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PLUMBING SYSTEM INSPECT DIAGNOSE REPAIR
AGE of PLUMBING MATERIALS & FIXTURES
AGE of CHIMNEYS & FIREPLACES
AGE of AIR CONDITIONERS & HEAT PUMPS
AGE of HEATERS, BOILERS, FURNACES
AGE of PIPING
AGE of WATER HEATERS
AIR DISCHARGE at FAUCETS, FIXTURES
AIR INLET VALVE, WATER TANK
AIR VOLUME CONTROLS, WATER TANK
ANTI SCALD VALVES
ANODES & DIP TUBES on WATER HEATERS
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER VALVE, HEATING SYS
BACKFLOW PREVENTER, HEATER WATER FEEDER
BACKUP PREVENTION, SEPTIC
BACKUP PREVENTION, SEWER LINE
BACKWATER VALVES, SEWER LINE
BOD WASTEWATER TEST
BLOCKED DRAIN REPAIR METHODS
BUILDING SAFETY HAZARDS GUIDE
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CHEMICAL CONTAMINANTS in WATER
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CHINESE DRYWALL HAZARDS
CHLORINE IN DRINKING WATER
CHLORINE IN SEPTIC WASTEWATER
CLEANOUTS, PLUMBING DRAIN
CLOGGED DRAIN DIAGNOSIS & REPAIR
CLOGGED SUPPLY PIPES, DIAGNOSIS
CLOGGED SUPPLY PIPES, REPAIR
CLOGGED SUPPLY PIPES, HOT WATER
CONDENSATION or SWEATING PIPES, TANKS
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DEPTH of DRAIN & SEWER PIPES
DEPTH of SEPTIC TANK
DIAELECTRIC PIPE FITTINGS
DRAIN & SEWER PIPING
DRAIN LINE DEPTH
DRAIN a WATER HEATER TANK
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOODED HEATING EQUIPMENT REPAIR
FLOODED SEPTIC SYSTEMS, REPAIR
FLOODED WATER HEATER REPAIR
FLOOR DRAIN / TRAP ODORS
FLUSHOMETER VALVES for TOILETS URINALS
GAS DETECTION INSTRUMENTS
GAS FIRED WATER HEATERS
GAS LP & Natural Gas Safety Hazards
GAS LP & Natural Gas Pressures
GAS PIPING, VALVES, CONTROLS
GALVANIC SCALE & METAL CORROSION
GALVANIZED STEEL PIPING
HARD WATER - SOFTENERS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
KITCHEN VENTILATION DESIGN
LEAD POISONING HAZARDS GUIDE
LEAK TYPES, Water Supply/Drain Pipe
MANUALS & PARTS GUIDES - HVAC
METHANE GAS SOURCES
MIXING / ANTI-SCALD VALVES
MIX VALVE SCALD PROTECTION, Best Practices
MUNICIPAL WATER PRESSURE IMPROVEMENTS
MOLD INFORMATION CENTER
MVOCs & MOLDY MUSTY ODORS
NOISE / SOUND DIAGNOSIS & CURE
NOISE CONTROL for HEATING SYSTEMS
NOISE CONTROL for PLUMBING
NOISE, PLUMBING DRAIN DIAGNOSIS
NOISE, PLUMBING DRAIN REPAIR
NOISE, PLUMBING CHECKLIST
NOISE, WATER HEATER
NOISES, WATER PUMP
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS IN WATER
ODORS, SEPTIC or SEWER
ODORS SEWER GAS in COLD WEATHER
ODORS, SULPHUR SMELL SOURCES
ANIMAL or URINE ODOR SOURCE DETECTION
OIL FIRED WATER HEATERS
OIL-FIRED BOILERS, HEATING
OIL FUEL TYPES & CHARACTERISTICS
OIL TANK PIPING & PIPING DEFECTS
OUTHOUSES & LATRINES
PIPING IN buildings, Clogs Leaks Types
PLASTIC PIPING ABS CPVC PB PEX PVC
PLASTIC PIPE INSTALLATION ERRORS
PLASTIC PIPE LEAK CAUSES
PLUMBING FIXTURES, KITCHEN, BATH
Plumbing Materials & Fixtures, Age, Types
PLUMBING NOISE CONTROL
PLUMBING VENT DEFINITIONS & CODES
PLUMBING VENT DEFECTS & NOISES
PUMPS, SEPTIC PUMPS
PUMPS, SEWAGE EJECTOR / GRINDER PUMPS
PUMPS, SUMP PUMPS
PUMPS, WATER PUMPS
PUMPS, WATER REPAIR
RELIEF VALVE LEAKS
REPAIR BURST LEAKY PIPES
SEWER GAS ODORS
SEWER LINE LEAKS & ODORS
SEWAGE BACKUP, WHAT TO DO
SEWER BACKUP PREVENTION
SEWAGE & SEPTIC CONTAMINANTS
