPI)
product.
Pertaining to the state Of a resin in which
it is relatively infusible. (PPI)
THERMOSETTING: capable of being changed into a
substantially infusible or insoluble product
when cured under application of heat or chemi—
(PPI)
cal means.
VINYL CHLORIDE PLASTICS; Plastics based on resins
made by the polymerization Of vinyl chloride
or copolymerization of vinyl Chloride with
other unsaturated compounds, the vinyl chloride
(PPI)
being in greatest amount by we ight.
VIRGIN 2•mTERIAL: A plastic material in the form of
pellets, granules, powder, floc or liguid that
has not been subjected to use or processing other
than that required for its original manufacture.
(PPI)
WELD—or nilT-LINE: A mark on a molded plastic
formed by the union of two or more streams of
plastic flowing together. (PPI)
15046

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SECTION 15050
(Plumbing, Heating ,
ABSORBENT: A mterial which, due to an af—
finity for certain substances, extracts
one or more such substances from a liquid
or gaseous medium with which it contacts
and which changes physically or chemically,
or both, during the process Calcium chlor—
ide is an example of a solid absorbent,
while solutions of lithium chloride, li—
thium bromide and ethylene glycols are Ii—
quid absorbents .
ABSORPTION : A process whereby a material
extracts one or more substances present in
an atmosphere or mixture of gases or Ii—
quids accompanied by the material ' s phy—
sical and/or chemical changes.
ACCELERATION DUE TO GRAVITY: The rate of
increase in velocity of a body falling
freely in a vacuum. Its value varies with
latitude and elevation. The International
Standard taken at sea level and 45 degrees
latitude is 980.665 cm/s(32.174 f t/ s) .
ACCUMULATOR: A storage chamber for low—side
liquid refrigerant, also known as " surge
drum" or "surge header " ;
also, a pressure
vessel whose volume is used in a refriger—
ant circuit to reduce pulsa tion, also a
pressure vessel connected to more than one
circuit Of a pneumatic systern to obtain the
average pressure of the connected circuits.
ACTIVATED ALUMINA: A form of al uminum oxide
which adsorbs moi sture readily and is used
as a drying agent.
ACTIVATED CARBON: A form of carbon made por—
ous by special treatment by which it is cap—
able of adsorbing various odors, anesthetics
and Other vapors.
ADIABATIC PROCESS: A thermodynamic process
dur ing which no heat is extracted from or
added to the system.
ADSORBENT: A material which has the ability
to cause molecules of gases, liquids or
solids to adhere to its internal surfaces
without chang ing the adsorbent physically
or chemically. Certain so lid materials,
such as silica gel and activated alumina ,
have this property.
ADSORPTION : The action, as sociated with the
surface adherence, of a material in extract—
ing one or more substances present in an at—
mosphere or mixture of gases and liquids ,
unaccompanied by physical or chemical change.
AERATION : Exposing a substance or area to
air circu
AEROSOL; An assemblage of srnaII particles,
solid or liquid, su spended in air. The dia—
meters of particles may vary from 100 microns
to 0.01 micron or less, e.g., dust, fog,
smoke.
15050
BASIC MATERIALS AND METHODS
Refrigerating, Ventilating and Air Conditioning)
AGITATOR: A device causing turbulent motion
in a fluid confined in a tank.
AIR, AMBIENT: Generally, the air surrounding
an object.
AIR, OUTSIDE: External air; atmosphere ex—
ter ior to refrigerated or conditioned space;
ambient (surrounding) air.
AIR, RECIRCULATED; Return air passed through
the conditioner before being resupplied to
the conditioned space.
AIR, REHEATING OF:
In an air conditi oning
system, the final step in treatment in the
event the temperature is too low.
AIR, RETURN: See "air recirculated .
AIR, SATURATED: Moist air in which the partial
pressure of water vapor equals the vapor pres—
sure of water at the existing temperature.
This occurs when dry air and saturated water
vapor coexist at the same dry—bulb temperature.
AIR, SECONDARY : Air for combustion supplied to
the furnace to supplement the primary air.
AIR, STANDARD: Dry air at a pressure of 760 mm
(29.92 in.) Hg at 21 degrees centigrade (69.8
degrees Fahrenheit) temperature and with a
specific volume of O. 833 m 3/ kg (13.33 ft3/Ib) .
AIR BLAST: Forced air circulation.
AIR CHANGE: Introducing new, cleansed, or re—
circulated air to conditioned space, measured
by the number of complete changes per unit
time.
AIR CHANGES : A method of expressing the ænount
of air leakage into or out of a building or
room in terms of the number of building vol—
umes or room volumes exchanged .
AIR CLEANER: A device used to remove airborne
impur ities .
AIR CONDITIONER, ROOM; A factory-made, encased
assembly designed as a unit primarily to pro—
vide free delivery of conditioned air to an
enclosed space, room, or zone .
It includes
a prime source of refrigeration for cooling
and dehumidification and means for circulat—
ing and cleaning air; also means for ventilat—
ing and heating .
AIR CONDITIONING, COMFORT: The process of treat-
ing air to control simultaneously its tempera—
ture, humidity, cleanliness and distr ibution
to meet the comfort requirements of the occu—
pants of the conditioned space .
AIR CONDITIONING, INDUSTRIAL: Air conditioning
for uses other than comf or t.

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SECTION 15050
AIR CPNDITIONING, SUMPER: Comfort air conditioning
used pr imarily when outside tanperature and hu—
midity are above those to be maintained in the
conditioned space.
AIR CONDITIONING, WINTER: Heating, humidifica-
tion, air distribution, and air cleaning, where
outside temperature is below inside room tern—
per ature.
AIR-CONDITIONING UNIT: An assembly of equipment
for the air treatment to control simultaneously
its tanperature, humidity, cleanliness, and
distribution to meet the requirements of a
conå itioned space.
AIR-CONDITIONING UNIT, COOLING (HEATING): A
specific air —treating combination, consisting
of means for venti lation, air circulation, air
cleaning and heat transfer, with control
means for cooling (or heating) .
AIR-CONDITIONING (COOLING) UNIT, SELF-CONTAINED:
An air—conditioning unit having the means for
ventilation, air circulation, air cleaning,
and air cooling, and the controls thereof ,
in the same cabinet with the condensing unit.
Self—con tained air —conditioning units are
(1) re—
classified by the following methods:
j ecting condenser heat (water—cooled and evap—
(2) introducing ventilation
oratively cooled) ;
air (no ventilation, ventilation by drawing
air from outside, ventilation by a combination
of the two methods); and (3) discharging air
to the room (free delivery or pressure type) .
AIR COOLER : factory—encased assembly of ele—
ments whereby the temperature of air passing
through the device is reduced.
AIR COOLER, DRY: Removes sensible heat from
the dehydrated air , whenever it leaves the
dehydrator at an elevated tanperature.
AIR COOLER, DRY-TYPE: A forced circulation air
cooler wherein heat transfer is not implement—
ed by a liquid spray whj.le in operation
AIR COOLER, FORCED CIRCULATION: A cooler in-
cluding a fan or a blower for positive aiY
circulation.
AIR COOLER, FREE DELIVERY: A cooler taking air
from and discharging it directly to the spaée
to be treated without an element external to
the cooler to impose air resistance. e
AIR COOLER, NATURAL CONVECTION: An air cooler
depending on natural convection for air cir—
cu Ia t ion.
AIR COOLER, PRESSURE-TYPE: A cooler for use with
one or more external elements which impose air
resista nce.
AIR TUNNEL: A refrigerated tunnel with rapid air
circulation through which the product to be
frozen is passed.
AIR WASHER: A spray system or device for
cleaning, humidifying or dehumidifying the
air .
15050
BASIC MATERIALS AND METHODS
ALGAE; A minute fresh wa ter plant growth
which forms a scum on the surfaces of re—
circulated water apparatus, interfering
with fluid flow and heat transfer.
ANALYZER: A device in the high side of an
absorption system for increasing concen—
tration of refrigerant in the vapor en—
tering the rectifier or condenser .
ANEMOMETER: An instrument for mea sur ing
the velocity of a fluid.
ANTICIPATING CONTROL: one which, by arti-
ficial means, is actuated sooner than it
muld be without such means to produce a
differential of the controlled
pr operty.
In an evaporative cooling device ,
APPROACH :
the difference between the average tem—
perature of the circulating water leav—
ing the device and the average wet-bulb
ta-nperature of the entering air .
In a
conduction heat exchanger device, the
temperature difference between the leav—
ing treated fluid and the entering work—
ing fluid.
AREA, CORE: The total plane area of the
portion of a grille, face or register
bounded by a line tangent to the outer
edges of the outer openings through
which air can pass.
AREA, FREE: The total minimum opening
area in an air inlet or outlet through
which air can pass.
ASPECT RATIO: In air distribution outlets,
the ratio of the length of the core of
a grille, face or register to width.
In recta ngular ducts, the ratio of width
to depth.
ASPIRATION : Production of movement in a
fluid by suction created by fluid
vel ocity.
ATOMIZE: Reduce to fine spray.
BAFFLE : A surface used for deflecting
fluids, usually in the form of a plate
or wall.
term applied to the hydro—
BALLING :
metric scale used in measuring the
This scale provides
strength of worts.
directly the amount of extract dissolved
in the wort as the weight percentage of
sugar in water.
BAROMETER: Instrument: for measuring a t—
spheric pressure.
BELT DRIVEN: Driver and dr iven, as motor
and compressor, equipped with suitable
sheaves or pulleys and connected by one
or more belts to operate at a speed
ratio establ {shed by the relative dia—
meters of the pulley.

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SECTION 15050
>IMETALLIC ELEMENT: An elanent formed of
metals having dif ferent coefficients of
thermal expansion, used as a temperature
control device.
BLAST HEATER: A set of heat transfer coils
or sections used to heat air which is
drawn or forced through .i.t by a fan.
BLEEDER: Pipe attached, as to a condenser,
to bleed off liquid refrigerant parallel
to main flow.
BLOVER: A fan used to force air under pres—
sure .
BOILER: A Closed vessel In which a liquid
Is heated or vaporized.
BOILER, FIRETUBE: A boiler with straight
tubes, which are surrounded by water and
stearn and through which 'the combusted
products pass.
BOILER, PACKAGED: A boiler equipped and
shipped complete with fuel burning equip—
ment, mechanical draft equipment, auto—
mat ic controls and accessories. Usually
shipped in one or more major sections .
BOILER, WATERTUBE: A boiler in which the
tubes contain v.ater and steam, the heat
being applied to the outside surface.
BOILING POINT: The tanperature at which
the vapor pressure of a liquid equals the
absolute external pressure at the liquid—
vapor interface.
BORE: Inside diameter of a cylinder.
BRAZED: Jointed by fusion using a spelter
on the order of brass; considered equiva—
lent to hard soldering .
BREAKER STRIP , REFRIGERATOR CABINET: A
separate insulating element or integral
insulating extension of the cabinet in—
ter ior surfaces around the per iphery of the
cabinet door or drawer opening (s) , which
functions as a thermal barrier to minimize
heat flow to the cabinet interior .
BREATHER PLUG: A removable plug, cap or
other means of venting a space containing
Insulating material through vaportight
sheathing to the interior of a refrigerat—
ed compartment .
BRINE: Any liquid cooled by the refrigerant
and used for the heat transmission without
a change in its state, having no flash
point or a flash point above 65.6 degrees
Centigrade (150 degrees Fahrenheit) .
BRINE, ELECTROLYTIC: Any brine capable of
causing chemical decornposition of cne or
two dissimilar metals by electrolysis.
15050
BASIC MATERIALS AND METHODS
BRITISH THERMAL UNIT (Btu) :
Btu is defiged
as 778.177 (feet) (pound) if related to the
IT calorie so that I IT cat/ (kilogram) (de—
grees Centr igrade) =
1 Btu/ (pound) (Pahren—
heit), with 1 1b = 453.5924 grams. Approxi—
mately, it is the heat required to raise
the temperature of a pound of water from
59 degrees Fahrenheit to 60 degrees Fahren—
heit.
BUNKER: Space in refrigerator given to ice
or cooling element.
BURNER, AIR ATOMIZING: A• burner in which the
oil is atomized by compressed air which is
forced into and through one or more streams
of oil, breaking the oil into a fine spray.
BURNER ATMOSPHERIC: A gas burner in which air
for cmbustion is entirely supplied by na—
tural draft and the inspirating force creat—
ed by gas velocity through orifices.
BURNER, PECHANICAL ATOMIZING: A burner which
uses the pressure of the oil for atomizing .
BURNER, PRESSURE ATOMIZING:
( See "burner ,
mechanical atomizing") .
BURNER, REGISTER: A burner which contains a
series of air—directing vanes (usually adjust—
able) that are used to direct and/or control
the combustion air flow through the burner .
BURNER, ROTARY ATOMIZING: A burner in which
atomization is accomplished by feeding oil
to the inside of a rapidly rotating cup.
BURNER, STEAM ATOMIZING: A burner for firing
oil which is atomized by steam.
BURNER, THROAT : A sleeve, usually formed of
refractory, located at the burner exit, within
which combustion starts.
BURNER, VAPORIZING: A burner designed to uti—
lize the temperature of the heated combus—
tion chamber to vaporize the liquid fuel fed
into such chamber.
BURNER, WINDBOX: A plenum chamber around a
burner in which an air pressure is maintained
to insure proper distribution and discharge
of secondary air.
CALORIMETER: (1) a device for measuring heat
quantities, such as machine capacity, com—
bust ion heat, specific heat, vital heat, heat
leakage; (2) a device for measuring quality
(0M moisture content) of steam or other
vapor) .
CAPACITY: Usable output of a system or sys—
tem component in which only losses occurring
in the system or component are charged aga inst
CAPACITY, AIR-CONDITIONER, USEFUL LATENT (DE-
HUMIDIFYING) : Available refrigerating capa—
city of an air conditioner for removing "la—
tent heat from space to be conditioned.

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C ION 5050
CAPACITY, AIR-CONDITIONER, USEFUL SENSIBLE: Avail-
able refrigerating capacity of an air conditioner
for removing "sensible heat" from the space to
be conditioned.
CAPACITY, AIR-CONDITIONER, USEFUL TOTAL: Available
refrigerating capacity of an air conditioner for
removing sensible and latent heat from the space
to be conditioned.
CAPACITY, CONDENSING UNIT: Refrigerating effect
in Etuh produced by the difference in total en—
tha I py between refrigerant liquid leaving the
unit and the total enthalpy of the refrigerant
vapor entering. it. Generally measured in ton
or Btuh.
CAPACITY, COOLER REFRIGERANT, NET: The rate of
heat removal from a fluid flowing through a
cooler (air, water, brine) at stated condi—
tions : the dif ference in specific enthalpies
of the cooling fluid entering and leaving the
In case frosting occurs within the
cooler.
cooler, the latent heat of fusion and the sub—
cooling heat Of the ice (frost) must be added
in determining the net cooler refrigerating
capac i ty.
CAPACITY, EXPANSION The refrigerating ef-
fect in joule (btuh or tons, each of 12, 000
Btuh) , produced by the evapora tion of refri—
gerant passed by the valve under specified con—
ditions ,
CAPACITY, ICE-MAKING: Actual productive ability
of a system making ice. This is less than the
rated (ice—making) capacity beca use refr igera—
tion is used in cooling the water to freezing
point, cooling the ice below the freezing point
and overcoming heat leakage.
CAPACITY, ICE-MELTING: Refrigeration equal to
the latent heat of fusion of a stated weight
of ice at 334.94 j/ kg (144Btu/Ib) .
CAPACITY, ICE-MELTING EQUIVALENT: The amount
of heat absorbed by one 0.4536 kg (1 1b.) Of
ice at O degrees Centigrade (32 degrees Fah—
renhe it) in liquefying to water at O degrees
Cent igrade (32 degrees Fahrenheit), 334.94j/
kg (144 Btu/lb) .
The terrn "refrigerat—
CAPACITY, REFRIGERATING :
ing capacity" is used to denote the rate Of
heat removal from a medium or space to be
cooled at stated conditions ;
"refrigera ting ef—
fect:" is used to denote heat transfer to or
from the refrigerant itself in a refrigerating
systern.
CAPACITY, REFRIGERATING, GROSS; The total rate of
heat removal from all sources by the evaporator
Of a refrigerating system at stated conditions .
It is numerically equal to the systan refrigera—
ting effect.
CAPACITY, REFRIGERATING, NET: The remaining rate
of heat removal from all sources by the evapora—
tor of a refrigerating system, at stated condi—
•tions, after deducting internal and external
heat transfers to the evaporator that occurs be—
fore distribution of refrigerating medium and
after its return.
15050
BASIC MATERIALS AND I.ETHODS
CAPACITY, REFRIGERATION, USEFUL: The
frigerating capacity available for the
specific ultimate cooling function for
which the system was designed.
CAPACITY, REFRIGERATING, VOLUMETRIC: The
refrigerating capacity of a system per
unit volume of refrigerant circulated at
the compressor sucti.on.
CAPACITY, REFRIGERATING COMPRESSOR: The
rate of heat removal by the refrigerant
assigned to the compressor in a refrigera—
ting system. This equals the product of
the mass rate of refrigerant flow pro—
duced by the compressor and the differ—
ence in specific enthalpies of the re—
frigerant vapor at its thermodynamic state
entering the compressor and the refri—
gerant liquid at saturation temperature
corresponding to the pressure of vapor
leaving the compressor.
CAPACITY, REFRIGERATING SYSTEM: cooling
effect produced by change in total en—
tha 1 py (formerly called heat content)
between the refrigerant enter ing the
evaporator and the refrigerant leaving
the evaporator.
CAPACITY, REDUCER: In a compressor, a
device, such as a clearance pocket, mov—
able cylinder head, or suction bypass, by
which compressor capacity can be adjusted
without otherwise changing the operating
conditions .
The action by which the sur—
CAPILLARITY :
face of a liquid, where it contacts a
solid (as in a slender tube) , is raised
or lowered .
In refrigeration practice
CAPILLARY TUBE:
a tube of small internal diameter used
as a liquid refrigerant flow control or
expansion device between high and low
sides; also used to transmit pressure
from the sensitive bulb of some tempera—
ture controls to the operating element.
CARBON DIOXIDE ICE: solid C02; dry ice.
CARBONIZATION: Forma tion of carbonaceous
deposits which may be produced by decom—
position Of lubricating Oil or other or—
ganic material e.
CARGO BATTEN : Protection member applied
permanently to the interior of a refri—
gerated compartment to provide air
space between the stowed cargo and the
sides of the compartment.
cargo maintained at an
CARGO, CHILLED:
assigned temperature above its freezing
point .
CARGO, REFRIGERATED: Cargo maintained at
an assigned temperature by means of
mechanical refrigeration .

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SECTION 15050
CEILING OUTLET: A round, square, rectangular
or linear air diffuser in the ceiling which
provides a horizontal di stribution pattern
of prilnary secondary air over the oc—
cupied zone and induces low velocity secon—
day air motion through it.
CELSIUS (CENTIGRADE) : A thermometric scale
in which the freezing point of water is O
degrees and its boiling point 100 degrees
at normal atmospheric pressure (14 . 696 psi) .
CHAMBER, COBUSTION: the space in which com—
bustion takes place.
CHANGE OF STATE: Change from one phase, such
as solid, liquid or gas, to another .
CHILLER (DRIP TRAY): A drawer located direct-
Iy beneath the refrigera ted surfaces of a
manual or sani—automatic defrosting refri—
gerator for food chilling and water collect—
ing during defrosting. It may also serve
as a baffle to regulate compartment ternpera—
ture.
CHILLER (DRIP TRAY) VOLUME: Product of the
mean inside width end length of the tray
and the mean height between the inside
bottom of the tray and the outside bottom
of the surface of the refrigerated pla te
or coil when the tray is in its lowest po—
si ti on.
CHILLING (COOLING) :
Lowering the tempera—
ture of a substance by removing heat in
the. temperature range above freezing .
CHILLING ROOM: A room where products are
cooled prior to cold storage.
CHIMNEY EFFECT: The tendency of air or gas
in a duct or other vertical passage to
rise when heated due to its lower density
in compar ison with that of the surrounding
air or gas; in buildings, the tendency
toward displacement (caused by the differ—
ence in temper ature) of internal heated air
by unhea ted outside air due to the differ—
ence in density of outside and inside air .
CIRCUIT REFRIGERATING: Assembly of refriger-
ant—con taining parts and their connections
used in a refrigerating cycle .
CLASS OF REFRIGERATING SYSTEM: Formerly in
extensive use but now becoming obsolete
due to code change to classif ication rather
than weight, which refers to the total
weight of refrigerant contained, Class A
system is one conta ining 1000 1b or more
of refrigerant; Class B is one containing
more than 100 1b but less than 1000 1b;
Class C is one containing more than 20 1b
but not more than 100 1b; Class D is one
containing more than 6 1b but not more than
20 1b; and Class E is one containing 6 1b
or less.
CLEARANCE :
Space in cylinder not occupied by
pi ston at the end of the compre stroke
or volume of gas remaining in cylinder at
15050
BASIC MATERIALS AND METHODS
the same point measured in percentage Of pis—
ton displacement.
CLEARANCE POCKET: see "capacity reducer" .
CLO: A unit measuring the insulating effect of
clothing on a human subject. 1 clo=O.155
(K.m2) [W.
COEFFICIENT OF PERFORMANCE, COMPRESSOR, HEÄT
PUMP: Ratio of the compressor heating e f—
fect (heat pump) to the rate of energy input
to the shaft of the compressor, in consis—
tent units, in a complete heat pump, under
designated operating conditions .
COEFFICIENT OF PERFORMANCE (HEAT PUMP) : Ratio
of the rate of heat delivered to the rate
of energy input, in consistent units, for a
complete operating heat pump plant or some
specific portion of that plant, under desig—
nated operating conditions .
COEFFICIENT OF PERFORMANCE, COMPRESSOR, RE-
PRIGERATINC: Ratio of Ehe compressor refri—
gerating effect to the rate of energy input
to the shaft of the compressor, in consistent
units, in a complete refrigerating plant, un—
der designated operating conditions .
COEFFICIENT OF PERFORpmNCE (REFRIGERATING) :
Rati.o of the ratp of heat removal to the rate
Of energy input, in consistent uni for a
complete refrigerating plant or some specific
portion of that plant, under designated op—
era ting conditions.
COIL: A cooling or heating element made of pipe
or tubing.
COIL, DIRECT EXPANSION: coil using the direct
refrigeration method.
COIL, EXPANSION: An evaporator constructed of
pipe or tubing.
COIL DECK: Insulated horizontal partition be—
tween refrigerated space and bunker .
COLD STORAGE: A trade or process of preserving
perishables by refrigeration on a large scale.
COMFORT CHART : A chart showing effective tem—
pera tures with dry—bulb temperatures and hu—
midities (and sometimes air motion) , by which
the effects of various air conditions on hu—
man comfort may be compared .
COYEORT COOLING:
Refrigeration for comfort as
opposed to refrigeration for storage or manu—
facture .
COYiFORT LINE: A line on the comfort chart show—
ing relation between the effective tempera ture
and the percentage of adults feeling comfor—
table .
COMFORT ZONE: AVERAGE--the range of effective
temperatures over which the major i ty (50 per—
cent or more) of adults feels comfortable;
range of effective temperatures
over which one or more adults feel comfortable .

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COMPARTMENT, FREEZER: The compartment in a house-
hold refrigerator designed for shor t—term stor—
age Of food at temperatures below O degrees Cen—
In a household
tigrade (32 degrees Fahrenheit) .
combination refrigerator—freezer, it is that
compartment (s) for storage of foods at average
temperatures of —13.3 degrees centi.grade (8 de—
In a household
grees Fahr enheit) or lower .
freezer, is that compartment (s) for extended
storage of frozen foods at a recomrnended rating
temperature of —17.8 degrees Centigrade (O de—
grees Fahrenheit) having Inherent capability
for freezing of food.
COMPARTENT, GENERAL REFRIGERATED: General refri-
gerated compartment (s) in a household refrigera—
tor , all—refrigerator or combination refr igerator—
freezer is that compartment (s) designed for the
refrigerated storage of food at an average tem—
perature above O degrees Centigrade (32 degrees
Fahrenheit). Special compartments designed for
the storage of fresh foods at temperatures near
0 degrees Centigrade (32 degrees Fahrenheit)
shall be considered part of the general refri-
gerator—freezers operating at average tenpera—
tures between —13,3 degrees Centigrade (8 de—
g rees Fahrenheit) and O degrees Centigrade
(32 degrees Fahrenheit) considered part of the
general refrigerated compartment.
COMPRESSION: In a compression refrigeration sys—
tem, a process by which the pressure of the re—
fr igerant is increased.
CCWRESSION, COMPOUND: compression by stages in
two or more cylinders.
Split suction valving ar—
COMPRESSION, DUAL:
rangement on compressor for carrying suc—
tion pressures.
COMPRESSION, MULTISTAGE: compression in,two or
more steps, as where the discharge of one com—
pressor is connected ith the suction of an—
other.
COMPRESSION, RATIO OF: Ratio of absolute pres-
sures after and before compression.
COMPRESSION, SINGLE-STAGE; compression in one
stage.
COMPRESSION, WET: A refrigeration system in
which some liquid refrigerant is mixed with
vapor entering the compressor to cause dis—
cha rge vapors from the compressor to be sat—
ur ated rather than superheated.
COMPRESSION EFFICIENCY: Ratio of work required
to compress adiabatically and reversibly all
vapor del ivered by a compressor (per stage)
to the actual work delivered to the vapor by
the piston of bla des of the compre ssor.
COMPRESSION SYSTEM: Refrigerating systan which
oper ates pressure—irnposing elanent mechanically.
COMPRESSOR, BOOSTER: A compressor for very low
pressures, usually di scharging into the suc—
tion line of another compressor.
15050
COMPRESSOR, CENTRIFUGAL: A nonpositive .
displacement compressor which depends
for pressure rise, at least in part, on
centrifugal effect.
COIQRESSOR, COMPOUND: A compressor in
which compression is accomplished by
stages, as in two or more cylinders.
COMPRESSOR, DOUBLE-ACTING: compressor
which has two compression strokes per
revolution of crankshaft per cylinder ,
i. e. , both faces of the piston are wrk—
ing faces.
Split suction
COMPRESSOR DOUBLE-SUCTION :
va Iving arrangement on compressor for
carrying suction pressures.
COMPRESSOR, HORIZONTAL: Compressor with
hori zontal cylinder or, in small sizes,
with horizontal crankshaft.
COMPRESSOR, MOTOR, SEALED (HERMETIC TYPE) :
See "condensing unit, hermetically sealed"
COMPRESSOR, OPEN-TYPE: A refrigerant com-
pr essor with a shaft or other moving part
extending through its casing to be driven
by an outside source of power, thus re—
guiring a shaft seal or equivalent rubbing
contact between fixed and moving part.
COMPRESSOR POSITIVE DISPLACEMENT: Refri-
gerant compr essor which increases refri—
gerant gas or vapor pressure by chang ing
internal volume of the compression cham—
ber.
Positive dis—
COMPRESSOR, RECIPROCATING;
placement compressor which changes inter—
nal volume of the compression chamber (s)
by reciprocating motion of one or more
pi s tons .
That component
COMPRESSOR, REFRIGERANT :
of a refrigerating system which increases
the pressure of a compressible refr iger—
ant fluid and simultaneously reduces its
volume, while moving the fluid through
the device.
COMPRESSOR, REFRIGERANT, ACCESSIBLE HERMETIC
(SEMI HERMETIC) : A hermetic refrigerant
compressor whose housing is sealed by one
or more gasketed joints and is provided
with means of access for servicing in—
ternal parts in the field.
COMPRESSOR REFRIGERANT, WELDED HER>ET.TC:
A hermetic refrigerant compressor whose
housing is permanently sealed by weld—
ing or brazing and is not provided with
means Of access for servicing internal
parts in the field
ROTARY: A positive displace-
ment compressor which changes internal
volume ot the compression chamber (s) by
Ehe rotary motion Of a positive displace—
ment member (s) .

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SECTION 15050
.CO*PRESSOR, SEALED UNIT:
See "condensing unit,
hermetically sealed" .
COPPRESSOR, SINGLE-ACTING: A compressor hav-
ing one compression stroke per revolution
of the crank for each cylinder.
COMPRESSOR, VERTICAL: compressor with a ver-
tical cylinder or, in small sizes, with a
vertical crankshaft.
COMPRESSOR UNIT, REFRIGERANT: A refrigerat-
ing component designed to compress a spe—
cific refrigerant vapor, consisting of
corpressor, prime mover and regularly fur—
ni shed accessories.
CONCENTRATION : A number specifying composi—
tion of a solution with respect to the con—
stituent names, such as unit (mass) of
salt per unit (vo lume) of brine.
CONDENSATE: Liquid formed by condensation
of a vapor.
In steam hea ting, water con—
densed from steam; in air conditioning ,
water extracted from air, as by cond ensa—
tion on the cooling coil of a refrigera—
tion machine .
CONDENSATION: Process Of changing a vapor
into liquid by extracting heat Condensa—
tion of steam or water vapor is effected
in either steam condensers or dehumidify—
ing coils, and the resulting water is called
condensa te.
CONDENSER (REFRIGERANT) : A heat exchanger in
which the refrigerant, compressed to a suit—
able pressure, is condensed by rejecting
heat to an appropriate external cooling
medium.
CONDENSER, AIR-COOLED REFRIGERANT: A refri-
gerant condenser in which heat rejection
is accomplished entirely by raising the
temperature of the air used as a cooling
medium.
CONDENSER, ATMOSPHERIC REFRIGERANT: A con-
denser cooled with water which is exposed
to the atmosphere.
CONDENSER, EVAPORATIVE REFRIGERANT: A refri-
gerant condenser in which part of the heat
rej ection may be accomplished by raising
the temperature of an air stream passing
over a heat exchange surface and the re—
mainder by evaporating water sprayed or
otherwise distributed cver the heat ex—
change surface.
CONDENSER, OPEN-SHELL-AND-TUBE: one in which
the water passes in a film over the inner
surfaces of the tubes, which are open to
the atmosphere.
CONDENSER, SECONDARY: The condenser of a
secondary system; also, a condenser and a
secondary system where the condenser is
coo led by the evaporator of the secondary
sys tem .
15050
BASIC MATERIALS AND PETHODS
CONDENSER, SUBMERGED : Condenser piping subnerg—
ed in a bath of condenser water.
CONDENSER, WATER-COOLED REFRIGERANT: A refri-
gerant condenser in which heat rej ection is
accanplished entirely by raising the tempera—
ture of the water used as a cooling medium.
CONDENSING REFRIGERATING EFFECT :
Cond ensing
heat added to the refrigerant vapor in refri—
gerant compressor unit.
CONDENSING UNIT, REFRIGERANT: An assembly of
refrigerating components designed to compress
and liquefy a specific refrigerant, consisting
of one or more refrigerant compressors, re—
frigerant condensers, liquid receivers (when
required) , and regulalry furnished accessori—
CONDENSING UNIT, HERMETICALLY SEALED: A sealed
condensing unit in which the housing is per—
manently sealed by welding or brazing and is
not provided with means of access for servic—
ing internal parts in the field.
CONDENSING UNIT, MECHANICAL: A complete high
side of a refrigeration system including the
motor in a unit assembly.
CONDENSING UNIT, MECHANICAL PERFORMANCE FACTOR:
The ratio of its capacity to its energy input,
expressed in Btu per Whr or in tons per kw.
CONDENSING UNIT, SEALED: A mechanical condens-
ing unit in which the compressor and compressor
motor are enclosed in the same housing, with.
no external shaft or shaft seal, arid the com—
pressor motor operating in the refrigerant at—
mo sp her e.
CONDENSING UNIT, SERVICE-SEALED: A sealed con-
densing unit: in which the housing is sealed by
one or more gaskets, and means of access are
provided for servicing internal parts in the
fie Id .
CONDITIONS, STANDARD: A set of physical, chemi-
cal or other parameters of a substance or sys—
tem which defines an accepted reference state
or forms a basis for comparison.
CONDITIONS, STEADY: An operating state of a sys—
tem, including its surroundings, in which the
extent of change with the time of all the
significant parameters is so small as to have
no important effect on the per formance being
observed or measured.
CONDUCTANCE, SURFACE FILM: Time rate of heat flow
per unit area under steady conditions between
a surface and a fluid fcr unit temperature
difference between the two surfaces, under
steady conditions
CONDUCTANCE, THERMAL: Time rate of heat flow j,
through a body (frequently per unit area) from
one of its bounding surfaces to the other for
a unit temperature difference between the two
surfaces, under steady conditions

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SECTION 15050
CONDUCTION, THERMAL: Process of heat transfer
through a rnaterial medium in which kinetic
energy is transmitted by the particles of the
mater ia1 from particle to particle without
gross displacement Of the particles.
CONDUCTIVITY, THERMAL: Time rate of heat flow
through unit area and unit thickness of a homo—
geneous material under steady conditions when
a unit temperature gradient is maintained in
the d irection perpendicular to area. Materi—
als are considered homogeneous when the value
of the thermal conductivity is not affected
by var iation in thickness or in size of the
sample within the range normally used in
construction
CONDUCTOR, THERMAL: A material which readily
transmits heat by means of conduction.
(I) A tube or pipe used for convey—
CONDUIT :
ing fluid; (2) a tube or pipe in which wires
may be enclosed for protection.
CONNECTING ROD: A device connecting the piston
to a crank and used to change rotating mo—
tion into reciprocating motion, or vice versa
as from rotating crankshaft to reciprocating
piston .
System whereby flow is
CONNECTION TN PARALLEL:
divided among two or more channels from a
common starting point or header.
CONTROL: Any device for regulating a system or
component in normal opera tion, manual or
If automatic, implication is that
automat ic .
it is responsive to changes of pressure, tern—
pera ture or any other proper ty whose ragni—
tude is to be regulated.
CONTROL, COMBUSTION: A device or ser ies of de-
vices that control the flow of fuel and com—
bustion air in the desired ratio to provide
for eff icient combustion
CONTROL, DUAL EFFECT: one responsive to tem-
perature of two zones or to two variable
cond it ions .
CONTROL, FINE SAFEGUARD: A system for sensing
the presence or absence of flame indicating ,
alarming or initiating control action.
CONTROL, LIMIT: An automatic safety control res—
ponsive to changes in liquid level, pressure
or temperature or position for limiting op—
eration of the controlled equipment.
CONTROL, PROGRAMMING: A combustion safety con-
trol that provides for various operations at
def inite periods of time in predetermined se—
quences .
CONTROLLED ATMOSPHERE STORAGE (GAS STORAGE) : Ar-
ti ficial addition of carbon dioxide to the at—
mosphere, particularly in large conc entra—
tion, with no attempt to regulate the amount of
oxygen.
15050
BASIC r.mTERIAL.S AND METHODS
CONTROLLER, DIFFERENTIAL: A device used.
to maintain a given difference in pres—
sure or temperature between two pipe
lines or spaces.
CONTROLLER, HIGH-PRESSURE: A pressure con-
troller designed to control the pressure
at a selected point on the high pressure
side of a refrigerating system.
CONTROLLER LOW-PRESSURE: A pressure con-
troller designed to control the pres—
sure at a selected point on the low
pre ssure side of a refrigerating system.
CONVECTION; Heat transfer by the movement
of fluid.
Convection resulting
CONVECTION, FORCED:
from forced circulation of a fluid, as
by a fan, jet or pump.
CONVECTION, NATURAL: Circulation of gas
or liquid (usually air or water) due to
differences in density resulting from
temperature changes .
CONVECTOR: An agency of convection In
heat transfer, a surface designed to trans—
fer its heat to a surrounding fluid large—
Iy or wholly by convection. The heated
fluid may bc removed mechanically or by
gravity (gravity convector) .
Such a sur—
face may or may not be enclosed or con—
cea led •
CONVERSION BURNER: A burner intended for
field installation onto an existing fur—
nace or boiler.
Evaporator for cool—
COOLER, BRINE (WATER) :
ing brine in an indirect system.
COOLER, COLD STORAGE: An insulated room
maintained at —1.1 degrees Centigrade
(30 degrees Fahrenheit) or above.
COOLER, NONPRIMINC: Tubes are omitted
from the top segment of the shell leav—
ing a gas space above the tubes equal
to about one—fourth of the inside shell
diameter.
COOIER, OIL: A heat exchanger for cooling
oil in a lubrication system.
In the form of
COOLER, SENSIBLE HEAT:
cooling surface using •water, brine or
It is
direct expansion refrigerant.
always located on the leaving side of
the dehydrator but frequently treats
in addition a large volume of room air
which is not cirulated through the. de—
hydrator for moisture reduction .
COOLING, DIRECT BETHOD OF: A system in
vülich the. evaporator is in direct con—
tact with the material or space refrigerat—
ed or is located in air—circulating pass—
ages communicating with such space.

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SECTION 15050
t00LING, EVAPORATIVE:
Involves adiabatic
heat exchange between air and a water
spray or wetted surface. The water
assumes the wetbulb temperature of the
air, •which remains constant during its
traverse of the exchanger .
COOLING, INDIRECT METHOD OF: A system in
which a liquid, such as brine or water ,
cooled by the refrigerant, is circulated
the material or space refrigerated or
is used to cool air so circulated ,
COOLING, REGENERATIVE: Process of utiliz-
ing heat which must be rejected or ab—
sorbed in one part of the cycle to func—
tion usefully in another part of the
cycle by heat transfer .
COOLING, SURFACE: A method of cooling air
or other gas by passing it over cold sur—
faces .
COOLING OIL: An arrangement of pipe or
tubing which transfers heat from air to
a refrigerant or brine.
COOLING, EPPECT, SENSIBLE: Difference be-
tween the total cooling effect and the
dehumidifying effect, usually in watts
(Btuh)
COOLING EFFECT, TOTAL: Difference between
the total enthalpy of the dry air and
water vapor mixture entering the cooler
per hour and the total enthalpy of the
dry air and water vapor mixture leaving
the cooler per hour, expressed in watts
(Btuh) .
COOLING ELEMENT: Heat transfer surface
containing refrigerating fluid where
refrigerating effect is desired.
COOLING MEDIUM: Any substance whose temp-
era ture is such that it is used, with or
without a change of state, to lower the
temperature of other bodies or substances .
COOLING RANGE:
In a water cooling device,
the difference between the average temp—
eratures of the water entering and leav—
ing the device.
COOLING WATER: Water for condensation of
refrigerant: condenser water .
CORE SUCKING AND FILLING SYSTEM: A combin-
ation of a pump, distributing piping, hose,
and device by which impure water may be
withdrawn from the unfrozen core of an
ice block; and connecting the source of
water supply, the core may be refilled
with pure water .
CORKBOARD (INSULATION) :
Cork granules ,
cleaned, compressed, and bonded by heat
used for thermal insulation.
15050
BASIC MATERIALS AND METHODS
CORRESPONDING VALUES :
Simultaneous values of
various properties of a fluid, such as pressure,
volume and temperature for a given condition
of fluid.
CORROSIVE: Having a rusting or chemically des—
tructive effect on metals (occasionally on
other materials) .
COUNTERFLOW: In heat exchange between two fluids,
opposite directions of flow; the coldest por—
tion of one meeting the coldest portion of the
other .
CRITICAL VELOCITY: Velocity above which fluid
flow is turbulent.
CRYOGENICS: A study of the production of very
low temperatures and their effect on the prop—
erties of matter.
CRYOHYDRATE: A frozen mixture of water and a
salt; a brine mixed in eutectic proportions
to give the lowest freezing point .
CRYSTAL FORMATION, ZONE OF MAXIMUM: Tempera-
ture range in freezing in which most freezing
takes place, i.e., about —3.9 to —1.1 degrees
centigrade (25 to 30 fahrenheit) for water .
CYCLE, BINARY VAPOR: A refrigerating cycle in
which two separate refrigerants are used, one
superimposed on and augmenting the cycle of
the other .
CYCLE, CARNOT : A sequence of reversible processes
forming the reversible working cycle of an
ideal heat engine of maximum thermal effic—
iency. It consists of isothermal expansion,
adiabatic expansion, isothermal compression,
and adiabatic compression to the initial state .
CYCLE, CLOSED: Any (cycle in which the primary
medium is always enclosed and repeats the
same sequence of events .
CYCLE, DEFROSTING; A refrigeration cycle which
permits the cooling unit to defrost during
off period.
CYCLE, REFRIGERATING, IDEAL BASIC VAPOR COM-
PRESS ION : A closed refrigerating cycle in
which the refrigerant vapor is compressed
reversibly and isentropically; desuperheated
irreversibly and condensed reversibly at
constant pressure; expanded irreversibly and
adiabatically; and evaporated reversibly at
constant pressure .
CYCLE, REFRIGERATING: A sequence of thermody-
namic processes through which a refrigerant
passes, in a closed or open system, to ab—
sorb heat at a relatively low temperature
level and reject heat at a higher temperature
level .
CYCLE REVERSIBLE: Theoretical thermodynamic
cycle, composed of a series of reversible
processes, which can be completely reversed;
e.g., Carnot cycle.

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BASIC MATERIALS AND METHODS
SECTION 15050
days as deg Celsius timeS 1.8 (deg fahrå—
DAMPER: A valve or plate regulating the flow
heit) difference in temperature between
of air or Other fluid.
the mean temperature for the day and 18.3
degrees (65 fahrenheit) .
DAMPER, BAROMETRIC : A device that controls
draft by a balanced damper which bleeds air
( I) condensation of
DEHUMIDIFICATION:
into the breeching on changes of pressure
water vapor from air by cooling below the
to maintain a steady draft,
dew point (2) removal of water vapor from
air by chemical or physical methods .
DAMPER, MULTIPLE LOUVER: A damper having a
number of adjustable blades .
DEHUMIDIFIER: (1) An air cooler or washer
used for lowering moisture content of the
DECIBEL: A unit used in acoustics for expres—
air passing through it; (2) an absorption
sing the relation between two amounts of
or adsorption device for removing moist—
BY definition, the difference in
power .
decibels between two powers (P and P 2) ,
ure from air .
P being the larger, is: db difference
DEHUMIDIFIER, SURFACE: All air-conditioning
equals 10 log 10 2 1 •
unit, designed primarily for cooling and
dehumidifying air through the action of
DECLINATION OF SUN; The angle above or below
passing the air over wet cooling coils .
It is plus if north
the equatorial plane .
of the plane and minus if below. Celestial
DEHUMIDIFYING EFFECT, AIR COOLER: product
objects are located by declination.
of the weight of moisture condensed in
the cooler by the constant 1060 .
DECOMPOSITION: A process of chemical change;
breaking up of structures; spoilage.
( I) Removal of water vapor
DEHYDRATION :
from air by the use of absorbing or ad—
DEFROST, AUTOMATIC: A defrost system in which
sorbing materials; (2) removal of water
the defrost cycle starts and ends automati—
call y, with automatic resumption of normal
from stored goods .
refrigeration at the end of defrost oper—
DENSITY: Ratio of the mass of a specimen
ation. The defrost water is disposed of
of a substance to the volume of the spec—
automatical 1 y.
imen; the mass of a unit volume of a
substance. When weight can be used with—
DEFROST, MANUAL: One in which refrigerated
out confusion, as synonymous with mass,
surface is defrosted by natural or manual
density is the weight per unit volume.
means with manual initiation and termin—
ation of overall defrost operation .
DESICCANT : Any absorbent or adsorbent,
liquid or solid, that removes water or
DEFROST, SEMI-AUTOMATIC: A defrost system
water vapor from a material .
In a re—
in which defrost cycle starts manually and
frigeration circuit, the desiccant should
ends automatically with automatic resump—
be insoluble in the refrigerant.
tion of normal refrigerat:ion at the end of
defrost operation. Defrost water is dis—
DESICCATION ; Any process for evaporating
posed of automatically or collected in a
water or removing water vapor from a
container for subsequent manual removal.
material .
DEFROST, SEMI-AUTOMATIC, FAST:
Same as a
DESIGN WORKING PRESSURE: Maximum allowable
semi—automatic defrost, except that a means
working pressure for which a specific
of accelerating defrosting is provided .
part of a system is designed
DEFROSTING: Process of removing unwanted
DEW POINT, APPARATUS: That temperature
ice or frost from a cooling surface .
which would result if the psychrometric
process occurring in a dehumidifier ,
DEFROSTING, HOT GAS: Use of high pressure
humidifier, or surface cooler were car—
or condenser gas in the evaporator or low
ried to the saturation condition of the
side to effect removal of frost.
leaving air while maintaining the same
ratio of sensible to total heat load in
DEGREE, ELECTRICAL: 360th part of the angle
subtended at the axis of the machine by
the process .
two consecutive field poles of like polar—
DEW POINT RISE: Increase in moisture con-
ity. One mechanical degree thus equals
tent (specific humidity) of air, ex—
as many electrical degrees as there are
pressed in terms of rise in dew point
pairs of poles in the machine.
temperature .
DEGREE DAY : A unit, based on temperature
difference and time; used in estimating
fuel consumption and specifying nominal
heating load of a building in winter .
For any one day, when the mean tempera—
ture is less than 18.3 degrees centigrade
(65 fahrenheit) , there are as many degree
15050
— 10

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SECTION 15050
DEW POINT TEMPERATURE: the temperature at
which condensation of water vapor in a
space begins for a given state of humid—
i ty and pressure as the vapor tempera—
ture is reduced; the temperature corres—
ponding to saturation (100% relative
humidy) for a given absolute humidi ty
at constant pressure.
DIAGRAM, INDICATOR: Pressure-volume dia-
gram tracing condition of gas in a com—
pressor or engine cycle in terms Of
pressure and volume displaced .
DIELECTRIC: An insulator.
DIELECTRIC CONSTANT: Ratio of the elec-
trical capacity of a condenser contain—
ing the material to the capacity of the
same condenser with the material replaced
by a vacuum.
DIELECTRIC STRENGTH: Maximum electric
field that an insulator can withstand
without breakdown.
DIFFERENTIAL: Of a control, difference
between cut—in and cut—out temperatures
or pressures
DIFFUSER, AIR: A circular, square, or
rectangular air distribution outlet,
generally located in the ceiling and
comprised of deflecting members dis—
charging supply air in various direc—
tions and planes and arranged to promote
mixing of primary air with secondary
room air .
DIRECT CONNECTED: Driver and driven, as
motor and compressor, positively con—
nected in line to operate at same speed.
DISPLACEMENT, ACTUAL: Actual volume of
gas or vapor at compressor inlet con—
ditions moved by a compressor per
revolution or per unit of time .
DISPLACEMENT, PISTON: volume swept by
a piston during its working strokes
or stroke per revolution.
DISPLACEMENT, THEORETICAL: Total volume
displaced by the working strokes of all
the pistons of a compressor per revol—
ution or per unit Of time
DISTRIBUTOR: A devise for dividing flow
of liquid fluid between parallel paths
in an evaporator or in other types of
heat transfer apparatus.
DOOR DIKE: A projection on the door which
extends into the refrigerated compart—
ment (s) and which functions primarily
as a barrier to minimize heat: flow to
the interior of the cabinet.
15050
- 11
BASIC MATERIALS AND METHODS
DRAFT: A current of air, when referring to the
pressure difference which causes a current of
air or gases to flow through a flue, chimney ,
heater, or space; or when referring to a loc—
alized effect caused by. one or more factors
of high air velocity, low ambient temperature ,or
direction of air flow, whereby more heat is
withdrawn from a person's skin than is norm—
ally dissipated.
DRAFT, FORCED: Combustion air supplied under
pressure to the fuel burning equipment.
DRAFT, INDUCED: A fan exhausting hot gases
from the heat absorbing equipment.
DRAFT, NATURAL: Difference between atmospheric
pressure and some lower pressure existing in
the furnace or gas passages of heat genera—
ting unit, chimney effect.
DRIER: A manufactured device containing a
desiccant, placed in the refrigerant circuit.
Its primary purpose is to collect and hold
within the desiccant all excessive water in
the system which can be tolerated in the
circulating refrigerant .
DRIFT: In a water spray device, the entrained
unevaporated water carried from the device
by air movement through it .
DRINKING WATER COOLER: An assembly which
ei ther employs or is uSed in conjunction
with a mechanical condensing unit for cool—
ing drinking water
DRINKING WATER COOLER CAPACITY: The amount of
water a cooler will cool in a given ambient
temperature with a given ingoing water temp—
erature and a given outgoing water temperature ,
under steady state conditions .
DRIP: (1) A pipe, or a steam trap and a pipe
considered as a unit, which conducts conden—
sation from the steam side of a piping system
to the water or return side of the system;
(2) water melting from evaporator, or water
dropping from a cooling surface .
DRY: To separate or remove a liquid or vapor
from another substance. The liquid may be
water, but the term is also used for removal
of liquid or vapor forms of other substances .
(a pro—
Solid carbon dioxide, CO
DRY ICE:
2'
prietary term) .
DUCT: A passageway made of sheet metal or
other suitable material, not necessarily
leak tight, used for conveying air or other
gas at low pressures .
DUNNAGE: Strips of wood used in stowing cargo
to provide air space between pieces or pack—
ages .

****** Result for Image/Page 18 ******
BASIC MATERIALS AND METHODS
SECTION 15050
corresponding to the pressure of the vapor
DUST: An air suspension (aerosol) of particles
leaving the compressor.
of any solid material, usually with particle
size less than 100 microns.
EFFECT, REFRIGERATING, CONDENSING UNIT;
Rate of heat removal by the refrigerant
DYNAMOMETER : A device for applying and measuring
assigned €0 the condensing unit in a
power developed by an engine or motor.
refrigerating system. This equal s the
product of the mass rate of refrigerant
EBULLATOR: A device inserted in f looded evap—
flow produced by the condensing unit and
orator tubes to prevent the evaporator from
the difference in the specific enthalpies
becoming oil bound or the refrigerant liquid
of the refrigerant vapor entering the unit
from becoming quiescent at a pressure lower
and the refrigerant liquid leaving the
than its boiling point.
unit .
EFFECT, CHIMNEY: Tendency of air or gas in a
See effect, chimney.
EFFECT, STACK:
duct or other vertical passage to rise when
heated due to its lower density compared to
EFFECT, SUN: Solar energy transmitted into
that of the surrounding air or gas; in build—
interior spaces through windows and build—
ings, tendency toward displacement (caused
ing materials.
by the difference in temperature) of internal
heated air by unheated outside air due to the
EFFECT, TOTAL COOLING: Difference between
difference in density of outside and inside
the total enthalpy of the dry air and
air.
water vapor mixture entering a unit per
hour and the total enthalpy of the dry
EFFECT, COOLING, TOTAL: see effect, total cool-
air and water vapor (and water) mixture
ing .
leaving the unit per hour, in watt (Btuh) .
EFFECT, DEHUMIDIFYING: Heat removed in reducing
EFFICIENCY, COMPRESSION: Ratio of work
the moisture content of air, passing through
required to compress adiabatically and
a dehumidifier, from its entering to its
reversibily all vapor delivered by a
leaving condition .
compressor (per stage) to the actual
work delivered to the vapor by the pis—
EFFECT, HEATING, COMPRESSOR (HEAT PUMP) :
Rate
ton or blades of the compressor .
of heat delivery by the refrigerant assigned
to the compressor in a heat pump system. This
Ratio of the com—
equals the product of the mass rate of refrig—
EFFICIENCY, MECHANICAL:
pression energy or work of a compressor
erant flow produced by the compressor and the
to the energy or work input.
difference in specific enthalpies of the
refrigerant vapor at thermodynamic state
EFFICIENCY, VOLUMETRIC, APPARENT: Ratio
leaving the compressor and saturated liquid
of suction line length on indicator card
refrigerant at the pressure of vapor leaving
to stroke .
the compressor .
EFFICIENCY, VOLUMETRIC, DUE TO CYLINDER
Latent heat of water vap—
EFFECT, HUMIDIFYING:
HEATING: Ratio of •Ehe total to the appar—
ori zation at the average evaporating temper—
ent volumetric efficiency. Also called
ature times the number of pounds of water
real or no—clearance volumetric effic—
evaporated per hour in Btuh.
iency .
EFFECT, REFRIGERATING: Rate of heat removal
EFFICIENCY, VOLUMETRIC, TOTAL: Ratio of
by a refrigerant in a refrigerating system.
the actual volume of gas moved by the
This equal the product of the mass rate of
compressor or pump to actual displace—
refrigerant flow in the system and the
ment of the compressor or pump .
dif ference in specific enthalpies of the
refrigerant at two designated points in
EJECTOR: A device which builds up a high
the system or two designated thermodynamic
fluid velocity in a restricted area to
The term refrig—
states of the refrigerant
obtain a lower static pressure at that
erating effect is used to denote heat trans—
point so that fluid from another source
fer to or from the refrigerant itself in a
may be drawn in.
refrigeration system, whereas refrigerating
capacity denotes the rate of heat removal
ELEMENT, ELECTRIC HEATING; A unit assembly
from a medium or space to be cooled .
consisting of a resistor, insulated
supports, and terminals for connecting
EFFECT, REFRIGERATING, COMPRESSOR; Rate of
the resistor to electric power .
heat removal by the refrigerant assigned
to the compressor in a refrigerating system.
ELEMENT, PRESSURE-IMPOSING: Any device
This equals the product of the mass rate of
or part of the equipment used for increas—
refrigerant flow produced by the compressor
ing pressure on the refrigerant.
and the difference in specific enthalpies
of the refrigerant vapor at its thermo—
dynamic state entering the compressor and
refrigerant liquid at saturation temperature
15050
- 12

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SECTION 15050
BASIC MATERIALS AND METHODS
EMMISSIVITY: The capacity of a material to
EQUALIZER, INTERNAL:
In a thermostatic expan—
emit radiant energy. Emittance is the
sion valve, an integral internal part or
ratio of the total radiant flux emitted
passage whereby the actuating element (dia—
by a body to that emitted by an ideal
phragm or bellows) is exposed to pressure
blackbody at the same temperature.
leaving the valve
EMULSION: A relatively stable suspension of
EQUIVALENT EVAPORATION: The amount of water
small but not colloidal particles of a
a boiler would evaporate, in kilogram per
substance in a liquid, the suspended
second (pound per hour) , if it received and
particles being undissolved.
vaporized feed water at 100 degrees centi—
grade (212 Fahrenheit) and atmospheric pres—
ENERGY, AVAILABLE: The portion of the
sure .
total energy which can be converted to
work in a perfect engine.
EVAPORATION: Change of s tate from liquid to
vapor .
ENERGY, INTERNAL: The sum of all kinetic
and potential energies contained in a
EVAPORATIVE EQUILIBRIUM (OF A WET-BULB INSTRU-
substance due to the states of motion
MENT): The condition attained when the wetted
and separation of its several molecules ,
wick has reached a stable and constant tem—
atoms, and electrons .
It includes
perature. When the instrument is exposed to
sensible heat (vibration energy) and
air at velocities over 4.6m/s (900 fpm), this
that part of the latent heat that is
temperature may be considered to approach
represented by the increase in energy
the true wet—bulb temperature .
during evaporation.
EVAPORATOR (REFRIGERANT): A heat exchanger in
ENGINE :
Prime mover; a device for trans—
which liquid refrigerant, after reducing its
forming fuel or heat energy into mechan—
pressure (expansion) , is evaporated by absorb—
ica1 energy.
ing heat from the medium to be cooled .
ENTHALPY : A thermodynamic property of a
EVAPORATOR, DRY-TYPE: An evaporator of the
substance defined as the sum of its
continuous tube type where refrigerant from
internal energy plus the quantity Pv/J;
a pressure—reducing device is fed into one
where P equals pressure Of the substance,
end and the suction line connects to the
v equals its volume, and J equals the
outlet end.
mechanical equivalent of heat; formerly
called total heat and heat content .
EXFILTRATION: Air flow outward through a wall,
leak membrane, etc.
ENTHALPY, SPECIFIC: Enthalpy per unit
mass of a substance .
EXHAUSTER: A fan used to wi Ehdraw air under
suction.
ENTROPY: The ratio of the heat added to
a substance to the absolute temperature
EXPANSION, COEFFICIENT OF :
The change in
at which it was added.
length per unit length or the change in
volume per unit volume, per degree change
ENTROPY, SPECIFIC:
Entropy per unit of
in temperature .
mass of a substance .
EXPANSION, DRY (DIRECT): A process of heat
ENZYME: Complex organiz substances ( such
removal by a refrigerant in an evaporator
as diastase, pepsin, etc.), capable of
fed by a flow control, responsive to tem—
transforming some other compounds by
perature or pressure, or both, at some point
catalytic action; a soluble ferment.
in the evaporator or to the difference
between high— and low—side pressures and
EQUALIZER: A piping arrangement to main—
not to the liquid level in the evaporator .
tain a common liquid level or pressure
All entering refrigerant is evaporated before
between two or more chambers .
being recirculated .
EQUALIZER, EXTERNAL:
In a thermostatic
EXPANSION, MULTISTAGE:
Passing volatile refrig—
expansion valve, a tube connection from
erant through two or more pressure reducing
a selected control point in the low—
devices, connected in series, usually with
side circuit to the pressure sensing
an evaporator between them, operating at one
side of the control element so that
pressure, and a second evaporator fed through
the control—point pressure is trans—
both devices at a lower pressure.
mitted to the actuating element
(diaphragm or bellows) . This connec—
EXPANSION VALVE PRE$SVRE CHANGE OF: Change in
t ion provides a means for compensating
outlet pressure of a constant pressure expan—
for the pressure drop through access—
sion valve required to open the valve a pre—
ories and the evaporator.
determined amount .
EXPANSION VALVE CAPACITY: Refrigerating effect
in watt (Btuh) or kilogram (ton) produced
by evaporating refrigerant passed by the
valve under specific conditions .
15050
- 13

****** Result for Image/Page 20 ******
SECTION 15050
EXPANSION VALVE STATIC SUPERHEAT: The super-
heat at which the valve begins to open.
EXPANSION VALVE SUPERHEAT: Difference between
the temperature of the thermal bulb and the
temperature corresponding to the pressure at
the outlet or at the equalizer connection,
when provided, Of a thermostatic expansion
valve .
EXTENDED SURFACE: Heat transfer surface, one
side of which is increased in area by adding
fins, discs, or other means .
EXTRUDED: Pushed out through a die. Bars Of
ice, metal rods, shapes, and tubes are made
by this method .
FACTOR OF SAFETY: Ratio of ultimate stress to
design working stress.
FAHRENHEIT: A thermometric scale in which 32
degrees denotes freezing and 212 degrees
the boiling point of water under normal
pressure at sea level (14.696psi) .
FAN: An air—moving device comprising a wheel
or blade, and housing or orifice plate.
FAN, ATTIC: An exhaust fan to discharge air
near the top of a building while cooler air
is forced (drawn) in at a lower level.
FAN, CENTRIFUGAL: fan rotor or wheel within
a scroll—type housing and including driving
mechanism supports for either belt drive or
direct connection .
See exhauster .
FAN, EXHAUST:
FAN, PROPELLER: A propeller or disc-type wheel
within a mounting ring or plate and including
driving mechanism supports for either belt
drive or direct connection.
FAN, TUBEAXiAL: A propeller or disc—type
wheel within a cylinder and including driv—
ing mechanism supports for either belt drive
or direct connection.
FAN, VANEAXIAL: A disc—type wheel within a
cylinder, a set of air guide vanes located
either before or after the wheel, and includ—
ing driving mechanism supports either for
belt drive or direct connection.
FAN SHROUD: A protective housing which sur—
rounds the fan and which may also direct
the flow of air.
FILTER: A device to remove solid material from
a fluid.
FILTER PRESS : A device for separating solid
and liquid matter under pressure so that
the solid residue is compressed into bri—
quettes to facilitate removal .
15050
ANP
FIN: An extended surface to increase the
heat transfer area, as metal sheets
attached to tubes .
FLAMMABILITY : The ability of a material to
burn.
FLARE FITTING: type of soft—tube connector
which requires the flaring of the tube to
provide a mechanical seal.
FLASH CHAMBER: Separating tank placed between
the expansion valve and evaporator in a
refrigeration system to separate and by—
pass any flash gas formed in the expansion
valve .
FLASH POINT: Temperature of combustible
material, as oil, at which there is a suf—
ficient vapori zation to support combustion
of the material.
FLOODBACK: See frost back .
FLOTATION : A method Of treating materials
by f loating in a liquid . An ice—making
method in which ice floats away from the
surface on which it has been frozen.
FLOW, TURBULENT: Fluid flow in which the
fluid moves transfersely as well as in
the direction of the tube or pipe axis,
as opposed to streamline or viscous flow.
Gas, vapor, or liquid.
FLUID :
FLUID, HEAT TRANSFER: Any gas, vapor, or
liquid used to absorb heat from a source
at a high temperature and reject it to a
lower temperature substance .
FLUID, PRIMARY: The refrigerant, to distin—
guish from secondary fluid or brine .
FLUID, REFRIGERATING: Any fluid used to
transfer heat between cold refrigerant
and the substance or bodies to be cooled ,
by circulation of the fluid without change
of state or by an evaporation—condensation
process at essentially equal pressures .
FOAMING: Formation of a foam or froth of
oil—refrigerant due to rapid boiling out
of the refrigerant dissolved in the oil
when pressure is suddenly reduced. This
occurs when the compressor starts oper—
ating, and if large amounts of refriger—
ant have been dissolved, large amounts
of oil may boil out and be carried through
refrigerant lines.
FORECOOLER: In an ice plant, a water—cool—
ing device for ice making before water
enters cans; precooler.
- 14

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SECTION 15050
FREEZE—UP: Failure of a refrigerating
unit to operate normally due to formation
of ice at the expansion device. A valve
may freeze shut or open, causing improper
refrigeration in either case. On a coil,
frost formation to the extent that air flow
stops or is severely restricted.
FREEZER: In cold storage, an insulated room
kept below —I degrees centigrade (30
Fahrenheit) (see carrying freezer and sharp
freezer) ; any device for freezing perish—
ables .
FREEZER, CARRYING: Cold storage freeze room,
generally kept between —28.9 and —6.7 deg—
rees Centigrade (—20 and 20 Fahrenheit) to
receive and hold frozen goods .
FREEZER, HOUSEHOLD: A cabinet designed for
extended storage of frozen food at a recom—
mended temperature of -17.8 degrees Centi—
grade (O Fahrenheit) in a 32.2 degrees
Centigrade (90 Fahrenheit) ambient, with
inherent capability for freezing of food
and a source of refrigeration; and it is
intended for household use.
FREEZER, SHARP:
Cold storage freezer room,
generally kept at —34.4 to —23.3 degrees
Centigrade (—30 to —10 Fahrenheit) to
receive unfrozen goods and freeze them.
FREEZING: Process of changing a liquid
subs tance or the liquid content of a
food or other commodity to a solid state
by removing heat.
FREEZING, QUICK: Freezing of a food or other
commodity at a rpaid rate Of temperature
reduction to produce a desired crystalline
structure in the frozen product.
FREEZING METHOD, REFRIGERATED PLATE :
Heat
transfer by means of the direct contact
of refrigerated plates with the packaged
prod uct.
FREEZING METHOD, SPRAY: Refrigerated liquid
is sprayed into an insulated enclosure
containing the product to be frozen.
FREEZING METHOD, TRAY: A method of freez-
ing food by subjecting it to moving
refrigerated air. The food is arranged
on shallow trays which are placed in port—
able racks and put in an insulated chamber
through which the air is blown .
FREEZING POINT: Temperature at which a given
liquid substance will solidify or freeze
on removal of heat. Freezing point for
water is 0 degrees Centigrade (32 Fahren—
heit) •
FROST BACK: Flooding of liquid from an evap—
orator into the suction line, accompanied
by frost formation on the suction line in
most cases.
15050 — 15
BASIC MATERIALS AND METHODS
FUMES :
Solid particles commonly formed by con—
densing vapors from normally solid materials
such as molten metals. Fumes may also be
formed by sublimation, distillation, calcin—
ation, or chemical reaction wherever such
processes create airborne particles predom—
inantly below one micron in size.
Such solid
particles sometimes serve as condensation
nuclei for water vapor to form smog.
FUSIBLE PLUG: A device having a predetermined
melting temperature member for relief of
pressure.
GAGE (GAUGE)
(I) an instrument for measuring
pressure or liquid level; (2) also, an arbi—
trary scale of measurement for sheet metal
thickness, wire, and drill diameters.
GAS: A usually highly superheated vapor which,
within acceptable limits of accuracy, satis—
fies the perfect gag laws.
GAS, FLASH: The gas resulting from instantan—
eous evaporation of refrigerant in a pressure
reducing device to cool the refrigerant to
the evaporation temperature at a reduced
pressure .
GAS, FOUL:
GAS, INERT:
See gas, noncondensible.
A gas that neither experiences
nor causes chemical reaction nor undergoes
a change of state in a system or process;
nitrogen or helium mixed with a vol—
atile refrigerant.
GAS, NONCONDENSIBLE (FOUL GAS) :
Gas in a
refrigerating system which does not condense
at the temperature and partial pressure at
which it exists in the condenser, therefore
imposing a higher head pressure on the system.
GAS CONSTANT: The coefficient R in the perfect
gas equation pv equals RT.
GAS STORAGE: Artificial addition of carbon
dioxide to the atmosphere, particularly in
large concentration, with no attempt to reg—
ulate the amount of oxygen.
GENERATOR: Basic part of an absorption system.
A still provided with means of heating, used
to drive refrigerant out of solution.
GLASS, GAGE: Device for showing a liquid level .
GLASS, SIGHT: Glass tube used to indicate the
liquid level in tanks, bearings and similar
equipment .
GRADUATED ACTING: Term applied to a control
instrument or device which functions to give
throttling control; permitting operation
between full on and full off position.
GRAVITY, SPECIFIC:
Density compared to density
Of standard material; it usually refers to
water or to air.

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BASIC MATERIALS AND METHODS
SECTION 15050
HEAT EXCHANGER, HEAT PIPE: A bundle of
GRILLE; A louvered or perforated covering for
separate tubes each containing a two—
an air passage opening which can be located in
phase working fluid. A heat source at
the sidewall, ceiling, or floor .
one end evaporates the fluid, the gas is
then condensed by a heat sink at the
In flowing fluid, the
HEAD, DYNAMIC OR TOTAL:
other end. The liquid is returned by
sum of static and velocity pressures at the
gravity or by wick capillary action to
point of measurement.
the tube 's heated portion.
The static pressure of a fluid
HEAD, STATIC:
HEAT EXCHANGER, PLATE: Fixed plates which
expressed in terms of the height of a column
segment and keep separate the hot and cold
of the fluid, or of some manometric fluid, when
fluids .
it would support .
HEAT EXCHANGER, ROTARY: A cylindrical
HEAD, VELOCITY: In a moving fluid, the height of
wheel or drum packed with fluid conduct—
the fluid or of some manometric fluid equiva—
ing heat transfer medium which is rotated
lent to its velocity pressure .
through one fluid and then through a
counter—flowing second fluid.
HEAT; Form Of energy that is transferred by
virtue of a temperature difference.
HEAT EXCHANGER, RUN-AROUND: Finned tube
coils (closed system) or spray chambers
HEAT, HUMID: The ratio of increase of enthalpy
(open system) in which a liquid is cir-
per kg (pound) of dry air, with its associated
culated by gravity or pump action through
moisture, to the rise of temperature under con—
a heat source and then through a heat sink .
ditions of constant pressure and specific
Antifreeze may be used in the coil loop,
humidity .
and a desiccant, in the spray system.
Change of enthalpy during a change
HEAT, LATENT:
HEAT INTERCHANGER: see heat exchanger .
of state, usually expressed in j/ kg (Btu per
pound). With pure substances, latent heat is
HEAT, LATENT, OF CONDENSATION: Difference
absorbed or rejected at constant temperature
in specific enthalpy of a condensible
at any pressure .
fluid between its dry saturated vapor
state and its saturated liquid state
HEAT, LATENT, OP CONDENSATION OR EVAPORATION
at the same pressure.
Thermodynamically, di fference in
(SPECIFIC) :
the specific enthalpies of a pure condensible
HEAT OF FUSION: Latent involved in chang—
fluid between its dry saturated vapor state
ing between the solid and the liquid
and its saturated (not subcooled) liquid state
states .
at the same pressure.
HEAT OF REACTION: Heat per unit mass or
HEAT, SENSIBLE: Heat which is associated with a
per mole of reagents of products of re—
change in temperature; specific heat exchange
action in a chemical reaction; exother—
of temperature; in contrast to a heat inter—
mal if given off, endothermal if absorbed .
change of state (latent heat) occurs .
HEAT OF THE LIQUID: Enthalpy of a mass
HEAT, SPECIFIC: Ratio of the amount of heat
of liquid above an arbitrary zero .
required to raise the temperature Of a given
mass of any substance one degree to the quantity
HEAT PUMP, COOLING AND HEATING: A refrig-
required to raise the temperature of an equal
erating system designed to utilize
mass of a standard substance; usually water at
alternately or simultaneously the heat
15 degrees Centigrade (59 Fahrenheit) one degree.
extracted at a low temperature and the
heat rej ected at a higher temperature
HEAT, VITAL: Heat generated by fruits and veget—
for cooling and heating functions
able; in storage, due to ripening.
respectively.
HEAT CAPACITY: The amount of heat necessary to
HEAT PUMP, HEATING: A refrigerating system
raise the temperature of a given mass one degree.
designed primarily to utilize the heat
Numerically, the mass multiplied by the specific
rejection from the system for a desired
heat.
heating function .
HEAT CONDUCTOR ; A material capable of readily
HEAT REJECTION EFFECT, CONDENSING: That
conducting hteat; opposite of an insulator
portion of the total refrigerant heat
or insulation.
rejecting effect of a condenser which
is used for condensing the entering
HEAT EXCHANGER: A device specifically designed to
refrigerant vapor to a saturated liquid
transfer heat between two physically separated
at the entering refrigerant pressure .
fluids .
15050 - 16

****** Result for Image/Page 1 ******
SECTION 15046
. ACCEPTANCE TEST: An investigation performed
on an individual lot of a previously quali—
fled product, by, or under the observa—
tion of, the purcha ser to establish con—
formity with a purchase agreement.
(PPI)
ACETE PLASTICS: Plastics based on resins
having a predominance of acetal linkages
in main chain.
(PPI)
ACRYLONITRILE-BUTADIENE-STYRENE (ABS) PIPE
AND PITTING PLASTICS: Plastics contain-
ing polymers and/or blends of polymers,
in Which the minimum butadiene content
is 6 percent, the minimum acrylonitrile
content is 15 percent, the minimum sty—
rene and/or substituted styrene content
is 15 percent, and the maximum content
of all other monomers is not more than 5
percent, and lubricants, stabilizers and
colorants.
(PPI)
ADHESIVE: A substance capable of holding
materials together by surface attachment.
(PPI)
ADHESIVE, SOLVENT: An adhesive having a
volatile organic liquid as a vehicle.
See "Solvent Cement" .
(PPI )
(1) The effect on materials of ex—
AGING :
posure to an environment for an interval
of time. (2) The process of exposing
materials to an environment for an interval
of time.
(PPI)
ANT I—OXIDANT : A compounding ingredient add—
ed to a plastic composition to retard possi—
ble degradation from contact with oxygen
(air) particularly in processing at or
exposures to high temperatures.
(PPI )
ARTIFICIAL WEATHERING: The exposure of plas-
tics to cyclic laboratory conditions in—
volving changes in temperature, relative
humidity, and ultraviolet radiant energy,
with or without direct water spray, in an
attanpt to produce changes in the materi—
al similar to those observed after long—
tern continuous outdoor exposure.
(PPI)
Note: The laboratory exposure conditions
are usually intensified beyond those en—
countered in actual outdoor exposure in an
attempt to achieve an accelerated effect.
This definition does not involve exposure
to special conditions such as ozone, salt
spray, industrial gases, etc.
(PPI)
BELL END: The enlarged portion Of a pipe
that resembles the socket portion of a
fitting and that is intended to be used
to make a joint by inserting a piece of
pipe into it. Joining may be accomplish—
ed by solvent cements, adhesives, or
mechanical techniques.
(PPI)
BE*M LOADING: The application of a load to
a pipe between points of support ,
usually expressed in pounds and the dis—
Cance between the centers of the supports.
(PPI)
15046
BURST STENGTH:
PLASTIC PIPE
The internal pressure
quired to break a pipe or f This
pressure will vary with the rate of build—
up of the pressure and the time during
which the pressure is held.
(PPI)
BUTYLENE. PLASTICS:
Plastics based on resins
rlEde by the polymerization Of butene or
copolymerization of butene with one or more
tmsaturated compounds, the butene being in
greatest arnount by weight.
(PPI)
CELLULOSE ACETATE BUTYRATE PLASTICS:
Plastic
txzde by compounding a cellulose acetate—
butyrate ester with plasticizers and other
ingred ients.
cellulose acetate butyrate
ester is a derivative of cellulose (obtain—
from cotton and/or pulp) made by
converting some of the hydroxyl groups in
cellulose to acetate and butyrate groups
with chemicals.
(PPI)
CEMENT: See adhesive and solvents, cement.
(PPI)
(1) The effect of
CHEMICAL RESISTANCE:
specific chemicals on the properties of
plastic piping with respeee to concenera—
tion, temperature and time of exposure.
(2) The ability of a specific plastic pipe
to render service for a useful period in
the transport of a specific chemical at a
specified concentration and temperature.
(PPI)
COLD FLOW: see "Creep"
(PPI)
COMPOUND: The intimate admixture of a polymer
or polymers with other ingredients such as
fillers, softeners, plasticizers, catalysts,
pigments, dyes, curing agents, stabilizers,
anti—oxidants, etc.
(PPI)
COPOLYMER: see "Polymer"
(PPI)
CuEP : The time—dependent part of strain re—
suiting from stress, that is, the dimension—
al change caused by the application of load
over and above the elastic deformation and
with respect to time.
(PPI)
CtJRE : To change the properties of a polymeric
system into a final, more stable, usable
condition by the use Of heat, radiation,
or reaction with chemical additives.
(PPI)
DEFLECTION TEMPERATURE:
The temperature at
which a specimen will deflect a given dis—
tance at a given load under prescribed con—
ditions of test.
See ASTM D648. Formerly
called heat di stortion.
(PPI)
DEGRADATION: A deleterious change in the
chemical structure of a plastic.
see also
"deter ioration " .
(PPI)
DETERIORATION: A permanent change in the phy-
sical properties of a plastic evidenced by
of these properties.
(PPI)

****** Result for Image/Page 2 ******
SECTION 15046
DIFFUSION: The movænent of a material, such as
If
a gas or liquid, in the body of a plastic.
the gas or liquid is absorbed on one side of a
piece of plastic and given off on the other
side, the phenomenon is called permeability.
DS ffusion and permeability are not due to holes
or pores in the plastic but are caused and con—
(PPI)
trolled by chemical mechanisms.
DIMENSION RATIO: The diameter of a pipe divided
by the wall thickness. Each pipe can have
dimension ratios depending on whether the out—
side or inside diameter is used. In practice,
the outside diameter is used if the standard
requirement and manufacturing control are
based on this diameter. The inside diameter is
used when this measurement is the controlling
(PPI)
one.
DRY—BLEND : A free—flowing dry compound prepared
without fluxing or addition of solvent. (PPI)
ELASTICITY: That property of plastics materials
by virtue of which they tend to recover their
original size and shape after deformation.
(PPI)
If the strain is proportional to the
Note :
applied stress, the material is said to exhibit
(PPI)
Hookean or ideal elasticity.
ELASTOMER: A Nterial which at room temperature
can be stretched repeatedly to at least twice
its original length and, upon immediate re—
lease of the stress, will return with force to
its approximate original length. (PPI)
ELEVATED TEMPERATURE TESTING: Tests on plastic
(PPI)
pipe above 23C (73F)
ENVIRONMENTAL STRESS CRACKING: cracks that de-
velop when the material is subjected to stress
in the presence of specific chemicals. (PPI)
Plastics based on resins
ETHYLENE. PLASTICS.
made by the polymerization of ethylene or co—
polymeriza Of ethylene with one or
other unsaturated compounds, the ethylene being
(PPI)
in greatest amount by weight.
EXTRUSION: A method whereby heated or unheated
plastic forced through a shaping orifice be—
(PPI)
comes one continuously formed piece.
FAILURE, ADESIVE: Rupture of an adhesive bond,
such that the plane Of separation appears to
(PPI)
be at the adhesive—adherend interface.
FIBER STRESS: The unit stress, usually in pounds
per square inch (psi) , in a piece of material
that is subjected to an external load. (PPI)
FILLER: A relatively inert material added to a
plastic to its strength, permanence,
working properties, or other q.zaiities, or to
See algo "Reinforced Plastic 't
lower costs.
(PPI )
FORMING: A in which the shape of plastic
pieces such as sheets, rods or tubes is changed
to a desired configuration. See also "Thermo—
(PPI )
forming n
15046
PLASTIC PIPE
Note; The use of the term "forming" In
plastics technology does not include
such operations as molding, casting or
extrusion, in which shapes or pieces
are made from molding materials or
(PPI)
liquids.
FUNGI RESISTANCE: The ability of plastic
pipe to withstand fungi growth and/or
their metabolic products under normal
conditions of service or laboratory
tests simulating such conditions. (PPI)
EAT DISTORTION: see "Deflection tempera-
(PPI)
ture "
(PPI)
I-EAT FORMING: see "Thermoforming" .
JOINING: Making a pipe joint by
heating the edges of the parts to be
joined so that they fuse and become es—
sentially one piece with or without the
addi tion of additional material. (PPI)
HOOP STRESS: The tensile stress, usually
in pounds per sguare inch (psi) , in the
circumferential orientation in the wall
of the pipe when the pipe contains a
gas or liquid under pressure. (PPI)
HYDROSTATIC DESIGN STRESS: The estimated
rrzximum tensile stress in the wall of
the pipe in the circumferential orien—
tation due to internal hydrostatic pres—
sure that can be applied continuously
with a high degree Of certainty that
failure of the pipe will not occur. (PPI)
The hoop
HYDROSTATIC STRENGTH (QUICK) :
stress calculated by means of the ISO
equa tion at which the pipe breaks due to
an internal pressure build—up, usually
(PPI)
within 60 to 90 seconds.
LONG-TERM BURST: The internal pressure at
which a pipe or fitting will break due
to a constant internal pressure held
(PPI)
for 100,000 hours (11.43 years).
IMPACT r IZOD: A specific type of impact
test made with a pendulum type machine.
The specimens are ælded or extruded
with a machined notch in the center. see
(PPI)
ASTM D256.
IMPACT, TUP: A falling weight (tvp) impact
test developed specifically for pipe and
There are several variables
fittings.
that can be selected. See ASTM D 2444.
(PPI )
ISO EQUATION: An equation showing the
interrelations between stress, pressure
and dimensions in pipe, namely :
S = P(ID + t) or P(OD - t)
where S
stress
pressure
average inside diameter
average outside diameter
minimum wali thickness . (PPI)

****** Result for Image/Page 3 ******
SECTION 15046
Ref er ence :
ISO R161-1960 Pipes of Plas-
tics Materials for the Transport of
Fluids (Outside Diameters and Nominal
Pressures) part I, Metric series. (PPI)
JOINT: The location at which two pieces of
pipe or a pipe and a fitting are connected
The joint may be made by an ad—
together .
hesive, a solvent—cement or a mechanical
device such as threads or a ring seal. (PPI)
LONG-TEN*I HYDROSTATIC STRENGTH; The esti-
mated tensile stress in the wall of the
pipe in the circumferential orientation
(hoop stress) that when applied continu—
ously cause failure of the pipe at
100, 000 hours (11.43 years). These
strengths are usually obtained by extrap—
olation of log—log regression equations
or plots.
(PPI)
MOLDING, COMPRESSION: A method of forming
objects from plastics by placing the ma—
terial in a confining mold cavity and ap—
plying pressure and usually heat.
(PPI)
MOLDING, INJECTION: A method of forming
plastic objects from granular or pos•dered
plastics by the fusing of plastic im a
chamber with heat and pressure and then
forcing part of the rnass into a cooler
chamber where it solidifies.
(PPI )
Note : This method is commonly used to
form obj ects from thermoplastics. (PPI)
MONOMER: A relatively simple chemical which
can react to form a polymer. See also
" Polymer t'
(PPI)
Plastics based on resins
NYLON PLASTICS:
composed princ ipaIIy of a long—chain syn—
thetic polymeric amide which has recurring
amide groups as an integral part of the
main polymer cha*m.
(PPI)
Pla stics based on resins
OLEFIN PLASTICS:
made by the polymerization of olefins or
copolymerization of olefins with other un—
saturated compounds, the olefins being in
greatest amount by weight.
Polyethylene ,
polypropylene and polybutyl ene are the most
cormon olefin plastics encountered in
pipe. (PPI)
OUTDOOR EXPOSURE: Plastic pipe placed in ser-
vice or stored so that it is not protected
from the elements of normal 'eather condi—
tions, i.e., the sun's rays, rain, air and
wind. Exposure to industrial and wa ste
gases, chemicals, engine exhausts, etc. ,
are not considered normal "outdoor expo—
sure.
(PPI)
PERMANENCE: The property of a plastic which
describes its resi stance to appreciable
changes in characteristics with time and
env ironm en t.
PERMEABILITY:
(PPI)
See "Diffusion".
PLASTIC PIPE
PLASTIC: A material that contains as aq es-
sential ingredient an organic substance of
large molecular weight, is solid in its
finished state, and, at some stage in its
11Enufactuze or in its processing into
finished articles, can be shaped by flow.
(PPI )
The adjective plastic indicates that the
noun modified is made of, consists Of, or
pertains to plastic.
Note (1) : The above definition may be used
as a separate meaning to the definitions
contained in the dictionary for the adjec—
tive "plastic"
(PPI)
Note (2): The plural form may be used to
refer to two or more plastic materials, for
example, plastics industry. However, when
the intent is to distinguish "plastic prod—
uctsn from "wod products" or "glass prod—
ucts "
the singular form should be used.
As a general rule, if the adjective is to
restrict the noun modified, with respect
to type of material, t' plastic n should be
used; if the adhective is to indicate that
more than one type of plastic material is
or may be involved, "plastics is permissi—
ble.
(PPI)
PLASTICIZER: A rnaterial incorporated in a
plastic to increase its wrkability and its
flexibility or distensibility.
The addition of the plasticizer rnay
Note :
lower the melt viscosity, the temperature of
the second—order transition, or the elastic
modulus of the plastic.
(PPI)
PLASTICS CONDUIT:
Plastic pipe or tubing used
as an enclosure for electrical wiring.
(PPI)
PLASTICS PIPE: A hollow cylinder of a plas-
tic material in Which the wall thicknesses
are usually small when compared to the dia—
meter and in which the inside and outside
walls are essentially concentric.
plastics tubing.
(PPI)
PLASTICS TUBING: A particular size of plas-
tics pipe in which the outside diameter is
essentially the same as that of copper
tubing.
See "plastics pipe " .
(PPI)
POLYBUTYLENE: A polymer prepared by the
polymerization of butene—l as the. sole
See "Polybutyl ene Plastics" and
ronomer.
"Eutylene Plastics. "
(PPI)
POLYBUTYLENE PLASTICS: Plastics based on poly-
mers made with butene—l as essentially the
sole monomer .
(PPI)
POLYETHYLENE: A polymer prepared by the poly-
merization of ethylene as the sole monomer.
See "Polyethylene Plastics" and "Ethylene
Plastics.
(PPI)
POLYETHYLENE PLASTICS :
Plastics based on
polymers made with ethylene as essentially
the so Ie monomer. Note:
In common usage
(PPI)
15046

****** Result for Image/Page 4 ******
SECTION 15046
fov this plastic, essentially means no less than
ethylene and no less than 95% total olefins.
(PPI)
POLYiviER : A compound formed by the reaction of
simple molecules having functional groups that
permit their combination to proceed to high
molecular weights under suitable conditions .
Polymers may be formed by polymerization (addi—
tion polymer) or polycondensation (condensa—
tion polymer ) . When two or more monomers are
involved, the product is called a copolymer.
(PPI)
POLYMERIZATION: A chenical reaction in which
the molecules of a monomer are linked together
to form large molecules whose molecular weight
is a multiple Ot that Of the original sub—
stance. When two or more monomers are involv—
ed, the process is called copolymerization or
(PPI)
heteropolymer ization.
POLYOLEFIN: A polymer prepared by the polymeri—
zation of an olefin (s) as the sole monomer (s) .
See " polyolefin plastics" and "Olefin plas—
(PPI)
tics.
POLYOLEFIN PLASTICS: Plastics based on polymers
made with an olefin (s) as essentially the sole
(PPI)
monomer (s) .
POLYPROPYLENE; A polymer prepared by the poly—
mer ization of propylene as the sole monomer .
See "Polypropylene plastics" and "Propylene
(PPI)
plastics l' •
POLYPROPYLENE PLASTICS: Plastics based on poly-
mers made with propylene as essentially the
(PPI)
sole monomer.
POLYSTYRENE: A plastic based on a resin made
by polymerization of styrene as the sole mono—
(PPI)
See "Styrene plastics" .
mer .
Polystyrene may contain minor propor—
Note:
tions of lubricants, stabilizers, fillers ,
(PPI)
pigments and dyes.
POLY (VINYL CHLORIDE): A resin prepared by the
polymerization of vinyl chloride with or with—
out the addition Of small amounts Of other
(PPI)
monomer s.
PLastics made
POLY (VINYL CHLORIDE) PLASTICS:
by combining po.ly (vinyl chloride) with
colorants, fillers, plasticizers, stabilizers ,
lubricants, other polymers and other compound—
ing ingredients. Not all of these modifiers
(PPI)
are used in pipe compounds.
(PPI )
POWDER BLEND: see "Dry-Blend".
PRESSURE: When expressed with reference to
pipe the force per unit area exerted by the
(PPI)
medium iti the pipe.
PRESSURE RATING: The estimated maximum pres—
sure that the medium in the pipe can exert
continuously with a high degree of certainty
that failure of the pipe will not occur. (PPI)
15046
PLASTIC PIPE
Plastics based on
PROPYLENE PLASTICS:
resins made by the polymerization of
propylene or copolymerization of pro—
pylene with one or more other unsat"rat—
ed compounds, the being in
(PPI)
greatest amount by weight.
QUALIFICATInN TEST: An investigation, in-
dependent of a procurement action, per—
formed on a oroduct to determine whether
or not the *oduct conforms to all re—
quirements of the applicable specifica—
(PPI)
tion.
Note: The examination is usually con—
ducted by the agency responsible for the
specification, the purchaser, or by a
facility approved by the purchaser, at
the request of the supplier seeking in—
clusion of his product on a qualified
(PPI)
products list.
QUICK BURST: The internal pressure requi red
to burst a pipe or fitting due to an
internal pressure build—up, usually with—
(PPI)
in 60 to 90 seconds.
REINFORCED PLASTIC: A plastic with some
strength properties greatly superior to
those of the base resin, resulting from
the presence of high strength fillers
znbedded in the composition. See also
(PPI)
"F i i ler "
RESIN: A solid, semisolid or pseudosolid
organic material which has an indefinite
and often high molecular weight, exhibits
a tendency to flow when subjected to stress ,
usually has a softening or melting range ,
and usually fractures conchoidally. (PPI)
REWORKED MATERIAL (THEPNOPLASTIC) : A plas-
tic material that has been reprocessed,
after having been previously processed
by molding, extrusion, etc., in a fab—
ricator•s plant. (PPI)
RUBBER: A material that is capable of re—
covering from large deformations quickly
(PPI)
and forcibly. See "Elastomer"
SN4PLE : A small part or portion of a
plastic material or product intended
to be representative of the whole. (PPI)
SARAN PLASTICS; Plastics based on resins
made by the polymerization of vinylidene
chloride or copolymerization of vinyli—
dene chlor ide with other unsaturated
compounds , the vinylidene chloride be—
ing in greatest amount of weight. (PPI)
SCHEDULE: A pipe size system (outside
diameters and wall thicknesses) origin—
ated by the iron pipe industry.
SELF-EXTINGUISEIING: The ability of a plas-
tic to ±esist burning when the source of
heat or flame that ignited it is removed.
(PPI)

****** Result for Image/Page 5 ******
SECT$ON 15046
. SERVICE FACTOR: A factor which is used to
reduce a strength value to obtain an
engineering design stress. The factor
may vary depending on the service cond i—
tions, the hazard, the length of service
desired and the properties of the pipe.
(PPI)
SET: TO convert an adhesive into a fixed
or hardened state by chemical or physi—
cal action, such as condensa tion, poly—
merization, oxidation, vulcanization,
gela tion, hydration, or evaporation
of volatile constituents.
See also "Cüren
(PPI)
SOFTENING RANGE: The range of temperature
in which. a plastic changes from a rigid
to a soft state.
(PPI)
Note: Actual values will depend on the
method of test.
Sometimes referred to
as softening point.
(PPI)
SOLVENT CEMENT; In the plastic piping field,
a solvent adhesive that contains a solvent
that dissolves or softens the surfaces
being bonded so that the bonded assembly
becomes essentially one piece of the same
5.
4.
6.3
7.3
5.3
9.
12.5
13.5
11.5
31.5
32.5
30.5
type of plastic.
SOLVENT CEMENTING:
a solvent cement.
(PPI)
(PPI)
Making a pipe joint with
See "Solvent cement"
SPECIMEN : An individual piece or portion Of
a sample used to make a specific test.
specific tests usually require specimens
of specific shape and dimensions. (PPI)
STABILIZER: A compound ing ingredient added
to a plastic composition to retard possi—
ble degradation on exposure to high tern—
peratures, particularly in processing. An
anti —oxidant is a specific kind of stabi—
lizer. (PPI)
STANDARD DIMENSION RATIO; A selected series
of numbers in which the dimensions ratios
are constants for ail sizes of pipe for
each standard dimension ratio and which
are the USÄSI Preferred Nunber Series 10
modified by +1 or —I.
If the outside dia—
meter (OD) is used, the modifier is +1.
If the inside diameter (ID) is used, the modi—
fier is —1. Some of the numbers are as
follows :
USÄSI Preferred
Number Series 10
8.
10.
16.
20.
25.
40.
50.
63.
OD Control
6.
11.
17.
21.
26.
41.
51.
64.
P T AS TTC.
Reference: USASI Preferred Numbers, 417.1—
1958, UDS 389.17.
(PPI)
STANDARD THERMOPLASTIC PIPE MATERIALS DESIGNA-
TION CODE: A means for easily identifying a
thermoplastic pipe material by means of
three elements. The first element is the
abbreviation for the chemical type of the
plastic in accordance with ASTM D1600. The
second is the type and grade (based on prop—
erties in accordance with the ASTM materials
specification) ; in the case of ASTM specifica—
tions which have no types and grades or
those in the cell structure system, two digit
numbers are assigned by the PPI that are used
in place of the larger numbers. The third
is the recommended hydrostatic design stress
(REDS) for water at 23C (73F) in pounds per
square inch divided by 100 and with decimals
dropped, e.g. , PVC 1120 indicates that the
plastic is poly (vinyl chloride) , Type I,
Grade according to ASTM D1784 with a
REDS of 2000 psi for water at 73?. PE 3306
indicates that the plastic is polyethylene
Type 111 Grade 3 according to ASTM D1248
with a NIDS of 630 psi for water at 73F.
PP 1208 is polypropylene, Class 1—19509 in
accordance with ASTM D2i46 with a RHDS of
800 psi for water at 73F; the designation
Of PP12 for polypropylene class 1—19509 will
be covered in the ASTM and Product Standards
for polypropylene pipe when they are issued.
(PPI)
STIFFNESS FACTOR: A physical property of
plastic pipe that indicates the degree of
flexibility of the pipe when subjected to
external loads.
see ASTM D2412.
(PPI)
STRAIN: The ratio of the amount of deformation
to the length being deformed caused by the
application Of a load on a piece of materi—
(PPI )
STRENGTH: The stress required to break, rup—
ture or cause a failure.
(PPI)
STRESS: When expressed with reference to
pipe, the force per unit area in the wall
of the pipe in the circumferential orientatior.
due to internal hydrostatic pressure. (PPI)
STRESS—CRACK: External or internal cracks in a
plastic caused by tensile stresses less than
that of its short-time mechanical strength.
(PPI)
Note: The development of such cracks is
frequently accelerated by the environment
to which the plastic is exposed. The
stresses which cause cracking may be pres—
ent internally or externally or may be
combinations of these stresses. The ap—
pearance of a network Of fine cracks is
called crazing. (PPI)
ID Control
7.
9.
15.
19.
24.
39.
49.
62 .
15046

****** Result for Image/Page 6 ******
PLASTIC PIPE
SECTION 15046
STRESS RELAXATION: The decrease of stress with
respect to time in a piece of plastic that
(PPI)
is subject to an external load.
STYRENE PLASTICS: Plastics based on resins
made by the polymerization of styrene or co—
polymerization of styrene with other unsat—
urated compounds, the styrene being in great—
(PPI)
est amount by weight.
STYRENE-RUBBER PLASTICS: compositions based on
rubbers and styrene plastics, the styrene plas—
tics being in greatest amount by weight. (PPI)
STYRENE-RUBBER (SR) PIPE AND FITTING PLASTICS:
Plastics containing at least 50 percent sty—
rene plastics combined with rubbers and other
compounding materials, but not more than 15
(PPI )
percent acrylonitrile.
SUSTAINED PRESSURE TEST: A constant internal
pressure test for 1000 hours. (PPI)
THERMOFORMING: Forming with the aid of heat.
(PPI)
See also "Forming"
THERMOPLASTIC: A plastic which is thermoplas-
(PPI)
tic in behavior.
Capable of being repeatedly softened by in—
crease of temperature and hardened by decrease
(PPI)
of temperature.
Note; Thermoplastic applies to those materi—
als whose change upon heating is substantially
(PPI)
phys ical.
THERMOSET: A plastic which, when cured by ap—
plication of heat or chemical means, changes
into a substantially infusible and insoluble
(PPI)
product.
Pertaining to the state Of a resin in which
it is relatively infusible. (PPI)
THERMOSETTING: capable of being changed into a
substantially infusible or insoluble product
when cured under application of heat or chemi—
(PPI)
cal means.
VINYL CHLORIDE PLASTICS; Plastics based on resins
made by the polymerization Of vinyl chloride
or copolymerization of vinyl Chloride with
other unsaturated compounds, the vinyl chloride
(PPI)
being in greatest amount by we ight.
VIRGIN 2•mTERIAL: A plastic material in the form of
pellets, granules, powder, floc or liguid that
has not been subjected to use or processing other
than that required for its original manufacture.
(PPI)
WELD—or nilT-LINE: A mark on a molded plastic
formed by the union of two or more streams of
plastic flowing together. (PPI)
15046

****** Result for Image/Page 7 ******
SECTION 15050
(Plumbing, Heating ,
ABSORBENT: A mterial which, due to an af—
finity for certain substances, extracts
one or more such substances from a liquid
or gaseous medium with which it contacts
and which changes physically or chemically,
or both, during the process Calcium chlor—
ide is an example of a solid absorbent,
while solutions of lithium chloride, li—
thium bromide and ethylene glycols are Ii—
quid absorbents .
ABSORPTION : A process whereby a material
extracts one or more substances present in
an atmosphere or mixture of gases or Ii—
quids accompanied by the material ' s phy—
sical and/or chemical changes.
ACCELERATION DUE TO GRAVITY: The rate of
increase in velocity of a body falling
freely in a vacuum. Its value varies with
latitude and elevation. The International
Standard taken at sea level and 45 degrees
latitude is 980.665 cm/s(32.174 f t/ s) .
ACCUMULATOR: A storage chamber for low—side
liquid refrigerant, also known as " surge
drum" or "surge header " ;
also, a pressure
vessel whose volume is used in a refriger—
ant circuit to reduce pulsa tion, also a
pressure vessel connected to more than one
circuit Of a pneumatic systern to obtain the
average pressure of the connected circuits.
ACTIVATED ALUMINA: A form of al uminum oxide
which adsorbs moi sture readily and is used
as a drying agent.
ACTIVATED CARBON: A form of carbon made por—
ous by special treatment by which it is cap—
able of adsorbing various odors, anesthetics
and Other vapors.
ADIABATIC PROCESS: A thermodynamic process
dur ing which no heat is extracted from or
added to the system.
ADSORBENT: A material which has the ability
to cause molecules of gases, liquids or
solids to adhere to its internal surfaces
without chang ing the adsorbent physically
or chemically. Certain so lid materials,
such as silica gel and activated alumina ,
have this property.
ADSORPTION : The action, as sociated with the
surface adherence, of a material in extract—
ing one or more substances present in an at—
mosphere or mixture of gases and liquids ,
unaccompanied by physical or chemical change.
AERATION : Exposing a substance or area to
air circu
AEROSOL; An assemblage of srnaII particles,
solid or liquid, su spended in air. The dia—
meters of particles may vary from 100 microns
to 0.01 micron or less, e.g., dust, fog,
smoke.
15050
BASIC MATERIALS AND METHODS
Refrigerating, Ventilating and Air Conditioning)
AGITATOR: A device causing turbulent motion
in a fluid confined in a tank.
AIR, AMBIENT: Generally, the air surrounding
an object.
AIR, OUTSIDE: External air; atmosphere ex—
ter ior to refrigerated or conditioned space;
ambient (surrounding) air.
AIR, RECIRCULATED; Return air passed through
the conditioner before being resupplied to
the conditioned space.
AIR, REHEATING OF:
In an air conditi oning
system, the final step in treatment in the
event the temperature is too low.
AIR, RETURN: See "air recirculated .
AIR, SATURATED: Moist air in which the partial
pressure of water vapor equals the vapor pres—
sure of water at the existing temperature.
This occurs when dry air and saturated water
vapor coexist at the same dry—bulb temperature.
AIR, SECONDARY : Air for combustion supplied to
the furnace to supplement the primary air.
AIR, STANDARD: Dry air at a pressure of 760 mm
(29.92 in.) Hg at 21 degrees centigrade (69.8
degrees Fahrenheit) temperature and with a
specific volume of O. 833 m 3/ kg (13.33 ft3/Ib) .
AIR BLAST: Forced air circulation.
AIR CHANGE: Introducing new, cleansed, or re—
circulated air to conditioned space, measured
by the number of complete changes per unit
time.
AIR CHANGES : A method of expressing the ænount
of air leakage into or out of a building or
room in terms of the number of building vol—
umes or room volumes exchanged .
AIR CLEANER: A device used to remove airborne
impur ities .
AIR CONDITIONER, ROOM; A factory-made, encased
assembly designed as a unit primarily to pro—
vide free delivery of conditioned air to an
enclosed space, room, or zone .
It includes
a prime source of refrigeration for cooling
and dehumidification and means for circulat—
ing and cleaning air; also means for ventilat—
ing and heating .
AIR CONDITIONING, COMFORT: The process of treat-
ing air to control simultaneously its tempera—
ture, humidity, cleanliness and distr ibution
to meet the comfort requirements of the occu—
pants of the conditioned space .
AIR CONDITIONING, INDUSTRIAL: Air conditioning
for uses other than comf or t.

****** Result for Image/Page 8 ******
SECTION 15050
AIR CPNDITIONING, SUMPER: Comfort air conditioning
used pr imarily when outside tanperature and hu—
midity are above those to be maintained in the
conditioned space.
AIR CONDITIONING, WINTER: Heating, humidifica-
tion, air distribution, and air cleaning, where
outside temperature is below inside room tern—
per ature.
AIR-CONDITIONING UNIT: An assembly of equipment
for the air treatment to control simultaneously
its tanperature, humidity, cleanliness, and
distribution to meet the requirements of a
conå itioned space.
AIR-CONDITIONING UNIT, COOLING (HEATING): A
specific air —treating combination, consisting
of means for venti lation, air circulation, air
cleaning and heat transfer, with control
means for cooling (or heating) .
AIR-CONDITIONING (COOLING) UNIT, SELF-CONTAINED:
An air—conditioning unit having the means for
ventilation, air circulation, air cleaning,
and air cooling, and the controls thereof ,
in the same cabinet with the condensing unit.
Self—con tained air —conditioning units are
(1) re—
classified by the following methods:
j ecting condenser heat (water—cooled and evap—
(2) introducing ventilation
oratively cooled) ;
air (no ventilation, ventilation by drawing
air from outside, ventilation by a combination
of the two methods); and (3) discharging air
to the room (free delivery or pressure type) .
AIR COOLER : factory—encased assembly of ele—
ments whereby the temperature of air passing
through the device is reduced.
AIR COOLER, DRY: Removes sensible heat from
the dehydrated air , whenever it leaves the
dehydrator at an elevated tanperature.
AIR COOLER, DRY-TYPE: A forced circulation air
cooler wherein heat transfer is not implement—
ed by a liquid spray whj.le in operation
AIR COOLER, FORCED CIRCULATION: A cooler in-
cluding a fan or a blower for positive aiY
circulation.
AIR COOLER, FREE DELIVERY: A cooler taking air
from and discharging it directly to the spaée
to be treated without an element external to
the cooler to impose air resistance. e
AIR COOLER, NATURAL CONVECTION: An air cooler
depending on natural convection for air cir—
cu Ia t ion.
AIR COOLER, PRESSURE-TYPE: A cooler for use with
one or more external elements which impose air
resista nce.
AIR TUNNEL: A refrigerated tunnel with rapid air
circulation through which the product to be
frozen is passed.
AIR WASHER: A spray system or device for
cleaning, humidifying or dehumidifying the
air .
15050
BASIC MATERIALS AND METHODS
ALGAE; A minute fresh wa ter plant growth
which forms a scum on the surfaces of re—
circulated water apparatus, interfering
with fluid flow and heat transfer.
ANALYZER: A device in the high side of an
absorption system for increasing concen—
tration of refrigerant in the vapor en—
tering the rectifier or condenser .
ANEMOMETER: An instrument for mea sur ing
the velocity of a fluid.
ANTICIPATING CONTROL: one which, by arti-
ficial means, is actuated sooner than it
muld be without such means to produce a
differential of the controlled
pr operty.
In an evaporative cooling device ,
APPROACH :
the difference between the average tem—
perature of the circulating water leav—
ing the device and the average wet-bulb
ta-nperature of the entering air .
In a
conduction heat exchanger device, the
temperature difference between the leav—
ing treated fluid and the entering work—
ing fluid.
AREA, CORE: The total plane area of the
portion of a grille, face or register
bounded by a line tangent to the outer
edges of the outer openings through
which air can pass.
AREA, FREE: The total minimum opening
area in an air inlet or outlet through
which air can pass.
ASPECT RATIO: In air distribution outlets,
the ratio of the length of the core of
a grille, face or register to width.
In recta ngular ducts, the ratio of width
to depth.
ASPIRATION : Production of movement in a
fluid by suction created by fluid
vel ocity.
ATOMIZE: Reduce to fine spray.
BAFFLE : A surface used for deflecting
fluids, usually in the form of a plate
or wall.
term applied to the hydro—
BALLING :
metric scale used in measuring the
This scale provides
strength of worts.
directly the amount of extract dissolved
in the wort as the weight percentage of
sugar in water.
BAROMETER: Instrument: for measuring a t—
spheric pressure.
BELT DRIVEN: Driver and dr iven, as motor
and compressor, equipped with suitable
sheaves or pulleys and connected by one
or more belts to operate at a speed
ratio establ {shed by the relative dia—
meters of the pulley.

****** Result for Image/Page 9 ******
SECTION 15050
>IMETALLIC ELEMENT: An elanent formed of
metals having dif ferent coefficients of
thermal expansion, used as a temperature
control device.
BLAST HEATER: A set of heat transfer coils
or sections used to heat air which is
drawn or forced through .i.t by a fan.
BLEEDER: Pipe attached, as to a condenser,
to bleed off liquid refrigerant parallel
to main flow.
BLOVER: A fan used to force air under pres—
sure .
BOILER: A Closed vessel In which a liquid
Is heated or vaporized.
BOILER, FIRETUBE: A boiler with straight
tubes, which are surrounded by water and
stearn and through which 'the combusted
products pass.
BOILER, PACKAGED: A boiler equipped and
shipped complete with fuel burning equip—
ment, mechanical draft equipment, auto—
mat ic controls and accessories. Usually
shipped in one or more major sections .
BOILER, WATERTUBE: A boiler in which the
tubes contain v.ater and steam, the heat
being applied to the outside surface.
BOILING POINT: The tanperature at which
the vapor pressure of a liquid equals the
absolute external pressure at the liquid—
vapor interface.
BORE: Inside diameter of a cylinder.
BRAZED: Jointed by fusion using a spelter
on the order of brass; considered equiva—
lent to hard soldering .
BREAKER STRIP , REFRIGERATOR CABINET: A
separate insulating element or integral
insulating extension of the cabinet in—
ter ior surfaces around the per iphery of the
cabinet door or drawer opening (s) , which
functions as a thermal barrier to minimize
heat flow to the cabinet interior .
BREATHER PLUG: A removable plug, cap or
other means of venting a space containing
Insulating material through vaportight
sheathing to the interior of a refrigerat—
ed compartment .
BRINE: Any liquid cooled by the refrigerant
and used for the heat transmission without
a change in its state, having no flash
point or a flash point above 65.6 degrees
Centigrade (150 degrees Fahrenheit) .
BRINE, ELECTROLYTIC: Any brine capable of
causing chemical decornposition of cne or
two dissimilar metals by electrolysis.
15050
BASIC MATERIALS AND METHODS
BRITISH THERMAL UNIT (Btu) :
Btu is defiged
as 778.177 (feet) (pound) if related to the
IT calorie so that I IT cat/ (kilogram) (de—
grees Centr igrade) =
1 Btu/ (pound) (Pahren—
heit), with 1 1b = 453.5924 grams. Approxi—
mately, it is the heat required to raise
the temperature of a pound of water from
59 degrees Fahrenheit to 60 degrees Fahren—
heit.
BUNKER: Space in refrigerator given to ice
or cooling element.
BURNER, AIR ATOMIZING: A• burner in which the
oil is atomized by compressed air which is
forced into and through one or more streams
of oil, breaking the oil into a fine spray.
BURNER ATMOSPHERIC: A gas burner in which air
for cmbustion is entirely supplied by na—
tural draft and the inspirating force creat—
ed by gas velocity through orifices.
BURNER, PECHANICAL ATOMIZING: A burner which
uses the pressure of the oil for atomizing .
BURNER, PRESSURE ATOMIZING:
( See "burner ,
mechanical atomizing") .
BURNER, REGISTER: A burner which contains a
series of air—directing vanes (usually adjust—
able) that are used to direct and/or control
the combustion air flow through the burner .
BURNER, ROTARY ATOMIZING: A burner in which
atomization is accomplished by feeding oil
to the inside of a rapidly rotating cup.
BURNER, STEAM ATOMIZING: A burner for firing
oil which is atomized by steam.
BURNER, THROAT : A sleeve, usually formed of
refractory, located at the burner exit, within
which combustion starts.
BURNER, VAPORIZING: A burner designed to uti—
lize the temperature of the heated combus—
tion chamber to vaporize the liquid fuel fed
into such chamber.
BURNER, WINDBOX: A plenum chamber around a
burner in which an air pressure is maintained
to insure proper distribution and discharge
of secondary air.
CALORIMETER: (1) a device for measuring heat
quantities, such as machine capacity, com—
bust ion heat, specific heat, vital heat, heat
leakage; (2) a device for measuring quality
(0M moisture content) of steam or other
vapor) .
CAPACITY: Usable output of a system or sys—
tem component in which only losses occurring
in the system or component are charged aga inst
CAPACITY, AIR-CONDITIONER, USEFUL LATENT (DE-
HUMIDIFYING) : Available refrigerating capa—
city of an air conditioner for removing "la—
tent heat from space to be conditioned.

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C ION 5050
CAPACITY, AIR-CONDITIONER, USEFUL SENSIBLE: Avail-
able refrigerating capacity of an air conditioner
for removing "sensible heat" from the space to
be conditioned.
CAPACITY, AIR-CONDITIONER, USEFUL TOTAL: Available
refrigerating capacity of an air conditioner for
removing sensible and latent heat from the space
to be conditioned.
CAPACITY, CONDENSING UNIT: Refrigerating effect
in Etuh produced by the difference in total en—
tha I py between refrigerant liquid leaving the
unit and the total enthalpy of the refrigerant
vapor entering. it. Generally measured in ton
or Btuh.
CAPACITY, COOLER REFRIGERANT, NET: The rate of
heat removal from a fluid flowing through a
cooler (air, water, brine) at stated condi—
tions : the dif ference in specific enthalpies
of the cooling fluid entering and leaving the
In case frosting occurs within the
cooler.
cooler, the latent heat of fusion and the sub—
cooling heat Of the ice (frost) must be added
in determining the net cooler refrigerating
capac i ty.
CAPACITY, EXPANSION The refrigerating ef-
fect in joule (btuh or tons, each of 12, 000
Btuh) , produced by the evapora tion of refri—
gerant passed by the valve under specified con—
ditions ,
CAPACITY, ICE-MAKING: Actual productive ability
of a system making ice. This is less than the
rated (ice—making) capacity beca use refr igera—
tion is used in cooling the water to freezing
point, cooling the ice below the freezing point
and overcoming heat leakage.
CAPACITY, ICE-MELTING: Refrigeration equal to
the latent heat of fusion of a stated weight
of ice at 334.94 j/ kg (144Btu/Ib) .
CAPACITY, ICE-MELTING EQUIVALENT: The amount
of heat absorbed by one 0.4536 kg (1 1b.) Of
ice at O degrees Centigrade (32 degrees Fah—
renhe it) in liquefying to water at O degrees
Cent igrade (32 degrees Fahrenheit), 334.94j/
kg (144 Btu/lb) .
The terrn "refrigerat—
CAPACITY, REFRIGERATING :
ing capacity" is used to denote the rate Of
heat removal from a medium or space to be
cooled at stated conditions ;
"refrigera ting ef—
fect:" is used to denote heat transfer to or
from the refrigerant itself in a refrigerating
systern.
CAPACITY, REFRIGERATING, GROSS; The total rate of
heat removal from all sources by the evaporator
Of a refrigerating system at stated conditions .
It is numerically equal to the systan refrigera—
ting effect.
CAPACITY, REFRIGERATING, NET: The remaining rate
of heat removal from all sources by the evapora—
tor of a refrigerating system, at stated condi—
•tions, after deducting internal and external
heat transfers to the evaporator that occurs be—
fore distribution of refrigerating medium and
after its return.
15050
BASIC MATERIALS AND I.ETHODS
CAPACITY, REFRIGERATION, USEFUL: The
frigerating capacity available for the
specific ultimate cooling function for
which the system was designed.
CAPACITY, REFRIGERATING, VOLUMETRIC: The
refrigerating capacity of a system per
unit volume of refrigerant circulated at
the compressor sucti.on.
CAPACITY, REFRIGERATING COMPRESSOR: The
rate of heat removal by the refrigerant
assigned to the compressor in a refrigera—
ting system. This equals the product of
the mass rate of refrigerant flow pro—
duced by the compressor and the differ—
ence in specific enthalpies of the re—
frigerant vapor at its thermodynamic state
entering the compressor and the refri—
gerant liquid at saturation temperature
corresponding to the pressure of vapor
leaving the compressor.
CAPACITY, REFRIGERATING SYSTEM: cooling
effect produced by change in total en—
tha 1 py (formerly called heat content)
between the refrigerant enter ing the
evaporator and the refrigerant leaving
the evaporator.
CAPACITY, REDUCER: In a compressor, a
device, such as a clearance pocket, mov—
able cylinder head, or suction bypass, by
which compressor capacity can be adjusted
without otherwise changing the operating
conditions .
The action by which the sur—
CAPILLARITY :
face of a liquid, where it contacts a
solid (as in a slender tube) , is raised
or lowered .
In refrigeration practice
CAPILLARY TUBE:
a tube of small internal diameter used
as a liquid refrigerant flow control or
expansion device between high and low
sides; also used to transmit pressure
from the sensitive bulb of some tempera—
ture controls to the operating element.
CARBON DIOXIDE ICE: solid C02; dry ice.
CARBONIZATION: Forma tion of carbonaceous
deposits which may be produced by decom—
position Of lubricating Oil or other or—
ganic material e.
CARGO BATTEN : Protection member applied
permanently to the interior of a refri—
gerated compartment to provide air
space between the stowed cargo and the
sides of the compartment.
cargo maintained at an
CARGO, CHILLED:
assigned temperature above its freezing
point .
CARGO, REFRIGERATED: Cargo maintained at
an assigned temperature by means of
mechanical refrigeration .

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SECTION 15050
CEILING OUTLET: A round, square, rectangular
or linear air diffuser in the ceiling which
provides a horizontal di stribution pattern
of prilnary secondary air over the oc—
cupied zone and induces low velocity secon—
day air motion through it.
CELSIUS (CENTIGRADE) : A thermometric scale
in which the freezing point of water is O
degrees and its boiling point 100 degrees
at normal atmospheric pressure (14 . 696 psi) .
CHAMBER, COBUSTION: the space in which com—
bustion takes place.
CHANGE OF STATE: Change from one phase, such
as solid, liquid or gas, to another .
CHILLER (DRIP TRAY): A drawer located direct-
Iy beneath the refrigera ted surfaces of a
manual or sani—automatic defrosting refri—
gerator for food chilling and water collect—
ing during defrosting. It may also serve
as a baffle to regulate compartment ternpera—
ture.
CHILLER (DRIP TRAY) VOLUME: Product of the
mean inside width end length of the tray
and the mean height between the inside
bottom of the tray and the outside bottom
of the surface of the refrigerated pla te
or coil when the tray is in its lowest po—
si ti on.
CHILLING (COOLING) :
Lowering the tempera—
ture of a substance by removing heat in
the. temperature range above freezing .
CHILLING ROOM: A room where products are
cooled prior to cold storage.
CHIMNEY EFFECT: The tendency of air or gas
in a duct or other vertical passage to
rise when heated due to its lower density
in compar ison with that of the surrounding
air or gas; in buildings, the tendency
toward displacement (caused by the differ—
ence in temper ature) of internal heated air
by unhea ted outside air due to the differ—
ence in density of outside and inside air .
CIRCUIT REFRIGERATING: Assembly of refriger-
ant—con taining parts and their connections
used in a refrigerating cycle .
CLASS OF REFRIGERATING SYSTEM: Formerly in
extensive use but now becoming obsolete
due to code change to classif ication rather
than weight, which refers to the total
weight of refrigerant contained, Class A
system is one conta ining 1000 1b or more
of refrigerant; Class B is one containing
more than 100 1b but less than 1000 1b;
Class C is one containing more than 20 1b
but not more than 100 1b; Class D is one
containing more than 6 1b but not more than
20 1b; and Class E is one containing 6 1b
or less.
CLEARANCE :
Space in cylinder not occupied by
pi ston at the end of the compre stroke
or volume of gas remaining in cylinder at
15050
BASIC MATERIALS AND METHODS
the same point measured in percentage Of pis—
ton displacement.
CLEARANCE POCKET: see "capacity reducer" .
CLO: A unit measuring the insulating effect of
clothing on a human subject. 1 clo=O.155
(K.m2) [W.
COEFFICIENT OF PERFORMANCE, COMPRESSOR, HEÄT
PUMP: Ratio of the compressor heating e f—
fect (heat pump) to the rate of energy input
to the shaft of the compressor, in consis—
tent units, in a complete heat pump, under
designated operating conditions .
COEFFICIENT OF PERFORMANCE (HEAT PUMP) : Ratio
of the rate of heat delivered to the rate
of energy input, in consistent units, for a
complete operating heat pump plant or some
specific portion of that plant, under desig—
nated operating conditions .
COEFFICIENT OF PERFORMANCE, COMPRESSOR, RE-
PRIGERATINC: Ratio of Ehe compressor refri—
gerating effect to the rate of energy input
to the shaft of the compressor, in consistent
units, in a complete refrigerating plant, un—
der designated operating conditions .
COEFFICIENT OF PERFORpmNCE (REFRIGERATING) :
Rati.o of the ratp of heat removal to the rate
Of energy input, in consistent uni for a
complete refrigerating plant or some specific
portion of that plant, under designated op—
era ting conditions.
COIL: A cooling or heating element made of pipe
or tubing.
COIL, DIRECT EXPANSION: coil using the direct
refrigeration method.
COIL, EXPANSION: An evaporator constructed of
pipe or tubing.
COIL DECK: Insulated horizontal partition be—
tween refrigerated space and bunker .
COLD STORAGE: A trade or process of preserving
perishables by refrigeration on a large scale.
COMFORT CHART : A chart showing effective tem—
pera tures with dry—bulb temperatures and hu—
midities (and sometimes air motion) , by which
the effects of various air conditions on hu—
man comfort may be compared .
COYEORT COOLING:
Refrigeration for comfort as
opposed to refrigeration for storage or manu—
facture .
COYiFORT LINE: A line on the comfort chart show—
ing relation between the effective tempera ture
and the percentage of adults feeling comfor—
table .
COMFORT ZONE: AVERAGE--the range of effective
temperatures over which the major i ty (50 per—
cent or more) of adults feels comfortable;
range of effective temperatures
over which one or more adults feel comfortable .

****** Result for Image/Page 12 ******
COMPARTMENT, FREEZER: The compartment in a house-
hold refrigerator designed for shor t—term stor—
age Of food at temperatures below O degrees Cen—
In a household
tigrade (32 degrees Fahrenheit) .
combination refrigerator—freezer, it is that
compartment (s) for storage of foods at average
temperatures of —13.3 degrees centi.grade (8 de—
In a household
grees Fahr enheit) or lower .
freezer, is that compartment (s) for extended
storage of frozen foods at a recomrnended rating
temperature of —17.8 degrees Centigrade (O de—
grees Fahrenheit) having Inherent capability
for freezing of food.
COMPARTENT, GENERAL REFRIGERATED: General refri-
gerated compartment (s) in a household refrigera—
tor , all—refrigerator or combination refr igerator—
freezer is that compartment (s) designed for the
refrigerated storage of food at an average tem—
perature above O degrees Centigrade (32 degrees
Fahrenheit). Special compartments designed for
the storage of fresh foods at temperatures near
0 degrees Centigrade (32 degrees Fahrenheit)
shall be considered part of the general refri-
gerator—freezers operating at average tenpera—
tures between —13,3 degrees Centigrade (8 de—
g rees Fahrenheit) and O degrees Centigrade
(32 degrees Fahrenheit) considered part of the
general refrigerated compartment.
COMPRESSION: In a compression refrigeration sys—
tem, a process by which the pressure of the re—
fr igerant is increased.
CCWRESSION, COMPOUND: compression by stages in
two or more cylinders.
Split suction valving ar—
COMPRESSION, DUAL:
rangement on compressor for carrying suc—
tion pressures.
COMPRESSION, MULTISTAGE: compression in,two or
more steps, as where the discharge of one com—
pressor is connected ith the suction of an—
other.
COMPRESSION, RATIO OF: Ratio of absolute pres-
sures after and before compression.
COMPRESSION, SINGLE-STAGE; compression in one
stage.
COMPRESSION, WET: A refrigeration system in
which some liquid refrigerant is mixed with
vapor entering the compressor to cause dis—
cha rge vapors from the compressor to be sat—
ur ated rather than superheated.
COMPRESSION EFFICIENCY: Ratio of work required
to compress adiabatically and reversibly all
vapor del ivered by a compressor (per stage)
to the actual work delivered to the vapor by
the piston of bla des of the compre ssor.
COMPRESSION SYSTEM: Refrigerating systan which
oper ates pressure—irnposing elanent mechanically.
COMPRESSOR, BOOSTER: A compressor for very low
pressures, usually di scharging into the suc—
tion line of another compressor.
15050
COMPRESSOR, CENTRIFUGAL: A nonpositive .
displacement compressor which depends
for pressure rise, at least in part, on
centrifugal effect.
COIQRESSOR, COMPOUND: A compressor in
which compression is accomplished by
stages, as in two or more cylinders.
COMPRESSOR, DOUBLE-ACTING: compressor
which has two compression strokes per
revolution of crankshaft per cylinder ,
i. e. , both faces of the piston are wrk—
ing faces.
Split suction
COMPRESSOR DOUBLE-SUCTION :
va Iving arrangement on compressor for
carrying suction pressures.
COMPRESSOR, HORIZONTAL: Compressor with
hori zontal cylinder or, in small sizes,
with horizontal crankshaft.
COMPRESSOR, MOTOR, SEALED (HERMETIC TYPE) :
See "condensing unit, hermetically sealed"
COMPRESSOR, OPEN-TYPE: A refrigerant com-
pr essor with a shaft or other moving part
extending through its casing to be driven
by an outside source of power, thus re—
guiring a shaft seal or equivalent rubbing
contact between fixed and moving part.
COMPRESSOR POSITIVE DISPLACEMENT: Refri-
gerant compr essor which increases refri—
gerant gas or vapor pressure by chang ing
internal volume of the compression cham—
ber.
Positive dis—
COMPRESSOR, RECIPROCATING;
placement compressor which changes inter—
nal volume of the compression chamber (s)
by reciprocating motion of one or more
pi s tons .
That component
COMPRESSOR, REFRIGERANT :
of a refrigerating system which increases
the pressure of a compressible refr iger—
ant fluid and simultaneously reduces its
volume, while moving the fluid through
the device.
COMPRESSOR, REFRIGERANT, ACCESSIBLE HERMETIC
(SEMI HERMETIC) : A hermetic refrigerant
compressor whose housing is sealed by one
or more gasketed joints and is provided
with means of access for servicing in—
ternal parts in the field.
COMPRESSOR REFRIGERANT, WELDED HER>ET.TC:
A hermetic refrigerant compressor whose
housing is permanently sealed by weld—
ing or brazing and is not provided with
means Of access for servicing internal
parts in the field
ROTARY: A positive displace-
ment compressor which changes internal
volume ot the compression chamber (s) by
Ehe rotary motion Of a positive displace—
ment member (s) .

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SECTION 15050
.CO*PRESSOR, SEALED UNIT:
See "condensing unit,
hermetically sealed" .
COPPRESSOR, SINGLE-ACTING: A compressor hav-
ing one compression stroke per revolution
of the crank for each cylinder.
COMPRESSOR, VERTICAL: compressor with a ver-
tical cylinder or, in small sizes, with a
vertical crankshaft.
COMPRESSOR UNIT, REFRIGERANT: A refrigerat-
ing component designed to compress a spe—
cific refrigerant vapor, consisting of
corpressor, prime mover and regularly fur—
ni shed accessories.
CONCENTRATION : A number specifying composi—
tion of a solution with respect to the con—
stituent names, such as unit (mass) of
salt per unit (vo lume) of brine.
CONDENSATE: Liquid formed by condensation
of a vapor.
In steam hea ting, water con—
densed from steam; in air conditioning ,
water extracted from air, as by cond ensa—
tion on the cooling coil of a refrigera—
tion machine .
CONDENSATION: Process Of changing a vapor
into liquid by extracting heat Condensa—
tion of steam or water vapor is effected
in either steam condensers or dehumidify—
ing coils, and the resulting water is called
condensa te.
CONDENSER (REFRIGERANT) : A heat exchanger in
which the refrigerant, compressed to a suit—
able pressure, is condensed by rejecting
heat to an appropriate external cooling
medium.
CONDENSER, AIR-COOLED REFRIGERANT: A refri-
gerant condenser in which heat rejection
is accomplished entirely by raising the
temperature of the air used as a cooling
medium.
CONDENSER, ATMOSPHERIC REFRIGERANT: A con-
denser cooled with water which is exposed
to the atmosphere.
CONDENSER, EVAPORATIVE REFRIGERANT: A refri-
gerant condenser in which part of the heat
rej ection may be accomplished by raising
the temperature of an air stream passing
over a heat exchange surface and the re—
mainder by evaporating water sprayed or
otherwise distributed cver the heat ex—
change surface.
CONDENSER, OPEN-SHELL-AND-TUBE: one in which
the water passes in a film over the inner
surfaces of the tubes, which are open to
the atmosphere.
CONDENSER, SECONDARY: The condenser of a
secondary system; also, a condenser and a
secondary system where the condenser is
coo led by the evaporator of the secondary
sys tem .
15050
BASIC MATERIALS AND PETHODS
CONDENSER, SUBMERGED : Condenser piping subnerg—
ed in a bath of condenser water.
CONDENSER, WATER-COOLED REFRIGERANT: A refri-
gerant condenser in which heat rej ection is
accanplished entirely by raising the tempera—
ture of the water used as a cooling medium.
CONDENSING REFRIGERATING EFFECT :
Cond ensing
heat added to the refrigerant vapor in refri—
gerant compressor unit.
CONDENSING UNIT, REFRIGERANT: An assembly of
refrigerating components designed to compress
and liquefy a specific refrigerant, consisting
of one or more refrigerant compressors, re—
frigerant condensers, liquid receivers (when
required) , and regulalry furnished accessori—
CONDENSING UNIT, HERMETICALLY SEALED: A sealed
condensing unit in which the housing is per—
manently sealed by welding or brazing and is
not provided with means of access for servic—
ing internal parts in the field.
CONDENSING UNIT, MECHANICAL: A complete high
side of a refrigeration system including the
motor in a unit assembly.
CONDENSING UNIT, MECHANICAL PERFORMANCE FACTOR:
The ratio of its capacity to its energy input,
expressed in Btu per Whr or in tons per kw.
CONDENSING UNIT, SEALED: A mechanical condens-
ing unit in which the compressor and compressor
motor are enclosed in the same housing, with.
no external shaft or shaft seal, arid the com—
pressor motor operating in the refrigerant at—
mo sp her e.
CONDENSING UNIT, SERVICE-SEALED: A sealed con-
densing unit: in which the housing is sealed by
one or more gaskets, and means of access are
provided for servicing internal parts in the
fie Id .
CONDITIONS, STANDARD: A set of physical, chemi-
cal or other parameters of a substance or sys—
tem which defines an accepted reference state
or forms a basis for comparison.
CONDITIONS, STEADY: An operating state of a sys—
tem, including its surroundings, in which the
extent of change with the time of all the
significant parameters is so small as to have
no important effect on the per formance being
observed or measured.
CONDUCTANCE, SURFACE FILM: Time rate of heat flow
per unit area under steady conditions between
a surface and a fluid fcr unit temperature
difference between the two surfaces, under
steady conditions
CONDUCTANCE, THERMAL: Time rate of heat flow j,
through a body (frequently per unit area) from
one of its bounding surfaces to the other for
a unit temperature difference between the two
surfaces, under steady conditions

****** Result for Image/Page 14 ******
SECTION 15050
CONDUCTION, THERMAL: Process of heat transfer
through a rnaterial medium in which kinetic
energy is transmitted by the particles of the
mater ia1 from particle to particle without
gross displacement Of the particles.
CONDUCTIVITY, THERMAL: Time rate of heat flow
through unit area and unit thickness of a homo—
geneous material under steady conditions when
a unit temperature gradient is maintained in
the d irection perpendicular to area. Materi—
als are considered homogeneous when the value
of the thermal conductivity is not affected
by var iation in thickness or in size of the
sample within the range normally used in
construction
CONDUCTOR, THERMAL: A material which readily
transmits heat by means of conduction.
(I) A tube or pipe used for convey—
CONDUIT :
ing fluid; (2) a tube or pipe in which wires
may be enclosed for protection.
CONNECTING ROD: A device connecting the piston
to a crank and used to change rotating mo—
tion into reciprocating motion, or vice versa
as from rotating crankshaft to reciprocating
piston .
System whereby flow is
CONNECTION TN PARALLEL:
divided among two or more channels from a
common starting point or header.
CONTROL: Any device for regulating a system or
component in normal opera tion, manual or
If automatic, implication is that
automat ic .
it is responsive to changes of pressure, tern—
pera ture or any other proper ty whose ragni—
tude is to be regulated.
CONTROL, COMBUSTION: A device or ser ies of de-
vices that control the flow of fuel and com—
bustion air in the desired ratio to provide
for eff icient combustion
CONTROL, DUAL EFFECT: one responsive to tem-
perature of two zones or to two variable
cond it ions .
CONTROL, FINE SAFEGUARD: A system for sensing
the presence or absence of flame indicating ,
alarming or initiating control action.
CONTROL, LIMIT: An automatic safety control res—
ponsive to changes in liquid level, pressure
or temperature or position for limiting op—
eration of the controlled equipment.
CONTROL, PROGRAMMING: A combustion safety con-
trol that provides for various operations at
def inite periods of time in predetermined se—
quences .
CONTROLLED ATMOSPHERE STORAGE (GAS STORAGE) : Ar-
ti ficial addition of carbon dioxide to the at—
mosphere, particularly in large conc entra—
tion, with no attempt to regulate the amount of
oxygen.
15050
BASIC r.mTERIAL.S AND METHODS
CONTROLLER, DIFFERENTIAL: A device used.
to maintain a given difference in pres—
sure or temperature between two pipe
lines or spaces.
CONTROLLER, HIGH-PRESSURE: A pressure con-
troller designed to control the pressure
at a selected point on the high pressure
side of a refrigerating system.
CONTROLLER LOW-PRESSURE: A pressure con-
troller designed to control the pres—
sure at a selected point on the low
pre ssure side of a refrigerating system.
CONVECTION; Heat transfer by the movement
of fluid.
Convection resulting
CONVECTION, FORCED:
from forced circulation of a fluid, as
by a fan, jet or pump.
CONVECTION, NATURAL: Circulation of gas
or liquid (usually air or water) due to
differences in density resulting from
temperature changes .
CONVECTOR: An agency of convection In
heat transfer, a surface designed to trans—
fer its heat to a surrounding fluid large—
Iy or wholly by convection. The heated
fluid may bc removed mechanically or by
gravity (gravity convector) .
Such a sur—
face may or may not be enclosed or con—
cea led •
CONVERSION BURNER: A burner intended for
field installation onto an existing fur—
nace or boiler.
Evaporator for cool—
COOLER, BRINE (WATER) :
ing brine in an indirect system.
COOLER, COLD STORAGE: An insulated room
maintained at —1.1 degrees Centigrade
(30 degrees Fahrenheit) or above.
COOLER, NONPRIMINC: Tubes are omitted
from the top segment of the shell leav—
ing a gas space above the tubes equal
to about one—fourth of the inside shell
diameter.
COOIER, OIL: A heat exchanger for cooling
oil in a lubrication system.
In the form of
COOLER, SENSIBLE HEAT:
cooling surface using •water, brine or
It is
direct expansion refrigerant.
always located on the leaving side of
the dehydrator but frequently treats
in addition a large volume of room air
which is not cirulated through the. de—
hydrator for moisture reduction .
COOLING, DIRECT BETHOD OF: A system in
vülich the. evaporator is in direct con—
tact with the material or space refrigerat—
ed or is located in air—circulating pass—
ages communicating with such space.

****** Result for Image/Page 15 ******
SECTION 15050
t00LING, EVAPORATIVE:
Involves adiabatic
heat exchange between air and a water
spray or wetted surface. The water
assumes the wetbulb temperature of the
air, •which remains constant during its
traverse of the exchanger .
COOLING, INDIRECT METHOD OF: A system in
which a liquid, such as brine or water ,
cooled by the refrigerant, is circulated
the material or space refrigerated or
is used to cool air so circulated ,
COOLING, REGENERATIVE: Process of utiliz-
ing heat which must be rejected or ab—
sorbed in one part of the cycle to func—
tion usefully in another part of the
cycle by heat transfer .
COOLING, SURFACE: A method of cooling air
or other gas by passing it over cold sur—
faces .
COOLING OIL: An arrangement of pipe or
tubing which transfers heat from air to
a refrigerant or brine.
COOLING, EPPECT, SENSIBLE: Difference be-
tween the total cooling effect and the
dehumidifying effect, usually in watts
(Btuh)
COOLING EFFECT, TOTAL: Difference between
the total enthalpy of the dry air and
water vapor mixture entering the cooler
per hour and the total enthalpy of the
dry air and water vapor mixture leaving
the cooler per hour, expressed in watts
(Btuh) .
COOLING ELEMENT: Heat transfer surface
containing refrigerating fluid where
refrigerating effect is desired.
COOLING MEDIUM: Any substance whose temp-
era ture is such that it is used, with or
without a change of state, to lower the
temperature of other bodies or substances .
COOLING RANGE:
In a water cooling device,
the difference between the average temp—
eratures of the water entering and leav—
ing the device.
COOLING WATER: Water for condensation of
refrigerant: condenser water .
CORE SUCKING AND FILLING SYSTEM: A combin-
ation of a pump, distributing piping, hose,
and device by which impure water may be
withdrawn from the unfrozen core of an
ice block; and connecting the source of
water supply, the core may be refilled
with pure water .
CORKBOARD (INSULATION) :
Cork granules ,
cleaned, compressed, and bonded by heat
used for thermal insulation.
15050
BASIC MATERIALS AND METHODS
CORRESPONDING VALUES :
Simultaneous values of
various properties of a fluid, such as pressure,
volume and temperature for a given condition
of fluid.
CORROSIVE: Having a rusting or chemically des—
tructive effect on metals (occasionally on
other materials) .
COUNTERFLOW: In heat exchange between two fluids,
opposite directions of flow; the coldest por—
tion of one meeting the coldest portion of the
other .
CRITICAL VELOCITY: Velocity above which fluid
flow is turbulent.
CRYOGENICS: A study of the production of very
low temperatures and their effect on the prop—
erties of matter.
CRYOHYDRATE: A frozen mixture of water and a
salt; a brine mixed in eutectic proportions
to give the lowest freezing point .
CRYSTAL FORMATION, ZONE OF MAXIMUM: Tempera-
ture range in freezing in which most freezing
takes place, i.e., about —3.9 to —1.1 degrees
centigrade (25 to 30 fahrenheit) for water .
CYCLE, BINARY VAPOR: A refrigerating cycle in
which two separate refrigerants are used, one
superimposed on and augmenting the cycle of
the other .
CYCLE, CARNOT : A sequence of reversible processes
forming the reversible working cycle of an
ideal heat engine of maximum thermal effic—
iency. It consists of isothermal expansion,
adiabatic expansion, isothermal compression,
and adiabatic compression to the initial state .
CYCLE, CLOSED: Any (cycle in which the primary
medium is always enclosed and repeats the
same sequence of events .
CYCLE, DEFROSTING; A refrigeration cycle which
permits the cooling unit to defrost during
off period.
CYCLE, REFRIGERATING, IDEAL BASIC VAPOR COM-
PRESS ION : A closed refrigerating cycle in
which the refrigerant vapor is compressed
reversibly and isentropically; desuperheated
irreversibly and condensed reversibly at
constant pressure; expanded irreversibly and
adiabatically; and evaporated reversibly at
constant pressure .
CYCLE, REFRIGERATING: A sequence of thermody-
namic processes through which a refrigerant
passes, in a closed or open system, to ab—
sorb heat at a relatively low temperature
level and reject heat at a higher temperature
level .
CYCLE REVERSIBLE: Theoretical thermodynamic
cycle, composed of a series of reversible
processes, which can be completely reversed;
e.g., Carnot cycle.

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BASIC MATERIALS AND METHODS
SECTION 15050
days as deg Celsius timeS 1.8 (deg fahrå—
DAMPER: A valve or plate regulating the flow
heit) difference in temperature between
of air or Other fluid.
the mean temperature for the day and 18.3
degrees (65 fahrenheit) .
DAMPER, BAROMETRIC : A device that controls
draft by a balanced damper which bleeds air
( I) condensation of
DEHUMIDIFICATION:
into the breeching on changes of pressure
water vapor from air by cooling below the
to maintain a steady draft,
dew point (2) removal of water vapor from
air by chemical or physical methods .
DAMPER, MULTIPLE LOUVER: A damper having a
number of adjustable blades .
DEHUMIDIFIER: (1) An air cooler or washer
used for lowering moisture content of the
DECIBEL: A unit used in acoustics for expres—
air passing through it; (2) an absorption
sing the relation between two amounts of
or adsorption device for removing moist—
BY definition, the difference in
power .
decibels between two powers (P and P 2) ,
ure from air .
P being the larger, is: db difference
DEHUMIDIFIER, SURFACE: All air-conditioning
equals 10 log 10 2 1 •
unit, designed primarily for cooling and
dehumidifying air through the action of
DECLINATION OF SUN; The angle above or below
passing the air over wet cooling coils .
It is plus if north
the equatorial plane .
of the plane and minus if below. Celestial
DEHUMIDIFYING EFFECT, AIR COOLER: product
objects are located by declination.
of the weight of moisture condensed in
the cooler by the constant 1060 .
DECOMPOSITION: A process of chemical change;
breaking up of structures; spoilage.
( I) Removal of water vapor
DEHYDRATION :
from air by the use of absorbing or ad—
DEFROST, AUTOMATIC: A defrost system in which
sorbing materials; (2) removal of water
the defrost cycle starts and ends automati—
call y, with automatic resumption of normal
from stored goods .
refrigeration at the end of defrost oper—
DENSITY: Ratio of the mass of a specimen
ation. The defrost water is disposed of
of a substance to the volume of the spec—
automatical 1 y.
imen; the mass of a unit volume of a
substance. When weight can be used with—
DEFROST, MANUAL: One in which refrigerated
out confusion, as synonymous with mass,
surface is defrosted by natural or manual
density is the weight per unit volume.
means with manual initiation and termin—
ation of overall defrost operation .
DESICCANT : Any absorbent or adsorbent,
liquid or solid, that removes water or
DEFROST, SEMI-AUTOMATIC: A defrost system
water vapor from a material .
In a re—
in which defrost cycle starts manually and
frigeration circuit, the desiccant should
ends automatically with automatic resump—
be insoluble in the refrigerant.
tion of normal refrigerat:ion at the end of
defrost operation. Defrost water is dis—
DESICCATION ; Any process for evaporating
posed of automatically or collected in a
water or removing water vapor from a
container for subsequent manual removal.
material .
DEFROST, SEMI-AUTOMATIC, FAST:
Same as a
DESIGN WORKING PRESSURE: Maximum allowable
semi—automatic defrost, except that a means
working pressure for which a specific
of accelerating defrosting is provided .
part of a system is designed
DEFROSTING: Process of removing unwanted
DEW POINT, APPARATUS: That temperature
ice or frost from a cooling surface .
which would result if the psychrometric
process occurring in a dehumidifier ,
DEFROSTING, HOT GAS: Use of high pressure
humidifier, or surface cooler were car—
or condenser gas in the evaporator or low
ried to the saturation condition of the
side to effect removal of frost.
leaving air while maintaining the same
ratio of sensible to total heat load in
DEGREE, ELECTRICAL: 360th part of the angle
subtended at the axis of the machine by
the process .
two consecutive field poles of like polar—
DEW POINT RISE: Increase in moisture con-
ity. One mechanical degree thus equals
tent (specific humidity) of air, ex—
as many electrical degrees as there are
pressed in terms of rise in dew point
pairs of poles in the machine.
temperature .
DEGREE DAY : A unit, based on temperature
difference and time; used in estimating
fuel consumption and specifying nominal
heating load of a building in winter .
For any one day, when the mean tempera—
ture is less than 18.3 degrees centigrade
(65 fahrenheit) , there are as many degree
15050
— 10

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SECTION 15050
DEW POINT TEMPERATURE: the temperature at
which condensation of water vapor in a
space begins for a given state of humid—
i ty and pressure as the vapor tempera—
ture is reduced; the temperature corres—
ponding to saturation (100% relative
humidy) for a given absolute humidi ty
at constant pressure.
DIAGRAM, INDICATOR: Pressure-volume dia-
gram tracing condition of gas in a com—
pressor or engine cycle in terms Of
pressure and volume displaced .
DIELECTRIC: An insulator.
DIELECTRIC CONSTANT: Ratio of the elec-
trical capacity of a condenser contain—
ing the material to the capacity of the
same condenser with the material replaced
by a vacuum.
DIELECTRIC STRENGTH: Maximum electric
field that an insulator can withstand
without breakdown.
DIFFERENTIAL: Of a control, difference
between cut—in and cut—out temperatures
or pressures
DIFFUSER, AIR: A circular, square, or
rectangular air distribution outlet,
generally located in the ceiling and
comprised of deflecting members dis—
charging supply air in various direc—
tions and planes and arranged to promote
mixing of primary air with secondary
room air .
DIRECT CONNECTED: Driver and driven, as
motor and compressor, positively con—
nected in line to operate at same speed.
DISPLACEMENT, ACTUAL: Actual volume of
gas or vapor at compressor inlet con—
ditions moved by a compressor per
revolution or per unit of time .
DISPLACEMENT, PISTON: volume swept by
a piston during its working strokes
or stroke per revolution.
DISPLACEMENT, THEORETICAL: Total volume
displaced by the working strokes of all
the pistons of a compressor per revol—
ution or per unit Of time
DISTRIBUTOR: A devise for dividing flow
of liquid fluid between parallel paths
in an evaporator or in other types of
heat transfer apparatus.
DOOR DIKE: A projection on the door which
extends into the refrigerated compart—
ment (s) and which functions primarily
as a barrier to minimize heat: flow to
the interior of the cabinet.
15050
- 11
BASIC MATERIALS AND METHODS
DRAFT: A current of air, when referring to the
pressure difference which causes a current of
air or gases to flow through a flue, chimney ,
heater, or space; or when referring to a loc—
alized effect caused by. one or more factors
of high air velocity, low ambient temperature ,or
direction of air flow, whereby more heat is
withdrawn from a person's skin than is norm—
ally dissipated.
DRAFT, FORCED: Combustion air supplied under
pressure to the fuel burning equipment.
DRAFT, INDUCED: A fan exhausting hot gases
from the heat absorbing equipment.
DRAFT, NATURAL: Difference between atmospheric
pressure and some lower pressure existing in
the furnace or gas passages of heat genera—
ting unit, chimney effect.
DRIER: A manufactured device containing a
desiccant, placed in the refrigerant circuit.
Its primary purpose is to collect and hold
within the desiccant all excessive water in
the system which can be tolerated in the
circulating refrigerant .
DRIFT: In a water spray device, the entrained
unevaporated water carried from the device
by air movement through it .
DRINKING WATER COOLER: An assembly which
ei ther employs or is uSed in conjunction
with a mechanical condensing unit for cool—
ing drinking water
DRINKING WATER COOLER CAPACITY: The amount of
water a cooler will cool in a given ambient
temperature with a given ingoing water temp—
erature and a given outgoing water temperature ,
under steady state conditions .
DRIP: (1) A pipe, or a steam trap and a pipe
considered as a unit, which conducts conden—
sation from the steam side of a piping system
to the water or return side of the system;
(2) water melting from evaporator, or water
dropping from a cooling surface .
DRY: To separate or remove a liquid or vapor
from another substance. The liquid may be
water, but the term is also used for removal
of liquid or vapor forms of other substances .
(a pro—
Solid carbon dioxide, CO
DRY ICE:
2'
prietary term) .
DUCT: A passageway made of sheet metal or
other suitable material, not necessarily
leak tight, used for conveying air or other
gas at low pressures .
DUNNAGE: Strips of wood used in stowing cargo
to provide air space between pieces or pack—
ages .

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BASIC MATERIALS AND METHODS
SECTION 15050
corresponding to the pressure of the vapor
DUST: An air suspension (aerosol) of particles
leaving the compressor.
of any solid material, usually with particle
size less than 100 microns.
EFFECT, REFRIGERATING, CONDENSING UNIT;
Rate of heat removal by the refrigerant
DYNAMOMETER : A device for applying and measuring
assigned €0 the condensing unit in a
power developed by an engine or motor.
refrigerating system. This equal s the
product of the mass rate of refrigerant
EBULLATOR: A device inserted in f looded evap—
flow produced by the condensing unit and
orator tubes to prevent the evaporator from
the difference in the specific enthalpies
becoming oil bound or the refrigerant liquid
of the refrigerant vapor entering the unit
from becoming quiescent at a pressure lower
and the refrigerant liquid leaving the
than its boiling point.
unit .
EFFECT, CHIMNEY: Tendency of air or gas in a
See effect, chimney.
EFFECT, STACK:
duct or other vertical passage to rise when
heated due to its lower density compared to
EFFECT, SUN: Solar energy transmitted into
that of the surrounding air or gas; in build—
interior spaces through windows and build—
ings, tendency toward displacement (caused
ing materials.
by the difference in temperature) of internal
heated air by unheated outside air due to the
EFFECT, TOTAL COOLING: Difference between
difference in density of outside and inside
the total enthalpy of the dry air and
air.
water vapor mixture entering a unit per
hour and the total enthalpy of the dry
EFFECT, COOLING, TOTAL: see effect, total cool-
air and water vapor (and water) mixture
ing .
leaving the unit per hour, in watt (Btuh) .
EFFECT, DEHUMIDIFYING: Heat removed in reducing
EFFICIENCY, COMPRESSION: Ratio of work
the moisture content of air, passing through
required to compress adiabatically and
a dehumidifier, from its entering to its
reversibily all vapor delivered by a
leaving condition .
compressor (per stage) to the actual
work delivered to the vapor by the pis—
EFFECT, HEATING, COMPRESSOR (HEAT PUMP) :
Rate
ton or blades of the compressor .
of heat delivery by the refrigerant assigned
to the compressor in a heat pump system. This
Ratio of the com—
equals the product of the mass rate of refrig—
EFFICIENCY, MECHANICAL:
pression energy or work of a compressor
erant flow produced by the compressor and the
to the energy or work input.
difference in specific enthalpies of the
refrigerant vapor at thermodynamic state
EFFICIENCY, VOLUMETRIC, APPARENT: Ratio
leaving the compressor and saturated liquid
of suction line length on indicator card
refrigerant at the pressure of vapor leaving
to stroke .
the compressor .
EFFICIENCY, VOLUMETRIC, DUE TO CYLINDER
Latent heat of water vap—
EFFECT, HUMIDIFYING:
HEATING: Ratio of •Ehe total to the appar—
ori zation at the average evaporating temper—
ent volumetric efficiency. Also called
ature times the number of pounds of water
real or no—clearance volumetric effic—
evaporated per hour in Btuh.
iency .
EFFECT, REFRIGERATING: Rate of heat removal
EFFICIENCY, VOLUMETRIC, TOTAL: Ratio of
by a refrigerant in a refrigerating system.
the actual volume of gas moved by the
This equal the product of the mass rate of
compressor or pump to actual displace—
refrigerant flow in the system and the
ment of the compressor or pump .
dif ference in specific enthalpies of the
refrigerant at two designated points in
EJECTOR: A device which builds up a high
the system or two designated thermodynamic
fluid velocity in a restricted area to
The term refrig—
states of the refrigerant
obtain a lower static pressure at that
erating effect is used to denote heat trans—
point so that fluid from another source
fer to or from the refrigerant itself in a
may be drawn in.
refrigeration system, whereas refrigerating
capacity denotes the rate of heat removal
ELEMENT, ELECTRIC HEATING; A unit assembly
from a medium or space to be cooled .
consisting of a resistor, insulated
supports, and terminals for connecting
EFFECT, REFRIGERATING, COMPRESSOR; Rate of
the resistor to electric power .
heat removal by the refrigerant assigned
to the compressor in a refrigerating system.
ELEMENT, PRESSURE-IMPOSING: Any device
This equals the product of the mass rate of
or part of the equipment used for increas—
refrigerant flow produced by the compressor
ing pressure on the refrigerant.
and the difference in specific enthalpies
of the refrigerant vapor at its thermo—
dynamic state entering the compressor and
refrigerant liquid at saturation temperature
15050
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SECTION 15050
BASIC MATERIALS AND METHODS
EMMISSIVITY: The capacity of a material to
EQUALIZER, INTERNAL:
In a thermostatic expan—
emit radiant energy. Emittance is the
sion valve, an integral internal part or
ratio of the total radiant flux emitted
passage whereby the actuating element (dia—
by a body to that emitted by an ideal
phragm or bellows) is exposed to pressure
blackbody at the same temperature.
leaving the valve
EMULSION: A relatively stable suspension of
EQUIVALENT EVAPORATION: The amount of water
small but not colloidal particles of a
a boiler would evaporate, in kilogram per
substance in a liquid, the suspended
second (pound per hour) , if it received and
particles being undissolved.
vaporized feed water at 100 degrees centi—
grade (212 Fahrenheit) and atmospheric pres—
ENERGY, AVAILABLE: The portion of the
sure .
total energy which can be converted to
work in a perfect engine.
EVAPORATION: Change of s tate from liquid to
vapor .
ENERGY, INTERNAL: The sum of all kinetic
and potential energies contained in a
EVAPORATIVE EQUILIBRIUM (OF A WET-BULB INSTRU-
substance due to the states of motion
MENT): The condition attained when the wetted
and separation of its several molecules ,
wick has reached a stable and constant tem—
atoms, and electrons .
It includes
perature. When the instrument is exposed to
sensible heat (vibration energy) and
air at velocities over 4.6m/s (900 fpm), this
that part of the latent heat that is
temperature may be considered to approach
represented by the increase in energy
the true wet—bulb temperature .
during evaporation.
EVAPORATOR (REFRIGERANT): A heat exchanger in
ENGINE :
Prime mover; a device for trans—
which liquid refrigerant, after reducing its
forming fuel or heat energy into mechan—
pressure (expansion) , is evaporated by absorb—
ica1 energy.
ing heat from the medium to be cooled .
ENTHALPY : A thermodynamic property of a
EVAPORATOR, DRY-TYPE: An evaporator of the
substance defined as the sum of its
continuous tube type where refrigerant from
internal energy plus the quantity Pv/J;
a pressure—reducing device is fed into one
where P equals pressure Of the substance,
end and the suction line connects to the
v equals its volume, and J equals the
outlet end.
mechanical equivalent of heat; formerly
called total heat and heat content .
EXFILTRATION: Air flow outward through a wall,
leak membrane, etc.
ENTHALPY, SPECIFIC: Enthalpy per unit
mass of a substance .
EXHAUSTER: A fan used to wi Ehdraw air under
suction.
ENTROPY: The ratio of the heat added to
a substance to the absolute temperature
EXPANSION, COEFFICIENT OF :
The change in
at which it was added.
length per unit length or the change in
volume per unit volume, per degree change
ENTROPY, SPECIFIC:
Entropy per unit of
in temperature .
mass of a substance .
EXPANSION, DRY (DIRECT): A process of heat
ENZYME: Complex organiz substances ( such
removal by a refrigerant in an evaporator
as diastase, pepsin, etc.), capable of
fed by a flow control, responsive to tem—
transforming some other compounds by
perature or pressure, or both, at some point
catalytic action; a soluble ferment.
in the evaporator or to the difference
between high— and low—side pressures and
EQUALIZER: A piping arrangement to main—
not to the liquid level in the evaporator .
tain a common liquid level or pressure
All entering refrigerant is evaporated before
between two or more chambers .
being recirculated .
EQUALIZER, EXTERNAL:
In a thermostatic
EXPANSION, MULTISTAGE:
Passing volatile refrig—
expansion valve, a tube connection from
erant through two or more pressure reducing
a selected control point in the low—
devices, connected in series, usually with
side circuit to the pressure sensing
an evaporator between them, operating at one
side of the control element so that
pressure, and a second evaporator fed through
the control—point pressure is trans—
both devices at a lower pressure.
mitted to the actuating element
(diaphragm or bellows) . This connec—
EXPANSION VALVE PRE$SVRE CHANGE OF: Change in
t ion provides a means for compensating
outlet pressure of a constant pressure expan—
for the pressure drop through access—
sion valve required to open the valve a pre—
ories and the evaporator.
determined amount .
EXPANSION VALVE CAPACITY: Refrigerating effect
in watt (Btuh) or kilogram (ton) produced
by evaporating refrigerant passed by the
valve under specific conditions .
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- 13

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SECTION 15050
EXPANSION VALVE STATIC SUPERHEAT: The super-
heat at which the valve begins to open.
EXPANSION VALVE SUPERHEAT: Difference between
the temperature of the thermal bulb and the
temperature corresponding to the pressure at
the outlet or at the equalizer connection,
when provided, Of a thermostatic expansion
valve .
EXTENDED SURFACE: Heat transfer surface, one
side of which is increased in area by adding
fins, discs, or other means .
EXTRUDED: Pushed out through a die. Bars Of
ice, metal rods, shapes, and tubes are made
by this method .
FACTOR OF SAFETY: Ratio of ultimate stress to
design working stress.
FAHRENHEIT: A thermometric scale in which 32
degrees denotes freezing and 212 degrees
the boiling point of water under normal
pressure at sea level (14.696psi) .
FAN: An air—moving device comprising a wheel
or blade, and housing or orifice plate.
FAN, ATTIC: An exhaust fan to discharge air
near the top of a building while cooler air
is forced (drawn) in at a lower level.
FAN, CENTRIFUGAL: fan rotor or wheel within
a scroll—type housing and including driving
mechanism supports for either belt drive or
direct connection .
See exhauster .
FAN, EXHAUST:
FAN, PROPELLER: A propeller or disc-type wheel
within a mounting ring or plate and including
driving mechanism supports for either belt
drive or direct connection.
FAN, TUBEAXiAL: A propeller or disc—type
wheel within a cylinder and including driv—
ing mechanism supports for either belt drive
or direct connection.
FAN, VANEAXIAL: A disc—type wheel within a
cylinder, a set of air guide vanes located
either before or after the wheel, and includ—
ing driving mechanism supports either for
belt drive or direct connection.
FAN SHROUD: A protective housing which sur—
rounds the fan and which may also direct
the flow of air.
FILTER: A device to remove solid material from
a fluid.
FILTER PRESS : A device for separating solid
and liquid matter under pressure so that
the solid residue is compressed into bri—
quettes to facilitate removal .
15050
ANP
FIN: An extended surface to increase the
heat transfer area, as metal sheets
attached to tubes .
FLAMMABILITY : The ability of a material to
burn.
FLARE FITTING: type of soft—tube connector
which requires the flaring of the tube to
provide a mechanical seal.
FLASH CHAMBER: Separating tank placed between
the expansion valve and evaporator in a
refrigeration system to separate and by—
pass any flash gas formed in the expansion
valve .
FLASH POINT: Temperature of combustible
material, as oil, at which there is a suf—
ficient vapori zation to support combustion
of the material.
FLOODBACK: See frost back .
FLOTATION : A method Of treating materials
by f loating in a liquid . An ice—making
method in which ice floats away from the
surface on which it has been frozen.
FLOW, TURBULENT: Fluid flow in which the
fluid moves transfersely as well as in
the direction of the tube or pipe axis,
as opposed to streamline or viscous flow.
Gas, vapor, or liquid.
FLUID :
FLUID, HEAT TRANSFER: Any gas, vapor, or
liquid used to absorb heat from a source
at a high temperature and reject it to a
lower temperature substance .
FLUID, PRIMARY: The refrigerant, to distin—
guish from secondary fluid or brine .
FLUID, REFRIGERATING: Any fluid used to
transfer heat between cold refrigerant
and the substance or bodies to be cooled ,
by circulation of the fluid without change
of state or by an evaporation—condensation
process at essentially equal pressures .
FOAMING: Formation of a foam or froth of
oil—refrigerant due to rapid boiling out
of the refrigerant dissolved in the oil
when pressure is suddenly reduced. This
occurs when the compressor starts oper—
ating, and if large amounts of refriger—
ant have been dissolved, large amounts
of oil may boil out and be carried through
refrigerant lines.
FORECOOLER: In an ice plant, a water—cool—
ing device for ice making before water
enters cans; precooler.
- 14

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SECTION 15050
FREEZE—UP: Failure of a refrigerating
unit to operate normally due to formation
of ice at the expansion device. A valve
may freeze shut or open, causing improper
refrigeration in either case. On a coil,
frost formation to the extent that air flow
stops or is severely restricted.
FREEZER: In cold storage, an insulated room
kept below —I degrees centigrade (30
Fahrenheit) (see carrying freezer and sharp
freezer) ; any device for freezing perish—
ables .
FREEZER, CARRYING: Cold storage freeze room,
generally kept between —28.9 and —6.7 deg—
rees Centigrade (—20 and 20 Fahrenheit) to
receive and hold frozen goods .
FREEZER, HOUSEHOLD: A cabinet designed for
extended storage of frozen food at a recom—
mended temperature of -17.8 degrees Centi—
grade (O Fahrenheit) in a 32.2 degrees
Centigrade (90 Fahrenheit) ambient, with
inherent capability for freezing of food
and a source of refrigeration; and it is
intended for household use.
FREEZER, SHARP:
Cold storage freezer room,
generally kept at —34.4 to —23.3 degrees
Centigrade (—30 to —10 Fahrenheit) to
receive unfrozen goods and freeze them.
FREEZING: Process of changing a liquid
subs tance or the liquid content of a
food or other commodity to a solid state
by removing heat.
FREEZING, QUICK: Freezing of a food or other
commodity at a rpaid rate Of temperature
reduction to produce a desired crystalline
structure in the frozen product.
FREEZING METHOD, REFRIGERATED PLATE :
Heat
transfer by means of the direct contact
of refrigerated plates with the packaged
prod uct.
FREEZING METHOD, SPRAY: Refrigerated liquid
is sprayed into an insulated enclosure
containing the product to be frozen.
FREEZING METHOD, TRAY: A method of freez-
ing food by subjecting it to moving
refrigerated air. The food is arranged
on shallow trays which are placed in port—
able racks and put in an insulated chamber
through which the air is blown .
FREEZING POINT: Temperature at which a given
liquid substance will solidify or freeze
on removal of heat. Freezing point for
water is 0 degrees Centigrade (32 Fahren—
heit) •
FROST BACK: Flooding of liquid from an evap—
orator into the suction line, accompanied
by frost formation on the suction line in
most cases.
15050 — 15
BASIC MATERIALS AND METHODS
FUMES :
Solid particles commonly formed by con—
densing vapors from normally solid materials
such as molten metals. Fumes may also be
formed by sublimation, distillation, calcin—
ation, or chemical reaction wherever such
processes create airborne particles predom—
inantly below one micron in size.
Such solid
particles sometimes serve as condensation
nuclei for water vapor to form smog.
FUSIBLE PLUG: A device having a predetermined
melting temperature member for relief of
pressure.
GAGE (GAUGE)
(I) an instrument for measuring
pressure or liquid level; (2) also, an arbi—
trary scale of measurement for sheet metal
thickness, wire, and drill diameters.
GAS: A usually highly superheated vapor which,
within acceptable limits of accuracy, satis—
fies the perfect gag laws.
GAS, FLASH: The gas resulting from instantan—
eous evaporation of refrigerant in a pressure
reducing device to cool the refrigerant to
the evaporation temperature at a reduced
pressure .
GAS, FOUL:
GAS, INERT:
See gas, noncondensible.
A gas that neither experiences
nor causes chemical reaction nor undergoes
a change of state in a system or process;
nitrogen or helium mixed with a vol—
atile refrigerant.
GAS, NONCONDENSIBLE (FOUL GAS) :
Gas in a
refrigerating system which does not condense
at the temperature and partial pressure at
which it exists in the condenser, therefore
imposing a higher head pressure on the system.
GAS CONSTANT: The coefficient R in the perfect
gas equation pv equals RT.
GAS STORAGE: Artificial addition of carbon
dioxide to the atmosphere, particularly in
large concentration, with no attempt to reg—
ulate the amount of oxygen.
GENERATOR: Basic part of an absorption system.
A still provided with means of heating, used
to drive refrigerant out of solution.
GLASS, GAGE: Device for showing a liquid level .
GLASS, SIGHT: Glass tube used to indicate the
liquid level in tanks, bearings and similar
equipment .
GRADUATED ACTING: Term applied to a control
instrument or device which functions to give
throttling control; permitting operation
between full on and full off position.
GRAVITY, SPECIFIC:
Density compared to density
Of standard material; it usually refers to
water or to air.

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BASIC MATERIALS AND METHODS
SECTION 15050

HEAT EXCHANGER, HEAT PIPE: A bundle of
GRILLE; A louvered or perforated covering for
separate tubes each containing a two—
an air passage opening which can be located in
phase working fluid. A heat source at
the sidewall, ceiling, or floor .
one end evaporates the fluid, the gas is
then condensed by a heat sink at the
In flowing fluid, the
HEAD, DYNAMIC OR TOTAL:
other end. The liquid is returned by
sum of static and velocity pressures at the
gravity or by wick capillary action to
point of measurement.
the tube 's heated portion.
The static pressure of a fluid
HEAD, STATIC:
HEAT EXCHANGER, PLATE: Fixed plates which
expressed in terms of the height of a column
segment and keep separate the hot and cold
of the fluid, or of some manometric fluid, when
fluids .
it would support .
HEAT EXCHANGER, ROTARY: A cylindrical
HEAD, VELOCITY: In a moving fluid, the height of
wheel or drum packed with fluid conduct—
the fluid or of some manometric fluid equiva—
ing heat transfer medium which is rotated
lent to its velocity pressure .
through one fluid and then through a
counter—flowing second fluid.
HEAT; Form Of energy that is transferred by
virtue of a temperature difference.
HEAT EXCHANGER, RUN-AROUND: Finned tube
coils (closed system) or spray chambers
HEAT, HUMID: The ratio of increase of enthalpy
(open system) in which a liquid is cir-
per kg (pound) of dry air, with its associated
culated by gravity or pump action through
moisture, to the rise of temperature under con—
a heat source and then through a heat sink .
ditions of constant pressure and specific
Antifreeze may be used in the coil loop,
humidity .
and a desiccant, in the spray system.
Change of enthalpy during a change
HEAT, LATENT:
HEAT INTERCHANGER: see heat exchanger .
of state, usually expressed in j/ kg (Btu per
pound). With pure substances, latent heat is
HEAT, LATENT, OF CONDENSATION: Difference
absorbed or rejected at constant temperature
in specific enthalpy of a condensible
at any pressure .
fluid between its dry saturated vapor
state and its saturated liquid state
HEAT, LATENT, OP CONDENSATION OR EVAPORATION
at the same pressure.
Thermodynamically, di fference in
(SPECIFIC) :
the specific enthalpies of a pure condensible
HEAT OF FUSION: Latent involved in chang—
fluid between its dry saturated vapor state
ing between the solid and the liquid
and its saturated (not subcooled) liquid state
states .
at the same pressure.
HEAT OF REACTION: Heat per unit mass or
HEAT, SENSIBLE: Heat which is associated with a
per mole of reagents of products of re—
change in temperature; specific heat exchange
action in a chemical reaction; exother—
of temperature; in contrast to a heat inter—
mal if given off, endothermal if absorbed .
change of state (latent heat) occurs .
HEAT OF THE LIQUID: Enthalpy of a mass
HEAT, SPECIFIC: Ratio of the amount of heat
of liquid above an arbitrary zero .
required to raise the temperature Of a given
mass of any substance one degree to the quantity
HEAT PUMP, COOLING AND HEATING: A refrig-
required to raise the temperature of an equal
erating system designed to utilize
mass of a standard substance; usually water at
alternately or simultaneously the heat
15 degrees Centigrade (59 Fahrenheit) one degree.
extracted at a low temperature and the
heat rej ected at a higher temperature
HEAT, VITAL: Heat generated by fruits and veget—
for cooling and heating functions
able; in storage, due to ripening.
respectively.
HEAT CAPACITY: The amount of heat necessary to
HEAT PUMP, HEATING: A refrigerating system
raise the temperature of a given mass one degree.
designed primarily to utilize the heat
Numerically, the mass multiplied by the specific
rejection from the system for a desired
heat.
heating function .
HEAT CONDUCTOR ; A material capable of readily
HEAT REJECTION EFFECT, CONDENSING: That
conducting hteat; opposite of an insulator
portion of the total refrigerant heat
or insulation.
rejecting effect of a condenser which
is used for condensing the entering
HEAT EXCHANGER: A device specifically designed to
refrigerant vapor to a saturated liquid
transfer heat between two physically separated
at the entering refrigerant pressure .
fluids .

15050 - 16



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BASIC MATERIALS AND METHODS
SECTION 15050

HUMIDITY: Water vapor within a given space.
HEAT REJECTION EFFECT, SUBCOOLING: The total
refrigerant heat rejection effect less the
HUMIDITY, ABSOLUTE: The weight of water vapor
condensing heat rejection effect .
per unit volume.
HEAT REJECTION EFFECT, TOTAL REFRIGERANT:
HUMIDITY, PERCENTAGE: The ratio of the specific
The total useful capacity of a refrigerant
humidity of humid air to that of saturated
condenser for removing heat from the re—
air at the same temperature and pressure ,
frigerant circulated through it.
usually expressed as a percentage (degree
of saturation; saturation ratio) .
HEAT TRANSMISSION: Any time rate of heat
flow; usually refers to conduction, con—
HUMIDITY, RELATIVE: The ratio of the mole
vection, and radiation combined .
fraction of water vapor present in the
air to the mole fraction of water vapor
HEAT TRANSMISSION COEFFICIENT: Any one of
present in saturated air at the same temper—
a number of coefficients used in calcu—
ature and barometric pressure. Approximately ,
lating heat transmission by conduction,
it equals the ratio of the partial pressure
convection, and radiation, through
or density of the water vapor in the air to
various materials and structures .
the saturation pressure or density, respec—
tively, of water vapor at the same tempera—
HEATING, EFFECT COMPRESSOR (HEAT PUMP) :
The rate of heat delivery by the refrig—
ture .
erant assigned to the compressor in a
HUMIDITY RATIO (OR ALTERNATIVELY, THE MIXING
heat pump system. This is equal to the
The ratio of the mass of the water
product of the mass rate of refrigerant
RATIO) :
vapor to the mass of dry air contained in
flow produced by the compressor and the
difference in specific enthalpies of the
the sample .
refrigerant vapor at thermodynamic state
Is the mass of water vapor
HUMIDITY SPECIFIC:
leaving the compressor and saturated
to the total mass of the moist air sample.
liquid refrigerant at the pressure of
the vapor leaving the compressor .
HYDROMETER: An instrument which, by the extent
of its submergence, indicates the specific
HEATING, REGENERATIVE (OR COOLING) ;
Process
gravity of the liquid in which it floats .
of utilizing heat, which must be rejected
or absorbed in one part of the cycle, to
HYGROMETER: An instrument responsive to hum—
perform a useful function in another part
i ty condi tions (usually relative humidity)
of the cycle by heat transfer
of the atmosphere .
HIGH PRESSURE SIDE (HIGH SIDE) :
That por—
HYGROSCOPIC: Absorptive of moisture; readily
tion of a refrigerating system operating
absorbs and retains moisture .
at approximately the condenser pressure
In an evaporator, the ability
See humidistat.
HYGROSTAT :
HOLD-OVER :
to stay cold after heat removal from the
ICE BANK: A thermal accumulator in which ,
evaporator stops; a material used to store
during off—peak periods of refrigeration
heat in latent or sensible form.
demand, ice is formed, and during peak
HOOD DRAFT: A device installed on gas—fired
periods of refrigeration demand, compressor
capacity is supplemented by melting ice .
appliances designed to protect the appli—
ance from chimney draft disturbances .
ICE MAKER, CYCLIC: A cyclic-type automatic
ice maker has separate and sequential water
HORSEPOWER: Unit of power in the foot—pound—
fill, freezing and harvesting phases of the
second system; work done at the rate of
ice—making operation.
745.7W (550 feet pound per second) ,
ICE MAKER, NONCYCLIC: A noncyclic-type (con-
HOT GAS LINE: A line used to convey discharge
tinuous) , automatic ice maker has simultan—
gas from the compressor to the evaporator
eous water supply, freezing, and/or harvest—
for defrosting .
ing phases in the ice making operation.
HUMIDIFIER: A device to add moisture to air.
Temperature at which water freezes
ICE POINT:
under normal atmospheric pressure, 0 degrees
To add wat:er vapor to the atmos—
HUMIDIFY :
Centigrade (32 Fahrenheit) .
phere; to add water vapor or moisture to
any material.
ICE TRAY CAPACITY RATING: The weight of water
with the tray filled to within 3rrun (0.13 in.)
HUMIDISTAT : A regulatory device, actuated
of the top and with the grids in place .
by changes in humidity, used for automatic
control of relative humidity .

15050
- 17

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BASIC MATERIALS AND METHODS
SECTION 15050

ISOMER: One of a group of substances having
IGNITYON, INTERMITTENT: An igniter which burns
the same ultimate chemical composition but
during light off and while the main burner
different molecular structure.
is firing and which is shut off with the main
burner .
ISOTHERMAL: An adjective used to indicate a
change taking place at constant temperature .
IGNITION, INTERRUPTED: An igniter which burns
during light off and which is shut off (inter—
JACKETING: Surrounding by a confined bath
rupted) during normal operation of the main
or stream of fluid for temperature control
burner .
or heat absorption.
INCH OF WATER: A unit pressure equal to the
JOINT, BRAZED, HIGH-TEMPERATURE: A gas-tight
pressure exerted by a column of I—inch high
joint obtained by the joining of metal
liquid water at temperature of 4 degrees Centi—
parts with alloys which melt at tempera—
grade (39.2 Fahrenheit) .
Cures higher than 816 degrees centigrade
(1500 Fahrenheit) but. less than the melting
INDUCTION UNIT, ROOM AIR: A factory-made assem-
temperatures Of the joined parts .
bly consisting of a cooling coil (or cooling
and heating coil) and means for delivering
JOINT, BRAZED, LOW-TEMPERATURE: A gas-tight
preconditioned under pressure
joint obtained by the joining of metal
from an external source mixed with recircu—
parts with metallic mixtures or alloys
lated air by air—induction the
which melt at temperatures below 816
space being conditioned. This device is
degrees Centigrade (1500 Fahrenheit) but
normally designed for free delivery of air
above 538 degrees Centigrade (1000 Fahren—
into the space .
heit) .
INFILTRATION: Air flowing inward as through
JOINT, MECHANICAL: A gas-tight joint ob-
a wall and leakage of air not restrained.
tained by joining of metal parts through
a positive holding mechanical construction
Granulated, shredded, or
INSULATION, PILL:
(such as flanged joint, screwed joint ,
powdered material prepared from vegetable ,
flared joint) .
animal, or mineral origin.
JOINT, PITTSBURGH LOCK: Longitudinal joint
INSULATION, SOUND: Acoustical treatment of
used for rectangular sheet metal duct
fan housings, supply ducts, space enclosures ,
construction .
and other parts of system and equipment to
isolate vibration or to reduce noise trans—
JOINT, POCKET LOCK: Transferse joint used
mission.
in rectangular sheet metal duct construc—
INSULATION, THERMAL: A material having a
tion.
relatively high resistance to heat flow
JOINT, SLIP : A method of constructing trans—
and used principally to retard heat flow.
verse seams in rectangular sheet metal
INTERCOOLING: Removal of heat from compressed
ducts .
gas between compression stages .
JOINT, SNAPLOOK: Longitudinal joint used
for rectangular sheet metal duct construc—
INTERLOCKS, SAFETY: A device to prove the
tion in which the seam is "snapped" together .
physical state of a required condition and
to furnish that proof to the primary safety
JOINT, SOLDERED: A gas—tight joint obtained
control circuit.
by joining metal parts with metallic mix—
tures or alloys which melt at temperatures
IRRADIATION : Subjecting foods, and similar
not exceeding 430 degrees Centigrade (800
products to radiations of special wavelengths
Fahrenheit) and above 204 degrees Centi—
to kill certain bacteria; the amount of radiant
grade (400 Fahrenheit) .
energy incident on a surface per unit time and
unit area.
JOINT, STANDING SEAM: Joint used for trans-
verse joints in rectangular sheet metal
(I) prefix meaning constant: as
IS-, ISO
duct construction and for apparatus casing
isothermal, constant temperature; isentropic ,
constant entropy; isobaric, constant pressure;
seams .
and (2) in chemicals, one having different
JOINT, WELDED: A gas—tight joint obtained
characteristics but with the same number and
by joining of metal parts in the plastic
kind of atoms .
or molten state .
ISENTROPIC: An adjective describing a rever—
JOULE-THOMPSON EFFECT: The ratio of temper-
sible adiabatic process; a change taking
ature change to pressure change (dT/dp)
place at constant entropy .
of an actual gas in a process of thrott—
ling or expansion without working or inter—
ISOBARIC: An adjective used to indicate a change
changing heat
taking place at constant pressure .
18
15050 -

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SECTION 15050
- 19
LAG: Delay in action of the sensing ele—
ment of a control device due to the time
required for the sensing element to reach
equilibrium with the property being con—
trolled .
LAW OF PARTIAL PRESSURE, DALTON'S:
Each
constituent of a mixture of gases behaves
thermodynamically as if it alone occupied
the space. The sum of the individual
pressures of the constituents equals the
total pressure of the mixture .
LEVEL, NEUTRAL PRESSURE: Level at which
there is no pressure difference between
inside and outside a building under stack
effect .
The percentage increase in
LINEAR SWELL:
the length of a test specimen, usually
an elastomer, as a result of exposure
to refrigerants and/or oils.
LINER: The enclosure forming the interior
of the general refrigerated compartment
and/or some freezer compartment (s) .
LIQUEFACTION: A change of state to liquid;
generally used instead of condensation
in case of substances ordinarily gaseous.
LIQUID, VOLATILE: A liquid which evapor—
a tes readily at atmospheric pressure and
room temperatures .
LIQUID INDICATOR: device, frequently
combined with a strainer, located in the
liquid line and having a sight port by
which liquid flow may be observed for
the presence of bubbles .
LIQUID LINE: Tube or pipe carrying the
refrigerant liquid from the condenser
or receiver of a refrigerating system
to a pressure—reducing device.
LIQUID REFRIGERANT RECEIVER: A vessel in
a refrigerating system designed to in—
sure availability of adequate liquid
refrigerant for proper functioning of
the system and to store the liquid
refrigerant when the system is pumped
down.
LIQUOR: A solution used in absorption
refrigeration.
Solvent with rel—
LIQUOR, STRONG (RICH) :
atively high concentration of solute.
LIQUOR, WEAK: solvent with relatively
low concentration of solute.
The amount of heat
LOAD, REFRIGERATION:
per unit time imposed on a refriger—
ating system or the required rate of
heat removal .
15050
BASIC MATERIALS AND METHODS
LOAD, USAGE: The sum of the air change, product,
and miscellaneous loads on a refrigerator ;
the sum of the loads exclusive of wall heat
gains .
LOAD FACTOR: The ratio of actual mean load to
a maximum load of maximum production capacity
in a given period .
LOUVER: An assembly of sloping vanes intended
to permit air to pass through and can be
designed to inhibit transfer of water drop—
lets .
LOW-PRESSURE SIDE (LOW SIDE): That portion
of a refrigerating system operating at approx—
imately the evaporator pressure .
LYOPHILIZATION: The process of dehydrating a
frozen substance under conditions of subli—
mation; e.g., vacuum freeze—drying.
MACHINERY : The refrigerating equipment forming
a part of the refrigerating system including
any or all of the following:
compressor ,
condenser, generator, absorber (adsorber) ,
liquid receiver, connecting piping, and
evaporator .
MACHINERY, REFRIGERATING: The equipment com-
prising the refrigerating system including
its associated prime movers .
MAIN: Pipe or duct for distributing to or
collecting from various branches .
MANIFOLD: portion of main in which several
branches are close together. Also, single—
piece in which there are several fluid paths.
MANOMETER: An instrument for measuring pres—
sures; essentially a U—tube partially filled
with a liquid, usually water, mercury, or
a light oil, so constructed that the amount
of displacement of the liquid indicates the
pressure being exerted on the instrument.
See conductivity ,
MATERIAL, HOMOGENEOUS :
thermal .
MEDIA; The heat transfer material used in
rotary heat exchangers, also referred to as
matrix.
MELTING: Change of state from solid to liquid .
MELTING POINT: For a given pressure, the temper—
ature at which the solid and liquid phases
of the substance are in equilibrium.
METER: An instrument for measuring rates or
integrating rates over a period of time .
MIXTURE, EUTECTIC: A mixture which melts or
freezes normally at constant temperature and
Its melting point
with constant composition.
is usually the lowest possible for mixtures
of the given substances .

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SECTION 15050
MODULATING: Of a control, tending to adjust by
OZONE :
increments and decrements; also one modified
by variation of a second condi tion.
The amount of substance of a system
MOLE (MOL) :
that contains as many elementary enti ties as
the number of atoms in O .012 kilogram of car—
bon—12.
MOLECULAR, SIEVE: An adsorbent composed of
porous aluminosilicates with pores of uniform
molecular dimensions which selectively adsorb
molecules of the substance to be gathered .
MOTIVE POWER: Used to express the source from
which a device obtains its power (electric
or fluid) .
MOTOR, AIR: An air—operated device which is
used primarily for opening or closing dampers.
MOTOR, CAPACITOR: A single-phase induction
motor with a main winding arranged for direct
connection to a source of power and an auxil—
iary winding connected in series with a capac—
i tor .
NOZZLE, RETURN FLOW: A mechanical atomizing oil
burner in which part of the oil supplied to
the atomizer is withdrawn and returned to
storage or the oil line supplying the atomizer .
OIL DISTILLATE: Light fraction of oil, separated
from crude oil by fractional distillation .
OIL, RESIDUAL: Products remaining from crude
petroleum by removing some of the water and
an appreciable percentage of the more vola—
tile hydrocarbons .
OIL SEPARATOR: A device for separating oil and
oil vapor from the refrigerant, usually
installed in the compressor discharge line.
OIL STILL: A device to separate Oil from refrig—
erant by a distillation process .
ORGANIC COMPOUND: Originally a chemical com—
pound produced by a life process Now gen—
erally understood to include all compounds
containing carbon.
See diffuser, air.
OUTLET, CEILING:
OUTLET, SLOTTED: A long, narrow air distri-
but ion outlet, comprised of deflecting members ,
located in the ceiling, sidewall, or sill,
with an aspect ratio greater than 10, designed
to distribute supply air in varing directions
and planes, and arranged to promote mixing of
pr imary air and secondary room air .
OUTLET, VANED: A register, or grill, equipped
with vertical and/or horizontal adjustable
vanes .
OUTPUT: Capacity; duty, performance; net refrig—
eration produced by a system.
15050
- 20
BASIC MATERIALS AND METHODS
Triatomic oxygen (OR) sometimes
used in air conditioning ör cold storage
as an odor eliminator; can be toxic in
certain concentrations .
PACKING: see stuffing box.
PERFORMANCE FACTOR: The ratio of the useful
output capacity of a system to the input
Units of capacity
required to obtain it .
and input need not be consistent.
PERMEABILITY : Water vapor permeability is
a property of a substance which permits
passage of water vapor, and equals per—
meance of a 1 inch thickness of the sub—
stance. When permeability varies with
psychrometric conditions, the "spot tt or
i' specific permeability " defines the prop—
erty at a specific condition. permeability
is measured in perm-inches .
In thermodynamics, one of the states
PHASE:
of matter, as solid, liquid, or gaseous .
The volume genera ted
PLAQUE AND/OR SUMP :
by embossed areas on the interior sur—
faces of the general refrigerated and
freezer compartment (s) .
PLUMBING-PLUMBING SYSTEM: Works that
include the water supply and distribution
pipes, plumbing fixtures and traps; soil,
waste and vent pipes; sanitary and storm
drains and building sewers, including
their respective connections, devices and
appurtenances to an approved point of
See Section 15400 Plumbing
disposal .
for exclusive expanse of defini tions .
POINT, CRITICAL: Of a substance, state
point at which liquid and vapor have
identical properties; critical tempera—
ture, critical pressure, and critical
volume are the terms given to the temp—
erature, pressure, and volume at the
critical point. Above the critical
temperature or pressure, there is no
demarcation line between liquid and
gaseous phases .
POINT, TRIPLE: State point at which three
solid,
phases of a given substance (i . e.
liquid, and gas) exist in equilibrium.
POLYTROPIC CHANGE: Any set of changes in
vn
a gas represented by the equation, P
equals constant.
POND, SPRAY : Arrangement for lowering the
temperature of water in contact wi th
outside air by evaporative cooling of
The water to be cooled is
the water .
sprayed by nozzles into the space above
a body of previously cooled water and
allowed to fall by gravity into it.

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SECTION 15050
BASIC MATERIALS AND METHODS
POWER: The rate of performing work; c onu•non
PRESSURE SUCTION: An operating pressure in a
units are watt (horsepower and Btuh) ,
refrigerating system measured in the suction
line at the compressor inlet .
POWER CONSUMPTION: The power used, multi-
plied by time, measured in watt (hp/hr)
PRESSURE TOTAL: The sum of the static pressure
and the velocity pressure at the point of
PRECIPITATOR, ELECTRIC: A device for remov-
meas
ing dust from the air by means of electric
charges induced on the dust particles.
PRESSURE, VAPOR: The pressure exerted by the
molecules at a given vapor
PRECOOLER :
( 1) A cooler for removing sens—
i ble heat before shipping, storing, or
PRESSURE, VELOCITY:
In a moving fluid, the
processing; (2) a device for cooling a
pressure capable of causing an equivalent
fluid before it enters some piece of
velocity, if applied to move the same fluid
apparatus
through an orifice, such that all pressure
energy expended is converted into kinetic
PREHEATING :
In air conditioning, to heat
energy .
the air ahead of other processes .
PRESSURE CHANGE OF AN EXPANSION VALVE: The
PRESSURE: The normal force exerted by a
change in outlet pressure of a constant
homogeneous liguid or gas, per unit of
pressure expansion valve required to open
area, on the wall of the container .
the valve a predetermined amount.
PRESSURE, ABSOLUTE:
Pressure referred to
PRESSURE DROP:
Static pressure loss in fluid
a perfect vacuum.
It is the sum of gage
pressure, as from one end of duct to the
pressure and atmospheric pressure .
other, due to friction.
PRESSURE, CRITICAL: vapor pressure corres-
PRESSURE EQUALIZING: Allowing high- and low-
ponding to the substance's critical state
side pressures to equalize or nearly equalize
at which the liquid and vapor have iden—
during idle periods as by use of an unload—
tical properties .
ing valve or by a vapor lock liquid control,
or nearly equalizing inlet and discharge
PRESSURE, DISCHARGE: An operating pressure
pressures on the compressors .
In either
in a refrigerating system measured in
case, to reduce starting torque load.
the discharge line at the compressor out—
let.
PRESSURE-IMPOSING ELEMENT: Any device or
portion of the equipment used for increasing
PRESSURE, DYNAMIC: The pressure of a fluid
the pressure on the refrigerant.
resulting from its motion.
PRESSURE-LIMITING DEVICE: A pressure-actuated
PRESSURE, GAGE:
Pressure above atmospheric .
mechanism designed to automatically stop
the operation of a compressor or other
PRESSURE, HYDROSTATIC;
The normal force per
pressure—producing component at a predeter—
unit area that would be exerted by a moving
mined maximum or minimum pressure.
fluid on an infinitesimally small body
immersed in it if the body were carried
PRESSURE RELIEF DEVICE: A valve or rupture
aldng with the fluid.
member designed to relieve excessive pressure
automa tically .
PRESSURE, OPERATING: The pressure occurring
at a reference point in a refrigerating
PRESSURE VESSEL: Any refrigerant—containing
system when the system is in operation.
receptacle of a refrigerating system, other
than evaporators (each separat section of
PRESSURE, PARTIAL:
portion of total gas
which does not exceed O .5 feet of refrig—
pressure of a mixture attributable to one
erant—containing volume) , evaporator coils,
component .
compressors, condenser coils, controls ,
headers, and piping.
PRESSURE, SATURATION: The saturation pressure
for a pure substance for any given temper—
PROPERTIES, THERMODYNAMIC:
Basic qualities
ature is that pressure at which vapor and
used in defining the condi tion of a sub—
liquid, or vapor and solid, can coexist
stance, such as temperature, pressure, vol—
in stable equilibrium.
ume, enthalpy, entropy .
PRESSURE, STATIC:
( I) The pressure with
PSYCHROMETER; Instrument for measuring relative
respect to a stationary surface tangent
humidities by means of wet— and dry—bulb
to the mass flow velocity vector;
(2) the
temperatures .
pressure with respect to a surface at
rest in relation to the surrounding fluid.
15050
- 21

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SECTION 15050
PSYCHROMETRY :
The branch of physics relating to
the measurement or determination of atmospheric
conditions, particularly regarding the moisture
mixed with the air .
PURGER (AIR V ENT): A device for removing noncon—
densable gas from refrigerant condensers, for
removing low—concentration liquor from absorp—
tion system evaporators, or air from hot water
or steam systems .
PYROMETER: An instrument for measuring high temp—
era ture.
QUALITY OF WET VAPOR: Fraction by weight of vapor
in a mixture of liquid and vapor.
RADIATION, THERMAL:
Transmission of heat through
space by wave motion; passage Of heat from one
Object to another wi thout warming the space be—
tween .
RECTIFIER: In refrigeration, an externally
cooled heat exchanger in the high side of an
absorption system for condensing absorbent
and separating it from the refrigerant before
passing it to the condenser.
REDUCER, PRESSURE, LIQUID REFRIGERANT: A device
or devices, in a refrigerating system, in which
the pressure of the fluid is reduced from that
Of condensed liquid to that Of the evaporator .
RE-EXPANSION LINE: The curve on an indicator
card, representing the pressure; the total
volume relationship of clearance fluid during
the initial portion of the return stroke of
the piston prior to the suction valve's open—
ing.
REFRIGERANT: The fluid used for heat transfer
in a refrigerating system, which absorbs heat
at a low temperature and a low pressure of
the fluid and rejects heat at a higher temp—
erature and a higher pressure of the fluid,
usually involving changes of State of the
fluid.
REFRIGERANT, FLAMMABLE: Any refrigerant which
burns when mixed with air, e.g., ethylchlor—
ide, methylchloride, and the hydrocarbons.
REFRIGERANT, SECONDARY: Any volatile or non-
volatile substance in an indirect refriger—
at ing system that absorbs heat from a sub—
stance or space to be refrigerated and
rejects this heat to the evaporator of the
refrigerating system.
REFRIGERANT CHARGE:
The designated amount of
refrigerant required for proper functioning
of a closed refrigerating system.
REFRIGERATING COMPRESSOR PERFORMANCE FACTOR:
The ratio Of its capacity to its power input .
15050
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BASIC MATERIALS AND METHODS
REFRIGERATING EFFECT, COMPRESSOR: The
rate of heat removal by the refrigerant
assigned to the compressor in a refrig—
erating system. This is equal to the
product of the mass rate of refrigerant
flow produced by the compressor and the
difference in specific enthalpies of the
refrigerant vapor at its thermodynamic
state entering the compressor and refrig—
erant liquid at saturation temperature
corresponding to the pressure of the
vapor leaving the compressor .
REFRIGERATING EFFECT, CONDENSING UNIT: The
rate of heat removal by the refrigerant
assigned to the condensing unit in a
refrigerating system. This is equal to
the product of the mass rate of refrig—
erant flow produced by the condensing
unit and the difference in the specific
enthalpies of the refrigerant vapor
entering the unit and the refrigerant
liguid leaving the unit.
REFRIGERATING EFFECT, NET WATER (BRINE)
COOLER :
The product of the weight rate
of water or brine flow and the differ—
ence in enthalpy of the entering and
leaving water or brine expressed in
heat units per unit Of time.
It is
expressed also by the total refriger—
at ion effect less the heat leakage
losses .
REFRIGERATING EFFECT, SUBCOOLING: The
additional refrigeration effect made
available by subcooling the refriger—
ant liquid in the condenser .
REFRIGERATING EFFECT, TOTAL, WATER (BRINE)
COOLER :
The product Of the weight rate
of refrigerant flow and the difference
in enthalpy of the entering and leaving
refrigerant fluid, expressed in heat
units per unit of time .
REFRIGERATING MEDIUM: Any substance whose
temperature is such that it is used,
with or without a change Of state, to
lower the temperature of other bodies
or substances below the ambient temper—
ature .
REFRIGERATING SYSTEM PERFORMANCE FACTOR:
The ratio of the useful refrigerating
effect of the system to the power input.
REFRIGERATION
See system ,
REFRIGERATION
See system,
(COOLING) ,
direct .
(COOLING) ,
indirect .
DIRECT METHOD OF:
INDIRECT METHOD OF :

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SECTION 15050
Service to a group
REFRIGERATION, PIPE LINE:
of buildings with a refrigerant supply from
a central refrigerating plant.
REGAIN: Of moisture, the amount absorbed by
any material in percent of weight of that
material .
REGISTER: A combination grill and damper
assembly covering an air opening.
REGULATION: Refreezing of water that resul—
ted from melting of ice under pressure
Refrigeration is not required.
REGULATOR, DmFT: A device sometimes in-
stalled in the breeching between a fired
appliance and the chimney; it is intended
to control chimney draft effect on induc—
ing gas flow through the appliance.
RESISTANCE, THERMAL; The reciprocal of
conductance thermal .
RESISTIVITY, ELECTRICAL, VOLUME: The elec-
trical resistance of a substance contained
between flat, parallel electrodes multi—
plied by the area of the electrodes and
divided by the electrode gap .
RESISTIVITY, THERMAL: The reciprocal of
conductivi ty, thermal .
Production of carbon dioxide
RESPIRATION :
and heat by ripening of perishables in
storage; also the breathing process of
animals .
RETURN, DRY: A return pipe in a steam heat—
ing system which carries both water of
condensation and air.
It is always above
the level of the water line in the boi ler
in a gravity system. (Also see return,
wet)
RETURN, WET: That part of a return main Of
a steam heating system which is filled
with water of condensation.
It usually
is below the level of the water line in the
boiler, although not necessarily so. (Also
see return, dry) .
RUPTURE, MEMBER: A device which automatically
ruptures at a predetermined pressure .
SAFETY HEAD: In a compressor, a cylinder
head held in place by a spring of such
strength that, during normal operation, it
will not be compressed but moved by solid
or liquid matter or abnormal gas pressure
between this and the piston; thus, pro—
tecting the compressor.
SALINOMETER: Hydrometer calibrated in salt
concen tr a tion .
15050
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BASIC MATERIALS AND METHODS
SAPONIFY: To turn to soap, as oil contacting
an alkali or alkaline refrigerant. Chem—
icaIIy, to cause an ester to react with an
inorganic base, the products being an alco—
hol and an acid (either free or in the form
By extension, to hydrolyze
of a salt) .
compounds other than esters .
SATURATION: The condition for coexistence in
stable equilibrim of a vapor and liquid or
a vapor and solid phase of the same sub—
stance. As an example, steam over the water
from which it is being generated.
SATURATION, DEGREE OF (SATURATION RATIO): The
ratio of the specific humidity Of humid air
to that of saturated air at the same temper—
ature and pressure, usually expressed as a
percentage .
SEAL, BELLOWS: Metal bellows, used in a shaft
seal or in place of a packing for valves;
also used in long pipe lines instead of
gaskets to compensate for expansion of the
line with temperature .
SEAL, SHAFT : A rubbing seal or stuffing box
used to prevent fluid leakage between the
shaft and bearing of a compressor or other
fluid—moving device.
SENSIBLE HEAT RATIO, AIR COOLER: The ratio
of sensible cooling effect to total cooling
effect of an air cooler.
SHELL AND TUBE: Pertaining to heat exchangers
in which a nest of tubes or pipes, or a
coil of tube or pipe, is contained in a
shell or container. The pipe (or pipes)
carries a fluid through it, while the shell
is also provided with an inlet and outlet
for fluid flow.
SHELL-TYPE APPARATUS: A refrigerant-contain-
ing pressure vessel having tubes for the
passage of a refrigerating fluid or one to
be cooled .
SILICA GEL: A form of silicon dioxide which
adsorbs moisture readily and is used as a
drying agent.
SLUDGE ; A product of decomposition of oil
resulting from impurities, moisture, or
chemical reactions, and favored by excessive
Sludge may be mushy, guruny ,
temperature .
or hard.
SOLAR CONSTANT: The solar radiation inten—
sity incident on a surface normal to the
sun 's rays outside the earth 's atmosphere
at a distance from the sun equal to the
mean distance between the earth and the sun.
SOLUTION, EUTECTIC: mixture which melts
or freezes, normally at constant temperature
and with constant composition .
Its melting
point is usually the lowest possible for
mixtures of the given substances.

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SECTION 15050
BASIC MATERIALS AND METHODS
SORPTION: Adsorption or absorption .
SUCTION LINE: The tube or pipe which car—
ries the refrigerant vapor from the evap—
SPRAY DECK: An overhead bunker where air is
orator to the compressor inlet.
cooled and circulated by brine sprays .
SUN EFFECT: Solar energy transmi teed into
SPRAY-TYPE AIR COOLER: A forced-circulation air
interior spaces through windows and build—
cooler, where the coil surface capacity is aug—
ing materials.
mented by a liquid spray during operation .
SUPERHEAT, (SPECIFIC) :
Difference in spec—
STANDARD RATING: A rating based on tests per—
i fic enthalpies of a pure condensible
formed at Standard Rating Conditions .
fluid between vapor at a given tempera—
ture above saturation and vapor at the
Rating conditions
STANDARD RATING CONDITIONS:
dry saturated state at the same pressure .
used as the basis for comparing performance
characteristics.
SUPERHEATER: A heat exchanger used on
flooded evaporators, where hot liquid
STATE, GASEOUS: One of three states of matter
on its way to enter the evaporator is
characterized by the greatest freedom of
cooled by supplying heat to dry and super—
molecules and lack of any inherent fixed
heat the wet vapor leaving the evaporator .
shape or volume .
SURFACE COOLING:
See cooling, surface.
STATE, LIQUID:
One Of three states Of matter
characterized by limited freedom of molecules
SURFACE, HEATING: The exterior surface of
and by substantial imcompressibility .
a heating unit. Extended heating sur—
face (or extended surface) , consisting
STATE, SOLID: One of three states or phases of
of fins, pins, or ribs which receive heat
matter, characterized by stability of dimen—
by conduction from the prime surface .
sions, relative incompressibili ty, and mole—
Prime surface: heating surface having
cular motion held to limited oscillation .
the heating medium on one side and air
(or extended surface) on the other .
STEAM, DRY SATURATED:
Steam at the saturation
temperature corresponding to the pressure
SURGE DRUM: see accumulator.
and containing no water in suspension.
SWEATING: Condensation of moisture from air
STEAM, SUPERHEATED: Steam at a temperature
on a surface which is below the dew—point
higher than the saturation temperature corres—
temperat ure .
ponding to the pressure.
SWITCH, FLOAT: A device in which a float
STEAM, WET SATURATED;
Steam at the saturation
ball, through variation on the level of
temperature corresponding to the pressure
liquid, operates one or more sets of elec—
and containing water particles in suspen—
trical contacts to activiate or deactivate
Sion .
other controls or alarms .
Of piston, the length of travel (twice
STROKE :
SYSTEM: A heating or refrigerating scheme
its crank radius) .
or machine usually confined to those parts
contacting heating or refrigerating medium.
STUFFING BOX : A packing g land s urrounding a
shaft, stem, or rod to prevent leakage.
SYSTEM, ABSORPTION: A refrigerating system
in which the refrigerant gas evolved in
SUBCOOLING: Process of cooling refrigerant
the evaporator is taken up in an absorber
below condensing temperature for a given
and released in a generator on heat appli—
pressure; also, cooling a liquid below its
ca tion.
freezing point where it can exist only in a
state of unstable equilibrium.
SYSTEM, AIR AGITATION: A combination con-
sisting Of a power—driven blower, distri—
SUBCOOLING, HEAT OF (SPECIFIC) :
Difference in
but ing piping, and flexibly connected
specific enthalpies of a pure condensable
fittings for delivering air to the water
fluid between the saturated (not subcooled)
in ice cans to agitate the water and pro—
liquid state and the cooled liquid at a given
mote production of clear ice .
temperature below its condensation temper—
a ture at the same pressure .
SYSTEM, BRINE SPRAY: A refrigerating scheme
for cooling by a mist or spray of brine.
SUBLIMATION: A change of state directly from
solid to gas without appearance of liquid.
SYSTEM, CASCADE: one having two or more
refrigerating circuts, each with a pres—
SUCTION INLET: The port through which as enters.
sure imposing element, condenser, and
evaporator, where the evaporator of one
circuit cools the condenser of another
(lower temperature) circuit.
15050
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SECTION 15050
SYSTEM, CENTRAL FAN: A mechanical indirect
system of heating, ventilating, or air con—
ditioning, in which the air is treated or
handled by equipment located outside the
rooms served, usually at a central location,
and conveyed to and from the rooms by a fan
and a system of distributing ducts.
SYSTEM, CENTRAL PLANT: A system with two or
more low sides connected to a single, central
high side; a multiple system.
SYSTEM, CLOSED: A heating or refrigerating
piping system in which circulating water
or brine is completed enclosed, under pres—
sure above atmospheric, and shut off from
the atmosphere except for an expansion tank .
SYSTEM, COMMERCIAL: A heating, cooling or
refrigerating sys tem used in a commercial
and/or a business place, such as meat
market, store, florist shop, hotel, office
building, restaurant, candy shop, bakery ,
or other place of similar commercial enter—
price, assembled and installed in the manu—
facturing and business portion of any build—
ing .
In household refrig—
SYSTEM, CYCLE DEFROST:
era tors and combination refrigerator—
freezers only, a system in which refrig—
erated surfaces of the general refrigerated
compartment are defrosted by an automatic
defrost system.
SYSTEM, DENSE AIR: A cold air system main-
tained under pressure greater than atmos—
pheric in which air is compressed, heat of
compression dissipated, and the air, chilled
by expansion and performance of work, can
create useful refrigeration
SYSTEM, DIRECT: A heating, air—conditioning ,
or refrigerating system in which electric
heating elements or products of combustion,
or the refrigerant, exchange heat directly
with the material or space heated or cooled ,
or with the air in a passageway cortununi—
cating with such space.
SYSTEM, DIRECT EXPANSION: A refrigerating
system in which the evaporator is in direct
contact with refrigerated material or space,
or is located in air circulating passages
communicating with such space .
SYSTEM, DOWN—FEED: A piping arrangement for
a heating, air—conditioning or refrigerating
system, in which heating or cooling fluid
is circulated through supply mains which
are above the levels of the heating or
cooling units which they serve .
SYSTEM, DUAL TEMPERATURE BRINE: In chilling
beef, the use of an initial brine tempera—
ture, followed by a lower brine temperature .
15050
BASIC MATERIALS AND METHODS
SYSTEM, DUCT: A series of ducts, elbows, and
connectors to convey air from one location
to another.
SYSTEM, FLOODED: A system in which only part
of the refrigerant passing over the heat
transfer surface is evaporated, and the por—
tion not evaporated is separated from the
vapor and recirculated .
SYSTEM FORCED CIRCULATION: heating, air-
conditioning or refrigerating system in
which heating or cooling fluid is circu—
lated by a fan or pump.
SYSTEM, GRAVITY CIRCULATION: A heating or
refrigerating system in which heating or
cooling fluid is circulated by the motive
head due to the difference in densities
of cooler and warmer fluids in two sides
of the system.
SYSTEM, INDIRECT: A heating, air-condition-
ing or refrigerating system in which a fluid,
such as air (water or brine, heated or
cooled by electric heating elements or products
of combustion or by a refrigerant) is circu—
lated to the material or space to be heated
or cooled, or is used to heat or cool air
so circulated.
SYSTEM, INDUSTRIAL: A system used in the manu-
facture or processing of materials, such
as ice—making plants, cold storage ware—
houses, ice cream plants, dairy plants, pack—
ing houses, chemical plants, and other places
of similar industrial enterprise .
In air conditioning ,
SYSTEM, LOW PRESSURE:
a distributing system delivering air to
ordinary ventilating grills at low veloc—
ities with static losses through the supply
grills.
SYSTEM, MULTIPLE: A system using the direct
method in which refrigerant is delivered
to two or more evaporators in separate rooms
or refrigerators .
SYSTEM, NO-FROST: A system in which all refrig-
erated surfaces in the cabinet are defrosted
by an automatic defrost system.
SYSTEM, OFF—PEAK: A system with control which
normally avoids use of power during peak
load periods, usually having eutectic or
water—ice hold—over means.
SYSTEM, ONE-PIPE: A piping system in which
the fluid withdrawn from the supply main
passes through a heating or cooling unit
and returns to the same supply main.
SYSTEM, OPEN: A heating or refrigerating
piping system in which circulating water
or brine return main is connected to an
open—vented elevated tank which serves as
a reservoir to accommodate expansion and
contraction of the fluid, and as an inspec—
don point for the fluid's condition.
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SECTION 15050
SYSTEM, OVERHEAD: A heating, air-conditioning
or refrigerating piping system in which the
supply main is above the heating or cooling
units supplied.
SYSTEM, REFRIGERATING: Any system which, in
operation between a heat source and a heat
sink (in the thermodynamic sense) at two dif—
ferent temperatures, can absorb heat from
the heat source at the lower temperature
and reject heat to the heat sink at the higher
temper at ure.
SYSTEM, REFRIGERATING, ABSORPTION-TYPE: A
refrigerating system in which refrigeration
is effected by evaporating a refrigerant in
a heat exchanger (evaporator) , resulting
vapor then being absorbed by an absorbent
medium from which it is subsequently expelled
by heating at a higher partial vapor pressure
and condensed by cooling in another heat
exchanger (condenser) .
SYSTEM, REFRIGERATING, COMPRESSION-TYPE; A
refrigerating system in which the temperature
and pressure of gaseous refrigerant are in—
creased by a mechanically operated component .
In most cases, the refrigerant undergoes
changes of state in the system.
SYSTEM, REMOVABLE UNIT: A refrigerating system,
readily removable as one unit from the cab—
inet or space which it cools and from the build—
ing in which it is used wi thout disconnecting
any refrigerant containing part of the system.
SYSTEM, RUN-AROUND: A regenerative-type closed
secondary system in which a continuously cir—
culated fluid abstracts heat from the primary
system fluid at one place, returning this
heat to the primary system fluid at another
place .
SYSTEM, SELF-CONTAINED (SINGLE PACKAGED) REFRIG-
ERATING: A completely factory—assembled and
tested refrigerating system in a suitable
frame or enclosure, in which all refrigerant—
containing parts are permanently connected at
the factory.
SYSTEM, STEAM JET: A refrigerating system in
which high pressure steam, supplied through
a nozzle and acting to eject vapor from the
evaporator, maintains the requisite low pres—
sure on one side and produces a high pressure
on the other by virtue of compression in a
following diffusion passage.
SYSTEM, TWO—PIPE: A piping system in which the
fluid withdrawn from the supply can passes
through a heating or cooling unit to a separ—
ate return main.
SYSTEM, UNITARY REFRIGERATING: A complete fac-
tory—assembled and tested refrigerating system
comprising one or more assemblies which may
be shipped as one unit or separately but which
are designed to be used together .
15050
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BASIC MATERIALS AND METHODS
SYSTEM, UPFEED: A piping arrangement for
a heating, air—conditioning, or refrig—
erating system, in which cooling fluid
is circulated through supply mains which
are below the levels of heating or cooling
units they serve .
SYSTEM, VAPOR: A refrigerating system
employing a condensable vapor as the
refrigerant.
SYSTEM, WATER VACUUM: In refrigeration,
one which employs a vacuum to boil water
at the temperature desired; one which
employs evaporating water vapor as the
refrigerant .
SYSTEM, YEAR-ROUND AIR-CONDITIONING: An
air—conditioning system which ventilates ,
heats, and humidifies in winter, cools
and dehumidifies in summer the spaces
under consideration, and provides the
desired degrees of air motion and clean—
liness.
TANK, BRINE: (I) In ice plant, main freez—
ing tank, in which cans are irnmersed
while ice is being produced; (2) in
brine—circulating system, a storage or
balance tank for brine; (3) in domestic
and commercial fields, a container sur—
rounding the evaporator and filled with
brine for storing refrigerant or equal—
i zing temperature at various points of
the evaporator, especially in ice—cream
cabinets .
TANK, BRINE RETURN: A reservoir in an open
circulating brine system for storing
brine at the pump suction and for inspect—
ing condition and flow of brine .
TANK, ICE-MAKING: A tank arranged with
proper accessories to hold an evaporator
and antifreeze solution and ice cans, the
cans being immersed in the solution which
usually is in circulation around the evap—
orator and cans .
TEMPERATURE: The thermal state of matter
with reference to its tendency to commun—
icate heat to matter in contact with it.
TEMPERATURE, ABSOLUTE:
Temperature expressed
in degrees kelvin.
TEMPERATURE, CRITICAL:
The saturation temper—
ature corresponding to the critical state
of the substance at which the properties
of the liquid and vapor are identical.
TEMPERATURE, ABSOLUTE ZERO: The zero point
on the kelvin temperature scale ,
-273.16
degrees Centigrade (—459.69 Fahrenheit) .
TEMPERATURE, COLOR:
The temperature of a
perfect radiator (blackbody) that would
emit the same relative intensity at two
Wavelengths (usual Iy red and green lights)
as the relative intensity radiated by the
subject surface.

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SECTION 15050
TEMPERATURE ,
erature.
TEMPERATURE ,
DEW-POINT :
DRY-BULB :
See dew—point temp—
The temperature of a
gas or mixture
of gases indica ted by an
accurate thermometer after correction for
radiation .
TEMPERATURE, EFFECTIVE: The dry-bulb temp-
erature of a black enclosure at relative
humidity (sea level) , in which a solid body
or occupant would exchange the same heat
by radiation, convection, and evaporation
as in the existing nonuniform environment .
TEMPERATURE, MEAN RADIANT (MRT) :
The temper—
a ture of a uniform black enclosure in which
a solid body or occupant would exchange the
same amount of radiant heat as in the exist—
ing nonuni form environment.
TEMPERATURE, ROOM: The temperature of any
(l) a room in which a refrig-
room, e.g.:
erator is being operated or tested; (2)
a room being condi tioned for the occupant 's
comfort. Room temperature used colloquially
to mean the ordinary temperature one is
accustomed to find in dwellings .
TEMPERATURE, SATURATION: Of a fluid, the
boiling point corresponding to a given
pressure; evaporation temperature, conden—
sat ion temperature .
TEMPERATURE, WET-BULB : Thermodynamic wet-
bult temperature is the temperature at
which liquid or solid water, by evapora—
ting into air can bring the air to satur—
ation adiabatically at the same temper—
a ture . Wet—bulb temperature (wi thout
qualification) is the temperature indi—
cated by a wet—bulb psychrometer con—
structed and used according to speci—
f ica tions .
TEMPERATURE, WET-BULB DEPRESSION: Differ-
ence between dry—bulb and wet—bulb tem—
peratures .
TEMPERATURE DIFFERENCE, DIFFUSION: Tem-
perature dif ference between the air tern—
perature at supply opening and design
outdoor temperature.
TEMPERATURE DIFFERENCE, EFFECTIVE; Differ-
ence between the room air temperature and
the supply air temperature at the outlet
to the room.
TEMPERATURE DIFFERENCE, MEAN: Mean of dif-
ference between temperatures of a fluid
receiving and a fluid yielding heat.
TEMPERATURE, LOW: Temperature below ordin—
ary refrigerating plant requirements;
e.g., from —34 .4 degrees Centigrade (—30
Fahrenheit) down; also, any part of a
system below another parallel refriger—
ating level of temperature.
15050
BASIC MATERIALS AND METHODS
THAW NEEDLE : A small tube with valved head,
connected by hose to a source of warm water
or steam, which may be inserted in the air
agitation tube in an ice can for the purpose
of thawing the air agitation tube loose from
the ice block.
THERMOCOUPLE: A device for measuring temper—
ature, utilizing the fact that an electro—
motive force is generated whenever two junc—
tions of two dissimilar metals in an elec—
tric circuit are at different temperature
levels .
THERMODYNAMICS; The science of heat energy
and its transformation to and from other
forms of energy .
THERMOMETER : An instrument for measuring
temperature .
THERMOSTAT : An automatic control device
actuated by temperature and designed to
be responsive to temperature .
THERMOSTAT, DIRECT-ACTING: An instrument for
activating a control circuit on sensing a
predetermined low temperature .
THERMOSTAT, REVERSE-ACTING: An instrument
for activating a control circuit on sensing
a predetermined high temperature .
THROTTLING: Of a fluid, an irreversible
adiabatic process which consists of lower—
ing pressure of an expansion without work .
THROW: The horizontal or vertical axial
distance an air stream travels after leav—
ing an air outlet before the maximum stream
velocity is reduced to a specified terminal
level .
TON OF REFRIGERATION: A useful refrigerating
effect equal to 3516 watts (12, 000 Btuh) .
TON-DAY OF REFRIGERATION: The heat removed
by a ton of refrigeration operating for a
day
TONS ,
in
TONS ,
in
TONS ,
in
DRY: The sensible heat load expressed
tons of refrigeration.
MOISTURE: Latent heat load expressed
tons of refrigeration.
TOTAL: The total heat load expressed
tons of refrigeration; the surn of the
dry tons and the moisture tons .
TOTAL HEAT:
See enthalpy .
TOWER, WATER-COOLING; An enclosed device
for evaporatively cooling water by contact
with air.
TOWER, WATER-COOLING, FORCED-DRAFT: A mechan-
ical draft water—cooling tower having one
or more fans located in the air entering
the tower .
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TOWER, WATER-COOLING, INDUCED-DRAFT: A mechan-
icaI draft water—cooling tower having one or
more fans located in the air leaving the tower.
TOWER, WATER-COOLING, MECHANICAL-DRAFT: A water-
cooling tower utilizing one or more fans to move
the air through the tower, the fans being an
integral part of the tower.
In thermodynamics, a general term
TRANSMISSION :
for heat travel; properly, heat transferred
per unit of time.
TRANSMITTANCE, THERMAL (U factor) :
The time rate
of heat flow per unit area under steady condi—
tions from the fluid on the warm side of a
barrier to the fluid on the cold side, per
unit temperature difference between the two
fluids .
TRAP, STEAM: A device for allowing the passage
of condensate, or air and condensate, and
preventing the passage of steam.
TUBE, CAPILLARY :
In refrigeration practice,
a tube of small internal diameter used as a
liquid refrigerant flow control or expansion
device between high and low sides; also used
to transmit pressure from the sensitive bulb
of some temperature controls to the operating
elemen t.
UNLOADER: A device on or in a compressor for
equalizing the high— and low—side pressures
for a brief period during starting in order
to decrease the starting load on the motor;
also a device for controlling compressor
capacity by rendering one or more cylinders
ineffective.
VALVE, BACK PRESSURE (EVAPORATOR PRESSURE
REGULATOR) : An automatic valve loca ted between
the evaporator outlet and compressor inlet
that is responsive to its own inlet pressure
or to the vapor flow when necessary to pre—
vent the evaporator pressure from falling
below a selected value .
VALVE, CHARGING: A valve used to charge or
add refrigerant to the system or add oil to
the compressor crankcase.
VALVE, CHECK: valve allowing fluid flow in
one direction only.
VALVE, CONSTANT PRESSURE EXPANSION: see valve,
expansion.
VALVE, DIAPHRAGM: A form or pack less valve,
manually or mechanically actuated; also a
valve actuated by pressure of a motivating
fluid on one side Of the diaphragm which
seals the motivating fluid from the fluid
controlled by the valve.
VALVE, DIRECT-ACTING DIAPHRAGM: one which
closes with admiss ion of fluid pressure to
a diaphgragm and opens when pressure is
released .
15050
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BASIC MATERIALS AND METHODS
VALVE, DISCHARGE: on a compressor, the
valve which allows compressed refriger—
ant to flow from the cylinder to the dis—
charge main.
VALVE, EMERGENCY RELIEF: A manually oper-
ated valve for discharge of refrigerant
in case Of fire or other emergency .
VALVE, EXPANSION, AUTOMATIC: A device
which regulates refrigerant flow from
the liquid line into the evaporator to
maintain a constant evaporator pressure .
VALVE, EXPANSION, HAND: A manually operated
needle—type valve for controlling flow of
liquid refrigerant to an evaporator.
VALVE, EXPANSION, THEFNOSTATIC: A control-
ling device for regulating flow Of vol—
atile refrigerant into a cooling unit,
actuated by changes in evaporator pres—
sure and superheat of the refrigerant
leaving the cooling unit. The basic
response is to superheat .
VALVE, FLOAT. (I) Refrigerating valve
controlled by liquid level; (2) valve
actuated by float in a liquid container .
VALVE, RING.
(1) Stop valve between
receiver and liquid main; (2) stop valve
on boiler header .
VALVE, PACKLESS: valve which does not
use packing to prevent leaks around the
valve stem. Flexible material is gener—
ally used to seal against leaks and still
permit valve movement.
VALVE, PRESSURE REDUCING: A valve which
maintains a uni form pressure on its out—
let side irrespective of how the pressure
on its inlet side may vary above the
pressure to be maintained
VALVE, PRESSURE RELIEF: A valve held closely
by a spring or other means and designed
to automatically relieve pressure in
excess of its setting; also called a
safety valve
VALVE, PURGE: A device to allow fluid to
flow out of a system, particularly non—
condensable gases; also called a drain
valve .
VALVE, PRESSURE REDUCING: A valve which
maintains a uniform pressure on its outlet
side irrespective of how the pressure on
its inlet side may vary above the pressure
to be maintained.
VALVE, REVERSE-ACTING DIAPHRAGM: A valve
which opens with admission of fluid pres—
sure to a diaphragm and closes when pres—
sure is released.
VALVE, SERVICE; A valve intended to help
isolate an apparatus from the rest of the
system; may be a stop valve .

****** Result for Image/Page 13 ******
BASIC MATERIALS AND METHODS
SECTION 15050
VAPOR LOCK: The. formation of some vapor or all
VALVE SOLENOID: valve which is closed
vapor in a liquid line reducing weight flow
by gravity, pressure, or spring action
as compared to weight flow in liquid phase
and opened by the movement of a plunger
with the same pressure differential .
due to the magnetic action of an elec—
trically energi zed coil, or vice versa.
VAPOR LOCK DEVICE: An orifice, capillary tube,
or other device having a restricted passage
VALVE, STOP: A shutoff valve, other than
Of fixed size for liquid refrigerant.
a valve for controlling the flow.
restricts flow of vapor of that same liquid
to a lower rate of flow with the same pressure
In a compressor, the valve
VALVE, SUCTION;
difference.
which allows refrigerant to enter the
cylinder from the suction line and pre—
VENTILATION: The process of supplying or
vents return flow.
removing air by natural or mechanical means
Such air may or may
to or from any space.
VALVE, SUCTION PRESSURE REGULATING: An
not have been condi tioned.
automatic valve located between the evapor—
ator outlet and the compressor inlet that
VISCOSITY: That property of semi fluids, fluids ,
is responsive to its own outlet pressure
and gases by virtue of which they resist an
and functions to throttle the vapor flow
instantaneous change of shape or arrangement
so as to prevent the suction pressure at
It is the cause of fluid friction
of parts .
the compressor inlet from exceeding a
whenever adjacent layers of fluid move with
It is used primarily
selected value .
relation to each other .
to prevent overload on compressor motors .
VISCOSITY, ABSOLUTE: The force per unit area
VALVE, THERMAL: A valve controlled by a
required to produce unit relqtive velocity
thermally responsive element, e.g., a
between two parallel areas of fluid distance
thermostatic expansion valve which is
apart; also called coefficient of viscosity.
usually responsive to suction or evapor—
ator temperature.
VISCOSITY, KINEMATIC: The ratio of absolute
viscosity to density of a fluid.
VALVE, WATER REGULATOR: An automatic
valve to control the flow of cooling
VOLUME, SPECIFIC; The volume of a substance
water through a condenser .
per unit mass; the reciprocal of density .
VANE, RATIO: In air distributing devices,
WALL SECTION: A cross section of wall arranged
the ratio of depth of vane to shortest
chiefly to reveal conductivity character—
opening width between two adjacent grill
istics .
bars .
WATER, COOLING; Water used for condensation
VAPOR: A gas, particularly one near to
of refrigerant; condenser water.
equilibrium with the liquid phase of the
substance and which does not follow the
In a compressor, the water
WATER, JACKET:
it is usually used instead
gas laws .
used for cooling the cylinder head and/or
Of gas for a refrigerant and, in general,
walls .
for any gas below the critical temperature.
WATER, MAKE-UP: Water supplied to replenish,
VAPOR, SATURATED: vapor in equilibrium
as water replacing that lost by evaporation.
with its liquid: i.e.,
when the numbers
per unit time of molecules passing in two
WATER, RAW: (I) Any water used for ice making
directions through the surface dividing
except distilled water; (2) untreated water .
the two phases are equal.
WAX: A solid material which may separate on
VAPOR, SUPERHEATED: Vapor at a temperature
cooling of oil—refrigerant mixtures.
which is higher than the saturation tem—
perature (i.e., boiling point) at the
See drip.
WEEP :
existing pressure.
WHITE ROOM: A room that is free of any form
VAPOR, WATER: Used commonly in air con—
of measureable dust or bacteria.
ditioning parlance to refer to steam in
the atmosphere .
Restriction of area for a flow—
ing fluid, causing a loss in pressure by
The fraction by
VAPOR, WET, QUALITY OF:
(internal and external) friction without
weight of vapor in a mixture of liquid
loss of heat or performance of work;
and vapor .
throttling .
VAPOR BARRIER: A moisture impervious layer
WORK, EFFECTIVE ; The net mechanical energy
applied to the surfaces enclosing a humid
required by, or load imparted to, the pis—
space to prevent moisture travel to a
ton of a compressor .
point where it may condense due to lower
temperature .
WORK, INDICATED: Work equivalent of indicator
card area for a reciprocating compressor or
eng ine.
15050
- 29

****** Result for Image/Page 14 ******
SECTION 15062
ABSORPTION: This term applies to imrnersion
in a fluid for a definite period of time.
It is usually expressed as a percent of the
(CISPI)
weight of the dry pipe .
ANAEROBIC: Bacteria living without air .
(CISPI)
An anchor is usually pieces Of metal
used to fasten or secure pipes to the build—
(CISPI)
ing or structure.
AREA OF CIRCLE: To find the area of a cir-
cle, multiply the square of the radius by
pi. Area = Tr2.
(CISPI)
FILL: That portion of the trench exca—
vation which is replaced after the sewer
line been laid is called the backfill.
It is the material above the pipe up to
(CISPI)
the original earth line.
Backflow is the flow of water or
other liquids, mixtures or substances into
the distributing pipe of a potable supply
of water from any source other than that
(CISPI)
in tend ed.
BACKFLOW PREVENTER: This is a device or as-
sernbly designed to prevent backflow into
the potable water system. (CISPI)
BACK-SIPHONAGE: This is the term applied to
the flow of used water, wastes and/or con—
tamination into the potable water supply
piping, due to vacuums being established
in the distribution system, building ser—
(CISPI)
vice, water Nin or parts thereof.
BASE: Ioæst portion or lowest point of
a stack of vertical pipe. (CISPI)
BRANCH: A is any part of the piping
system other than a main riser i or stack.
(CISPI)
CAULKING: Caulking is the operation or
method of rendering a joint tight against
water or gas by means of plastic substances
such as lead and oakum. (CISPI)
CIRCUMFERENCE OF A CIRCLE: To find the peri-
meter or circumference of a circle, multi—
ply the diameter of the circle by pi.
(CISPI)
Circurnference •T D.
CLARIFIED SEWAGE: This is a terra used for
sewage from which suspended matter has been
(CISPI)
partly or completely removed.
CODE: The word code, as related to plumbing
work, usually means an ordinance with any
subsequent amendments thereto, or any
anergency rules and regulations which a
city or governing body may adopt to con—
trol the plumbing work within their juris—
diction. (CISPI)
COLIFORM GROUP OF BACTERIA: This is defined
as including all organisms considered in
the coli aerogenes group as set forth in
15062
CAST-IRON PIPE
the American Water Works Association and the
American Public Health Association IitZra—
(CISPI)
ture.
Stress which resists the ten—
COMPRESSION:
dency of two forces acting toward each
(CISPI)
other.
CONDUCTOR: A conductor is that part of the
vertical piping which carries the water
from the roof to the storm drain, which
starts either 6 inches above grade if out—
side the building, or at the roof sump or
(CISPI)
gutter if inside the building.
CROSS CONNECTION: A cross connection or inter-
connection is any physical connection between
a city water supply and any waste pipe, soil
pipe, sewer, drain, or any private or un—
certified water supply. Furthermore, it is
any potable water supply outlet which is
submerged or can be submerged in waste
and/or any other source of contamina—
(CISPI)
tion.
CRUDE OR RAW SEWAGE: This terminology applies
(CISPI)
to untreated sewage.
DEAD END: A dead end is a branch leading from
any soil, waste or vent pipe, building drain,
or building sewer, which is terminated at a
developed distance of two (2) feet or more
by means of a cap, plug or other fitting
not used for admi tting water or air to the
pipe, except branches serving as cleanout
(CISPI)
extensions .
DEVELOPED LENGTHS: The term developed length of
a pipe refers to the length measured along
the centerline of the pipe and fittings.
(CISPI)
DIAMETER: Unless specifically stated, the
term diameter is the nominal diameter as de—
(CISPI)
signed commercially.
DIGESTER AND DIGESTION; That portion of the
sewage treatment process where biochemical
decomposition OE organic matter takes place ,
resulting in the formation of simple organic
(CISPI)
and mineral substances.
DOMESTIC SEWAGE: Sewage originating princi—
pally from dwellings, business buildings,
institutions and usually thought of as not
However , in some
containing storm water .
localities it may include industrial wastes
and rain water from combination sewers.
(CISPI)
DRAIN: A drain is any pipe which carries
waste water or water—borne wastes in a
building drainage system. (CISPI )
DRAIN, BUILDING OR HOUSE: That part of the
lowest horizontal piping of a building
drainage system which receives and conveys
the discharge from soil, waste and drainage
pipes, other than storm drains, from within
the walls or footings of any building to the
(CISPI)
building sewer .

****** Result for Image/Page 15 ******
SECTION 15062
DRAINS, COMBINED: combined drain is that por-
tidn of the drainage system within a building
which carries storm water and sani tary
(CISPI)
DRAINS, STORM: Part of the IÜrizontaI piping
and its branches which convert sub—soil and/or
surface drainage from areas, courts, roofs or
(CISPI)
yards to the building or storm
DRAINS, SUBSOIL: Part of the drainage system
which conveys the subsoil ground or seepage
water from the footings of walls, or from un—
der buildings, to the building drain, storm
water drain or building sewer. (CISPI)
DRY WEATHER FLOW: This term refers to sewage
collected during the summer which contains
little or no ground water by infiltration
(CISPI)
and no storm t•ter at the time.
DUCTILITY: This is the property of elongation
above the elastic limit, but under the tensile
strength. (CISPI )
EFFLUENT: treated or partially treated,
flowing out of sewage treatment equ ipment.
(CISPI)
EASTIC LIMIT: The greatest stress which a ma—
teriai can withstand without a permanent de—
formation after release of the stress. (CISPI)
EROSION: The gradual destruction of metal or
other material by the abrasive action of liquids,
gases, solids or mixtures of these materials.
(CISPI)
EXISTING WORK: This applies to that portion of
a plumbing system which has been installed
prior to the current or contemplated addi—
(CISPI)
tion, alteration or correction.
FIXTURES, BATTERY OF: A battery of fixtures is
any group of tw or more similar adjacent fix—
tures which discharge into a cortunon horizon—
tal waste or soil branch. CISPI)
FIXTURES, COMBINATION: A combination fixture
is an integral unit such as a kitchen sink
and a laundry unit. CISPI)
FIXTURES, PLUMBING; Installed receptacles,
devices or appliances which are supplied with
water, or which receive liquids and/or dis—
charge liquids, or liquid—borne wastes, either
directly or indirectly into the drainage sys—
tern. (CISPI)
FIXTURE UNIT: A fixture unit is that• amount of
fixture discharge equivalent to seven and one—
half (7—1/2) gallons or rore; one (I) cubic
foot of wa per minute. (CISPI)
FLOOD LEVEL RIM: The top edge of the receptacle
(CISPI)
from which water overflows.
FLUSH VALVE: Device located at the bottom of
the tank for the purpose of flushing water
(CISPI)
closets and similar fixtures.
15062
CAST-IRON PIPE
FLUSHOMETER VALVE: A device which dis-
charges a predetermined quantity of wa—
ter to a fixture for flushing purposes
and is actuated by direct water pressure.
(CISPI)
The part of a foundation wall
FOOTING :
resting on the bearing soil, rock or
piling which transmits the super imposed
(CISPI)
load to the bearing material.
FRESH SEWAGE: This applies to sewage of
recent origin still containing free dis—
(CISPI)
solved oxygen.
ATERAL SEVER: A sewer which does not re-
ceive sewage from any other common sewer
(CISPI)
except house connections .
LEACHING WELL OR CESSPOOL: Any pit or re-
ceptacle having porous walls which permit
the contents to seep into the ground.
(CISPI)
LEADER: The piping from the roof which
(CISPI)
carries roof water.
MAIN SEWER: Also called the Trunk sewer;
the main stzti or principal artery of the
system oz sewage network to which branches
may be connected.
(CISPI)
MASTER PLUMBER; The master pluraber's 1i-
cense grants him the authority to install
and to assume responsibility for contrac—
tuai agreements pertaining to plumbing
The
and to secure any required permits.
journeyman plumber properly licensed is
allowed to install plumbing only under
the supervision of a master plumber.
(CISPI)
OFFSET : A combination of pipe, pipes and/or
fittings which join two approximately
parallel sections of the line of pipes.
(CISPI)
OUTFALL SEWERS : Those receiving sewage from
the collection system and carrying it to
the point of final discharge or treat—
ment. It is usually the largest sewer
of the entire system. (CISPI)
Sewage in which the or—
OXIDIZED SEVP.GE;
ganic matter has been co±ined with oxy—
gen and has become stable in nature.
(CISPI)
PIPE, HORIZONTAL: Any pipe or part thereof
which is installed in a horizontal posi—
tion or which makes an angle of less
(CISPI)
than 450 with the horizontal.
PIPE, INDIRECT vmSTE: A pipe that does not
connect directly with the drainage sys—
tem but conveys liquid wastes by dis—
charging into a plumbing fixture or re—
ceptacle which is directly connected
to the drainage system. (CISPI)

****** Result for Image/Page 16 ******
SECTION 15062
PIPE, LOCAL VENTILATING: A pipe on the fix-
ture side of the trap through vhich pipe
vapors or foul air can be removed from a
room or fixture. (CISPI)
PIPE, SOIL: Any pipe which conveys to the
building drain or building seær the dis—
charge of one or more water closets and/or
the discharge Of any other fixture re—
ceiving fecal matter, with or without the
(CISPI)
discharge from other fixtures.
PIPE, SPECIAL WASTE: A drain which receives
one or more wastes which require treatment
before entry into the normal plumbing sys—
tan; the special waste pipe terminates at
the treatment device on the premises.
(CISPI)
PIPE, VERTICAL; Any pipe or part thereof
which is installed in a vertical position
or which makes an angle of not more than
(CISPI)
450 with the vertical.
PIPE, A pipe which conveys only I i —
quid or liquid-borne waste, free of fecal
matter. (CISPI)
PIPE, RISER: A supply pipe
which extends vertically one full story
or more to convey water to branches or
(CISPI )
f ixtures.
PIPES, ATER DISTRIBUTION: convey water
from the service pipe to its points of
usage on the premise s. (CISPI)
PIPES, SERVICE: That portion of the
water piping which supplies one or more
structures or premises and which extends
from the public or private main in the
street, alley or easement to the meter or ,
if no meter is to be provided, to the first
stop cock or valve inside the premises.
(CISPI)
PITCH: used to indicate the amount of slope
or grade given to horizontal piping and
expressed in inches of vertically projected
drop per foot on a horizontally projected
(CISPI)
run Of pipe.
PLUMBING: Includes the practice, materials
and fixtures used in the installation, main—
tenance, extension and alteration of all pip—
ingr fixtures, appliances and appurtenances
in connection with any of the following :
Sanitary drainage or storm drainage facili—
ties; the venting system and the public or
private water—supply systems, within or ad—
jacent to any building, structure or convey—
ance; also the practice and materials used
in the installation, maintenance, extension
or alteration of water—supply systems and/or
the storm water, liquid waste or sewage
system Of any premises to their connection
with any point of public disposal or other
acceptable termina. (C ISPI )
CAST-IRON PIPE
PLUMBING INSPECTOR: Any person who, under
the supervision of the authority havin•g
jurisdiction, is authorized to inspect
plumbing and drainage as defined in the
code for the municipality, and complying
with the laws of licensing and/or regis—
tration of the State, City or county.
(CISPI)
PRECIPITATION: The total measurable supply
of water received directly from the clouds
It is
as snow, rain, hail and sleet.
usually expressed in inches per day, month
(CISPI)
or year.
PRIVATE USE: Applies to a toilet room or
intended specifically for the use
of an individual or family and such visi—
tors as they may permit to use such
toilet or (CISPI)
PUBLIC USE: Applies to toilet rooms and bath—
rooms used by employees, occupants, visitors
or patrons, in or about any premises. This
term also applies to locked toilet rooms
or bathrooms to which several occupants
or employees on the premises possess keys
(CISPI)
and have access.
PUTREFACTION : Biological decomposition of
organic matter with the production of ill—
smelling products is known as putrefaction.
It usually takes place when there is a de—
(CISPI)
ficiency of oxygen.
REVENT (Individual vent) : That part of a vent
pipe line which connects directly with any
individual waste or group of wastes, under—
neath or back of the fixture, and extends
either to the main or branch vent pipe.
(CISPI)
ROUGHING IN: A term concerning the installa—
tion of all parts of the plumbing system
which can be completed prior to the installa—
tion Of the fixtures. This includes
drainage, water supply, vent piping and the
(CISPI)
necessary fixture backing.
SANITARY SEVER: The conduit or pipe carrying
It may include storm water ,
sanitary sewage.
and also the infiltration of ground water.
(CISPI)
Sanitary sewage undergoing
SEPTIC SEWAGE:
(CISPI)
putrefaction .
SEPTIC TANK: A receptacle which receives the
discharge of a drainage system or part there—
of, and is designed and so constructed to sep—
arate the solids from the liquid, . digest the
organic matter through a period of deten—
tion, and allow the liquids to discharge into
the soil outside the tank through a system
of open—joint or perforated piping, or into
(CISPI)
a disposal pit.

****** Result for Image/Page 17 ******
SECTION 15062
SEWAGE; Any liquid waste containing animal,
table or chemical wastes in suspension or
(CISPI)
tion.
SEWER, BUILDING: Also called house sewer.
vege—
solu—
It is
that part Of the horizontal piping of a drainage
system extending from the building drain, storm
drain and/or subsoil drain to its connection in—
to the public sewer, private seær, sewage
treatment tank or other point of disposal, and
carrying the drainage of but one building or
(CISPI)
part thereof.
SEWER, BUILDING STORM: The extension from the
building storm drain. to the public storm sewer ,
combined setver, or other point of disposal .
(CISPI)
SEWER, PRIVATE: A sewer located on private prop—
erty owned and maintained which conveys the
drainage of one or more buildings to a public
sewer or to a privately owned sewage disposal
system. (CISPI)
SEWER, STORM: A seær used to convey
surface VRter, condensate, cooling water or
similar water wastes, exclusive of sexage
(CISPI)
and industrial wastes.
SLICK: Thin oily film usually present which
gives the characteristic appearance to the
surface of water into which sewage or oily waste
(CISPI)
is discharged.
SLUDGE : The accumulated suspended solids of
sewage deposited in tanks, beds or basins, mixed
with more or less water to form a semiliquid
(CISPI)
mass called sludge.
STACK: The vertical main of a system of soil,
(CISPI)
waste or vent piping.
STACK VENT: The extension of a soil or waste
stack above the highest horizontal drain con—
(CISPI)
nected to the stack.
STALE SEV•mGE; Contains little or no oxygen and
is, as yet, free from putrefaction.
(CISPI)
STRAIN: Change of shape or size of a body pro—
(CISPI)
duced by the action of stress.
STRESS: maen external forces act on a body,
they are resisted by reactions within the body
(CISPI)
which are called stresses.
SUBBIAIN SEWER (Also called Branch Sewer) : A
sewer into which the sewage from or more
lateral sewers is discharged. (CISPI)
SUBSOIL DRAIN: Drain which receives only subsur—
face or seepage water and conveys it to a
(CISPI)
place of disposal.
SUMP: A tank or pit which receives the discharge
from drains or other wastes, located below the
normal grade of the gravity system, and which
must be emptied by mechanical means. (CISPI)
TENSION: That stress which resists the tendency
of forces acting from each other to
15062
CAST-IRON PIPE
pull apart two adjoining planes of a
body. (CISPI)
TRAP: A fitting or device so designed and
constructed as to provide, when properly
vented, a liquid seal which will prevent
the back passage of air without materi—
ally affecting the flow of sewage or
(CISPI)
Rste water through it.
TRAP SEAL: The vertical distance between
the crown weir and the top of the dip
(CISPI)
of the trap.
TURBULENCE: Any deviation from parallel
flow in a pipe due to rough inner wall
surfaces, obstructions or directional
(CISPI)
changes.
UNDERGROUND PIPING: Piping in contact with
Pipe in a tunnel
the earth below grade.
or in a watertight trench is not included
within the scope of this term. (CISPI)
USED: Plumbing materials, fixtures or
equipment which have been removed from
(CISPI )
a previous installation.
VACUUM: Any pressure less than that exert—
ed by the atmosphere and may be termed
a negative pressure. (CISPI)
VELOCITY: Time rate of motion in a given
(CISPI)
direction and sense.
VENT, CIRCUIT: A branch vent that serves
two or more traps and extends from in
front of the last fixture connection of
a horizontal branch to the vent stack.
(CISPI)
VENT, CONffON: Also called dual vent, is a
vent connecting at the junction of two
fixture drains and serving as a vent for
both fixtures.
(CISPI)
VENT, CONTINUOUS: A vent that is a contin-
uation of and in a straight line with
the drain to which it connects. A contin—
uous vent is further designed by the
angle which the drain and vent make with
the horizontal at the point of connec—
tion; for example, vertical continuous
450 continuous waste—
and—vent; and flat (small angle) contin—
(CISPI )
uous waste—and—vent.
VENT, LOOP: A vent from a single fixture
or battery of fixtures which is connected
into the same stack into Which the fix—
tures discharge. If the loop vent serves
mre than one fixture, it is one type of
circuit vent.
(CISPI)
VENT STACK: A vertical vent pipe installed
primarily for the purpose of providing
circulation of air to and from any part
of the drainage system. A vent stack
or main vent is that part of a venting
system to which circuit vents are connect—
ed. Branch vents, revents or individual

****** Result for Image/Page 18 ******
CAST-IRON PIPE
SECTION 15062
vents may be led to and connected with a
The foot Of the vent stack
vent stack.
may be connected either into a horizontal
drainage branch or into a soil or waste
(CISPI)
stack.
VENT SYSTEM: A pipe or pipes installed to
provide a flow of air to or from a drain—
age system or to provide a circulation of
air within such system to protect trap
seals from siphonage adn back pressure .
(CISPI)
VENT, VET: A vent which receives the dis—
charge of wastes other than from water
(Cispr)
closets.
VENT, YOKE: A pipe connecting upward from
a soil or waste stack to a vent stack for
the purpose of preventing pressure changes
(CISPI)
in the stacks.
VENTING, STACK: A method of venting a fix—
ture through the soil and waste stack.
(CISPI)
VENTS, INDIVIDUAL: separate vents for each
(CISPI)
fixture.
The discharge from any fixture, ap—
WASTE:
pliance or appurtenance in connection with
the plumbing system, which does not contain
fecal matter. For example, the liquid
from a lavatory, a tub, a sink or drinking
(CISPI)
fountain is referred to as waste.
15062
-5

****** Result for Image/Page 19 ******
SECTION 15400
. ACCESSIBLE: Having access thereto but which
first raay require the renoval Of an access
panel, door or similar obstruction. "Read—
ily accessible" means direct access with—
out the necessity of removing or moving
any panel, door or similar obstruction.
(NSPC)
AIR BREAK (DRAINAGE SYSTEM): A piping ar-
rangement in which a drain from a fixture ,
appliance or device discharges indirectly
into a fixture, receptacle or interceptor
at a point below the flood level rim of
the receptacle so installed as to prevent
( NSPC)
backflov or siphonage.
The unobstructed
AIR GAP (DRAIN AGE SYSTEM) :
vertical distance through free atmos—
phere between the outlet of waste pipe
and the flood level rim of the receptacle
into which it is discharging. (NSPC)
The un—
AIR GAP (WATER DISTRIBUTION SYSTEM) :
obstructed vertical distance through the
free atmosphere between the lowest opening
from any pipe or faucet supplying water
to a tank, plumbing fixture or other de—
vice and the flood level rim of the re—
(NSPC)
ceptacl e.
AREA DRAIN: A receptacle designed to collect
surface or storm water from an open area.
(NSPC)
ASPIRATOR; A fitting or device supplied with
water or other fluid under positive pres—
sure which passes through an integral ori—
f ice or "constriction" causing a vacuum.
(NSPC)
AUTOPSY TABLE: A fixture or table used for
the postmorten examination of a body. (NSPC)
BACKFLOW: The flow of water or other liquids
or mixtures or substances into the distri—
buting pipes of a potable supply of water
from any source or sources other than its
intended source. Back—siphonage is one
type of backflow. (NS?C)
BACKFLOW CONNECTION: Any arrangement whereby
(NSPC)
backflow can occur.
BACKFLOW PREVENTER: A device or means to
prevent backflow. (NSPC )
BACKFLOW PREVENTER, REDUCED PRESSURE ZONE
TYPE: An assembly of differential valves
and check valves including an automati—
cally opened spillage port to the atrnos—
(NSPC)
pher e.
BACK-SIPHONAGE: The flowing back of used,
contaminated or polluted from a
plumbing fixture or vessel or other
sources into a potable water supply pipe
duct due to a negative pressure in such
ßSPC)
pipe.
BACK VALVE; A device installed in a
drain pipe to prevent backflow. (NS?C)
15400
PLUMBING
BAROMETRIC LOOP: A loop of pipe rising .ap-
proxirrn tely 35 feet, at its topnnst point,
above the highest fixture it supplies.
(NSPC)
BATTERY OF FIXTURES: Any group of two or
more similar adjacent fixtures which dis—
charge into a cormon horizontal waste or
(NSPC)
soil branch.
BEDPAN STEAMER: A fixture used for scalding
bedpans or urinals by direct application
of steam. (NSPC)
BEDPAN WASHER: A fixture designed to wash
bedpans and to flush the contents into the
soil drainage system. It may also provide
for steaming the utensils with steam or hot
(NS?C)
water.
BEDPAN vmSHER HOSE: A device supplied with
hot and cold water and located adjacent to
a water closet or clinic sink to be used
(NSPC)
for cleansing bedpans .
BOILER BLOW-OFF: An outlet on a boiler to
permit emptying or discharge of sediment.
(NSPC)
BOILER BLOW-OFF TANK: A vessel designed to
receive the discharge from a boiler blow—
off outlet and to cool the discharge to a
temperature which permits its safe dis—
charge to the drainage system. (NSPC)
BRANCH: Any part of the piping system other
(NSPC)
than a riser, main or stack.
BRANCH, FIXTURE: see "Fixture Branch"
(NSPC)
BRANCH, HORIZONTAL: see "Horizontal Branch"
(NSPC)
BRANCH INTERVAL: A distance along a soil or
waste stack corresponding in general to a
story height, but in no case less than 8
feet, within which the horizontal branches
from one floor or story of a building are
(NSPC)
connected to the stack.
BRANCH VENT A vent connecting one or more
ind ividual vents with a vent stack or
stack vent. (NSPC)
BUILDING DRAIN: That part of the lowest pip-
ing of a drainage system which receives the
discharge from soil, waste and other drain—
age pipes inside the walls of the building
and conveys it to the building sewer beg in—
ning •3 feet outside the building wall. (NSPC)
BUILDING DRAIN - COMBINED: A building drain
which conveys both sewage and storm water
(NSPC)
or other drainage.
— SANITARY : A building drain
BUILDING DRAIN
sewage only.
(NSPC)
which conveys
- STORM: A building drain
BUILD ING DRAIN
storm water or other drainae
which conveys
(NSPC)
but no sewage.

****** Result for Image/Page 20 ******
SECTION 15400
BUILPING SEWER: That part of the drainage system
which extends from the end of the building drain
and conveys its discharge to a public sewer ,
pr ivate sewer, individual sewage—disposal sys—
(NSPC)
tem, or other point of disposal.
BUILDING SEWER - COMBINED: A building sewer
which conveys both sewage and storm or
(NSPC)
other drainage.
BUILDING SEWER - SANITARY; A building sewer
(NSPC)
which conveys sewage only.
BUILDING SEWER - STORM: A building sewer which
conveys storm water or other drainage but o
(NSPC )
sewage.
BUILDING SUBDUIN: That portion of a drainage
system which does not drain by gravity into the
(NSPC)
building sewer.
BUILDING TRAP: A device, fitting or assembly of
fittings installed in the building drain to
prevent circulation of air between drain—
age system of the building and the building
(NSPC)
sewer.
CESSPOOL: A lined and covered excavation in the
ground which receives the discharge Of domes—
tic sewage or other organic wastes from a
drainage system, so designed as to retain the
organic natter and solids, but permitting the
liquids to seep through bottom sides.
(NSPC)
CIRCUIT VENT: A branch vent that serves two or
more •traps and extends from the downstream
side of the highest fixture connection of a
horizontal branch to the vent stack. (NSPC)
CLEAR WATER WASTE: cooling water and conden-
sate drainage from refrigeration, and air
conditioning equipment; cooled condensate
from steam heating systems; cooled boiler
blow—down water; waste water drainage from
equipment rooms and other areas where water
is used without an appreciable addition of
oil, gasoline, solvent, acid, etc., and
treated effluent in which impurities have
been reduced below a minimum concentration
consid ered harmful.
(NSPC)
CLINIC SINK (BEDPAN HOPPER): A sink designed
primar ily to receive wastes from bedpans pro—
vided with a flush rim, integral trap with a
visible trap seal, having the same flu shing
and cleansing characteristics as a kter
closet.
(NSPC)
COMBINATION FIXTURE: A fixture combining one
sink and laundry tray or a tm or three—
canpartment sink or laundry tray in one unit.
(NSPC)
COMBINED BUILDING DMIN: see "Building Drain -
(NSPC)
combined .
COMBINED BUILDING SEWER: see "Building sewer -
(NSPC)
Combined "
COMBINATION AND VENT SYSTEM: A specially
designed system of ste piping embodying the
15400 - 2
PLUMBING
horizontal wet venting Of one or more
sinks or floor drains by means of a
common waste and vent pipe adequately
sized to provide free movement of air
above the flow line of the drain. (NSPC)
COMMON VENT: A vent connected at a com—
mon connection of two fixture drains
and serving as a vent for both fixtures.
(NSPC)
CONDUCTOR: The wa ter conductor from the
roof to the building storm drain, com—
bined building sewer, or other means of
disposal and located inside of the
bu ilding .
(NSPC )
CONTINUOUS VENT: A vertical vent that is
a continuation of the drain to which it
(NSPC)
connects.
CONTINUOUS V'ÄSTE: A drain from two or
more fixtures connected to a single
trap. (NSPC)
CRITICAL LEVEL: The critical level mark-
ing on a backflow prevention device or
vacuum breaker is a point established
by the manufacturer and usually stamped
on the device by the manufacturer which
determines the minimum elevation above
the flood level rim of the fixture or
receptacle served at which the device
may be installed. When a backflow pre—
vention device does not bear a critical
level marking, the bottom of the vacuum
breaker, combination valve, or the bottom
of any approved device shall constitute
critical level.
(NSPC)
CROSS CONNECTION: Any connection or ar-
rangement between two otherwise separate
piping systems, one of which contains
potable water and the other either water
of unknown or questionable safety or
steam, gas, or chemical whereby there
may be a flow from one system to the
other, the direction of flow depending
on the pressure differential between
(See Backflow and
the systems.
Back—Siphonage) .
(NSPC)
DEAD END: A branch leading from a soil,
waste or vent pipe, building dra in, or
building sewer, and terminating at a
developed length of 2 feet or more by
means of a plug, cap or other closed
fi tting.
(NSPC)
DEVELOPED LENGTH: The length of a pipe
line measured along the centerline of
the pipe fittings.
(NSPC)
DIAMETER: The diameter as desig—
nated coraraercia Ily. (NSPC )
DOUBLE OFFSET: changes of direction
insta I led in succession or series in a
continuous pipe.
(NSPC)

****** Result for Image/Page 21 ******
SECTION 15400
DOWNSPOUT: The rainleader from the roof to
the building storm dra in, combined build—
ing sever, or other means of disposal
and located outside the building. (NSPC)
DOPESTIC SEWAGE: The water-Enrne æstes
derived from ordinary living processes.
(NSPC)
DRAIN: Any pipe carries water
or water—borne wastes in a building drain—
age system. (NSPC)
DRAINAGE PIPE: see inage System"
(NSPC)
DRAINAGE SYSTEM: Includes all the piping,
wi thin public or private premises, which
conveys sewage, rain water or other liquid
It does not
wastes to a point of disposal.
include the Nins of a public sewer sys-
or private or public sewage—treatment
or disposal plant. (NSPC)
DRAINAGE SYSTEM, BUILDING GRAVITY: A drain-
age system which drains by gravity into
the building sewer. (NSPC)
DRAINAGE SYSTEi.i, SUB-DÜILD1äG:
ing Subärain " . (NS?C)
DRY WELL: see "Leaching Well".
DUAL VENT: see "Cormon Va-itn.
See "Build—
(NSPC)
(NSPC)
DWELLING UNIT - MULTIPLE: A room or group
of rooms forming a single habitable unit
with facilities which are used or intended
to be used for living, sleeping, cooking
and eating; and whose sewer connections
and water supply within its own premise
are shared with one or more otlpr dwelling
(NSPC)
units.
DWELLING UNIT - SNGLE: A room or group of
rooms forming a single habitable unit with
facilities which are used or intended to
be used for living, sleeping, cooking and
eating; and whose sewer connections and
water supply are within its own prznise
separate from and completely independent
of any other dwelling. (NSPC)
FIXTVÜ: see "Plumbing Fixture" . (NSPC)
FIXTURE BRANCH: A pipe connecting several
f ixtures . (NSPC)
FIXTURE DRAIN: The drain from the trap of
a fixture to the junction of that drain
with any other drain pipe.
(NSPC)
FIXTURE SUPPLY: The water supply pipe con-
necting a fixture to a branch sup—
ply pipe or directly to a main R ter sup—
ply pipe. (NSPC)
FIXTURE UNIT (DRAINAGE - d.f.u.) : A measure
of the probable discrnrge into the drain—
age system by various types of plumbing
fixtures. The drainage fixture—unit value
for a particular fixture depends on its
volume rate of drainage discharge, on the
15400
PLUMBING
time duration of a single supply oper4tion ,
and on the average ti.me between successive
(NSPC)
operations.
FIXTURE UNIT (SUPPLY - s.f.u.): A measure of
the probable hydraulic derand on the water
supply by var ious types of plumbing fixtures
The supply fixture—unit value for a particu—
lar fixture depends on its volume rate of
supply, on the time duration of a single
supply operation, and on the average time
between successive operations. (NSPC)
FLO@ LEVU: see "Flood Level Rim". (NSPC)
FLOOD LEVEL RIM: The edge of the receptacle
form which water overflows. (NSPC)
FLOODED; The condition which results when
the liguid in a container or receptacle
rises to the flood—level rim. (NSPC)
FLOW PRESSURE: The pressure in the water sup-
ply pipe near the faucet or water outlet
while the faucet or water outlet is wide—
(NSPC)
open and flowing.
FLUSHING TYPE FLOOR DRAIN: A floor drain
which is equipped with an integral water sup—
ply, enabling flushing of the drain recep—
(NSPC)
tor and trap .
FLUSH VALVE: A device located at the bottom
of a tank for flushing water closets and
similar fixtures:
(NSPC)
FLUSHOMETER VALVE: A device which discharges
a predetermined quantity of water to fix—
tures for flushing purposes and is closed
by direct water pressure. (NSPC)
FROSTPROOF CLOSET: A hopper with no water
in the bowl and With the trap and water sup—
ply control valve located below frost
(NSPC)
line.
GRADE; The fall (slope) of a line of pipe
in reference to a horizontal plane .
In
drainage it is usually expressed as the
fall in a fraction of an inch per foot
(NS?C)
length of pipe.
GREASE INTERCEPTOR: see "Interceptor" .
(NSPC)
(NSPC)
GREASE TPAP: see "Interceptor"
WÄTF.R: Subsurface water occupying the
zone Of saturation.
A. Confined Ground body Of ground
water overlain by material sufficiently
impervious to sever free hydraulic connec—
tion with overlying ground water .
B. Free Ground water in the
zone of saturation extending down to the
(NSPC)
first impervious barrier.
see " supports"
(NSPC)
HANGERS :

****** Result for Image/Page 22 ******
SECTION 15400
HORIZONTAL BRANCH DRAIN: A drain branch pipe ex-
tending laterally from a soil or waste stack
or building drain, with oz without vertical
sections or branches, which receives the dis—
charge from one or more fixture drains and
conducts it to the soil or waste stack or to
the building drain. (NSPC)
HORIZONTAL PIPE: Any pipe or fitting which
makes an angle of less than 450 with the hori—
(NSPC)
zontal .
HOUSE DRAIN:
HOUSE SEWER:
HOUSE TRAP:
see "Building Drain"
See "Building Sewer" .
(NSPC)
(NSPC)
See "Building Trap n
(NSPC)
INDIVIDUAL SEWAGE DISPOSAL SYSTEM: A system
for disposal of domestic sewage by mæns of a
septic tank, cesspool or mechanical treatment,
designed for use apart from a public sewer to
serve a single establishment or building .
(NSPC)
INDIRECT ASTE PIPE: A waste pipe which does
not connect directly with the drainage sys—
te, but which discharges into drainage
system through an air break or air gap into
a trap, fixture, receptor or interceptor.
(NSPC )
INDIVIDUAL VENT: A pipe ü•ustalled to vent a
fixture drain. It connects with the vent
system above the fixture served or terminates
outside the building into the open air (NSPC)
INDIVIDUAL WATER SUPPLY: A supply other than an
approved public water supply which serves one
(NSPC)
or more families.
INDUSTRIAL VASTES: Liquid or liquid-borne
wastes resulting from the processes employed
in industrial and connercial establishments.
(NSPC )
INSANITARY: Contrary to sanitary principles——
injur lous to health. (NSPC)
INTERCEPTOR: A device designed and installed so
as to separate and retain deleterious, hazard—
ous, or undesirable matter from normal k stes
while permitting normal sesage or liquid
wastes to discharge into the drainage systern
(NSPC)
by gravity.
INSTALLED: Altered, changed or a new installation.
(NSPC)
LEACHING WELL or PIT: A pit or receptacle having
porous which permit the contents to seep
into the ground.. (NSPC)
LEADER: An exterior vertical drainage pipe for
conveying storm water fran roof or gutter
drains. (NSPC)
LIQUID WASTE: The discharge from any fixture,
appliance, area or appurtenance, which does not
(NSPC)
contain human or animal waste matter.
15400
PLUMBING
LOAD FACTOR: The percentage of the total
connected fixture unit flow which is
likely to occur at any point in the
drainage system. (NSPC)
LOCAL VENTILATING PIPE: A pipe on the
fixture side of the trap through which
vapor or foul air is removed from a
(NSPC)
fixture .
LOOP VENT: A circuit vent which loops
back to connect with a stack vent in—
(NSPC)
stead of a vent stack.
PIAIN: The principal pipe artery to
which branches may be connected. (NSPC)
(NSPC)
MAIN SEWER: see "Public Sewer".
VENT: The pr incipal artery of the
ven ting system to which vent branches
may be connected. (NSPC )
MULTIPLE DWELLING: Building containing
or more dwelling units.
(NSPC)
NONPOQABLE nTER: Water not safe for
drinking or for personal or culinary
(NSPC)
use.
OFFSET: A combination of elbows or bends
which brings one section Of the pipe out
of line but into a line parallel with
the other section. (NSPC)
OIL INTERCEPTOR: see "Interceptor". (NSPC)
See "Grade"
PITCH:
(NSPC)
PLUMBING SYSTEM: Includes the water supply
and distribution pipes, plumbing fix—
tures and traps; soil, waste and vent
pipes, sanitary and storm drains and
building sewers including their res—
pective connections, devices and appur—
tenances to an approved point of dis—
(NSPC)
posaI .
(NSPC)
POOL: See " Swimning Pool" .
POTABLE -ATER: water free from impuri-
ties present in amounts sufficient to
cause disease or harmful physiological
effects and conforming in its bacteri—
ological and chemical quality to the
reuqirements of the Public Health Ser—
vice Drinking Water Standards or the
regulations of the public health auth—
ority having jurisdiction.
(NSPC)
PRIVATE SEWER: A sewer not directly con-
trolled by public authority . (NSPC)
PUBLIC SEWER: A conmon sewer directly
controlled by public author ity. (NSPC)
PUBLIC WATER MAIN: A water supply pipe
for public use controlled by public
author i ty .
(NSPC)

****** Result for Image/Page 23 ******
SECTION 15400
RECEPTOR: A fixture or device which re—
ceives the discharge from indirect waste
(NSPC)
pipe s.
ÜLIEF VENT: An auxiliary vent which per—
mits additional circulation of air in or
between drainage and vent systems. (NSPC)
RETURN OFFSET: A double offset installed
so as to return the pipe to its original
(NSPC)
al ig nment.
EVENT PIPE: see "Individual vent". (NSPC)
RIM: An unobstructed open edge of a fix—
ture. (NSPC)
RISER: A water supply pipe which extends
vertically one full story or more to con—
vey water to branches or to a group of
(NSPC)
fixtures.
ROOF DRAIN : A drain in stalled to receive
water collecting on the surface of a
roof and to discharge it into a leader
(NSPC)
or a conductor.
ROUGHING-IN: The installation of all parts
of the plumbing system which can be com—
pleted prior to the installation of fix—
This includes drainage, sup—
Cures
ply, and vent piping, and the necessary
f ixture supports, or any fixtures that
are built into the structure. (NSPC)
SAND FILTER; A treatment device or struc—
tuze, constructed above or below the sur—
face of the ground, for removing solid or
colloidal material of a type that cannot
be removed by sedimentation, from septic
(NSPC)
tank effluent.
SAND INTERCEPTOR: see "Interceptor"
(NSPC)
(NSPC)
SAND TRAP: See Interceptor".
SANITARY SEWER: A sewer which carries sew—
age and excludes storm, surface and
(NSPC)
ground water.
see "Leaching Well" .
SEEPAGE WELL or PIT:
(NSPC)
SEPARATOR: see .
(NSPC )
SEPTIC TANK : A watertight receptacle which
receives the discharge of a building sani—
tary drainage system or part thereof, and
is designed and constructed so as to sep—
arate solids from the liquid, digest or—
ganic natter through a period of detention,
and allow the liquids to discharge into
the soil outside the tank through a systan
of open joint or perforated piping, or a
(NSPC)
seepage pit.
SEWAGE: Any liguid wa ste containing an imaI
or vegetable in suspension or solu—
tion, and may include liquids containing
(NSPC)
chemicals in solution.
15400
PLUMBING
SEWAGE EJECTORS: A device for lifting *wage
by entra ining it in a high velocity jet of
(NSPC)
steam, air or water .
SES•AGE PUMP : A permanently installed mechani—
cal device other than an ejector for remov—
ing sewage or liquid waste from a sump.
(NSPC )
SIDE VENT : A vent connecting to the drain
pipe through a fitting at an angle not
greater than 450 to the vertical. (NSPC)
see "Diameter". (NSPC)
SIZE OF PIPE AND TUBING:
(NSPC)
See "Grad e 't .
SLOPE :
SOIL PIPE: A pipe which conveys sewage con—
taining human or animal waste to the build—
(NSPC)
ing drain or building sewer .
(NSPC)
See "Stack vent" .
SOIL VENT:
SPECIAL WASTES: wastes which require special
treatment before entry into the normal
plumbing system. (NSPC)
SPECIAL vmSTE PIPE: Pipes which convey special
(NSPC)
wastes.
STACK: A general term for any vertical line
of soil, waste, vent or inside conductor
piping. This does not i.nclude vertical
fixture and vent branches that do not extend
through tYE roof or that pass through not
more than two stories before being reconnect—
ed to the vent stack or stack vent. (NSPC )
STACK GROUP: A group of f ixtures located ad—
j acent to the stack so that by means of
proper fittings, vents may be reduced to a
minimum. (NSPC)
STACK VENT: The extension of a soil or waste
stack above the highest horizontal drain
(NSPC)
connected to the stack.
STACK VENTING : A method Of venting a fixture
or fixtures through the soil or waste
(NSPC)
sta ck.
STERILIZER, B01LING TYPE: A fixture (non-
pressure type) used for boiling instruments,
utensils, and/or other equipment (used for
disinfection) and may be portable or con—
nected to the plumbing system) (NSPC)
STERILIZER INSTRU}ENT: see sterilizer,
(NSPC)
Boiling Type " .
STERILIZER, PRESSURE, INSTRUMENT WASHER:
A fixture (pressure vessel) designed to
both and sterilize instruments during
the operating cycle of the fixture. (NSPC )
STERILIZER, PRESSURE (AUTOCLAVE) : A fixture
(pressure vessel) designed to use steam
under pressure for sterilizing .
See
"Sterilizer, Boiling Type "
(NSPC)

****** Result for Image/Page 24 ******
SECTION 15400
STER.ILIZER VENT: A separate pipe or stack, in-
directly connected to the building drainage
system at t.he lower terminal, which receives
the vapors frora nonpressure sterilizers, or
the exhaust vapors from pressure sterili zers,
and conducts the vapors directly to the outer
Sometimes called vapor, steam, atmos—
(NSPC)
phere or exhaust vent.
STERILIZER, WATER: Device for sterilizing
(NSPC)
and stor ing sterile water.
STILL: Device used in distilling liquids. (NSPC)
STORM DRAIN: see "Building Storm Drain .
STORM SEWER: A sewer used for conveying ra in
wa ter, surface water, condensate, cooling water ,
(NSPC)
or similar liquid wastes.
SUBSOIL DR.AIN: Drain which collects subsurface
or seepage water and conveys it to a place
of disposal. (NSPC)
SUMP: A tank or pit which receives sesæge or
liquid waste, located below the normal grade
of the gravity system and which must be emptied
(NSPC)
by mechanical means.
SUMP PUMP : A permanently in stalled mechanical
device other than an ejector for removing sew—
age or liquid waste from a sump. (NSPC)
Devices for supporting and secur ing
SUPPORTS :
pipe, fixtures and equipment. (NSPC)
SWIMMING POOL: Any structure, basin, chamber
or tank containing an artificial body of water
for swirming, diving or recreational bathing
and having a depth of feet or more at any
(NSPC)
point.
TRAP: A fitting or device which provides a
liquid seal to prevent the emission of sewer
gases without materially affecting the flow
of sewage or waste water through it.
(NSPC)
TRAP AN•I: That portion of a fixture drain be—
(NSPC)
tween a trap and its vent.
TI•uP PRIER: A device or system of piping to
reintain a seal in a trap.
(NSPC)
TNP SEAL: The vertical distance between the
crown æir and the top of the dip of the
(NSPC)
trap.
VACUUM: Any pressure less than tha exerted
(NSPC)
by the atmosphere.
VACUUM BREAKER: See "Backflow Preventer". (NSPC)
VACUUM BREAKER, NONPRESSURE TYPE (ATMOSPHERIC) :
A vacuum breaker which is not designed to be
(NSPC)
subj ect to static line pressure.
VACUUM BREAKER, PRESSURE TYPE: A vacuum breaker
designed to operate under conditions of static
line pressure. (NSPC)
15400
VACUUM RELIEF VALVE: A
excessive vacuum in a
(NSPC)
VENT PIPE: Part of the
VENT STACK: A vertical
PLUMBING
device to prevent
pressure vessel .
vent system. (NSPC)
vent pipe install—
ed to provide circulation of air to and
from the drainage system and which ex—
tends through one or more stories.
(NSPC)
VENT SYSTEM: A pipe or pipes ins tailed
to provide a flow of air to or from a
drainage system or to provide a circu—
lation of air within such system to
protect trap seals from siphonage and
(NSPC)
back pressure.
VERTICAL PIPE: Any pipe or fitting which
Nkes an angle of 450 or less with the
(NS?C)
vertical .
HUNG WATER CLOSET: A water closet
installed in such a way that no part
of the water closet touches the floor.
(NSPC)
WATER DISTRIBUTING PIPE: A pipe within
the build ing or on the premises whj.ch
conveys water from the water—service
(NSPC)
pipe to the point Of usage.
(NSPC)
See "Sewage Ejector"
LIFTS:
WATER IAIN : A water supply pipe for public
(NSPC)
use.
vmTER OUTLET : A discharge opening th.rough
which water is supplied to a fixture,
into the atmosphere (except into an open
tank which is part of the water supply
systera) , to a boiler or heating system,
to any devices or equipment requiring
water to operate but which are not part
of the plumbing system. (NSPC)
WATER RISER PIPE: see "Riser"
(NS?C)
SERVICE PIPE: The pipe from the
water main or other source of potable
water supply to the water distributing
system of the building served. (NSPC)
WATER SUPPLY SYSTEM; The water service
pipe, the water—distributing pipes, and
the necessary connecting pipes, fittings
and control valves and all appurtenances
in or adj acent to the building or
(NSPC)
pr emises.
WET VENT: A vent which receives the d is—
charge of wastes other elan from water
(NSPC)
closets and kitchen sinks.
YOKE VENT : A pipe connecting upward from
a soil or waste stack to a vent stack
for the purpose of preventing pressure
(NSPC )
changes in the stack.