SEWAGE CONTAMINATION in buildings
SEWAGE EJECTOR / GRINDER PUMPS
SEWAGE PATHOGENS in SEPTIC SLUDGE
SEWAGE PUMP CLOG DAMAGE
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SHUTOFF VALVE LOCATION, USE
SOUND CONTROL for PLUMBING
SULPHUR & SEWER GAS SMELL SOURCES
SUMP PUMPS GUIDE
SWEATING (CONDENSATION) on PIPES, TANKS
TANK TYPES: WATER, OIL, EXPANSION, ALL
TANKLESS WATER HEATERS
Temperature Pressure Relief Valves - Water Heaters
TOILETS, INSPECT, INSTALL, REPAIR
TOILET FLUSHOMETER VALVES
TOILET INSTALLATION PROCEDURE
TOILET OVERFLOW EMERGENCY
TOILET PLUGS, SEWER BACKUP
TOILET REPAIR GUIDE
TOILET TISSUE CHOICES
Toilet Types, Flush Methods
TOILETS, DON'T FLUSH LIST
TRANSITE PIPE WATER SUPPLY PIPING
TRAPS on PLUMBING FIXTURES
WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
WATER HEATER SCALE - De-Liming Procedure
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE & FLOW MEASUREMENT
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PRESSURE PROBLEM DIAGNOSIS TABLE
WATER PRESSURE PUMP REPAIR GUIDE
WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER PUMP REPAIR GUIDE
WATER QUALITY TESTS, CONTAMINANTS, TREATMENT
WATER QUANTITY IMPROVEMENT
WATER SHUTOFF VALVE LOCATION, USE
WATER SOFTENERS & CONDITIONERS
WATER SOURCE ALTERNATIVES
WATER SUPPLY & DRAIN PIPING
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TESTING ADVICE
WATER TEST CHOICES & WATER TEST FEES
WATER TEST INTERPRETATION
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WINTERIZE A BUILDING
Here we provide descriptions and photographs of unsafe gas piping, regulators, or controls on heating systems, indications of unsafe or improperly operating gas appliances, gas meters, and other gas installation defects. We also discuss the procedure for converting from LP gas or "bottled gas" to natural gas or "piped in gas" at a building.
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Immediate LP or natural gas safety hazards: if there is evidence of an LP or natural gas leak at a building, gas odors, for example, you should:
Heating equipment which the inspector (or building occupant or manager) judges to be an immediate life safety hazard should be shut down and appropriate emergency services called. See GAS LEAK DETECTION, LP / NG for leak detection procedures and alternatives.
Unsafe heating appliance conditions caused by backdrafting are discussed at BACKDRAFTING HEATING EQUIPMENT. This document also provides free sample draft home inspection report language for reporting defects in oil and gas piping at residential properties.
General safety warning: improper installation and even improper inspection and testing methods involving natural or "LP" gas can involve dangerous conditions and risk fire or explosion. If you smell gas you should leave the building immediately and should do so without doing anything that could create a spark such as operating a light switch or telephone.
From a safe location, call your gas company's emergency line and/or your fire department. The text provided here is a working draft and may be incomplete or inaccurate. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. Also see How to Report Defects in Oil Piping. NOTICE: while example report language is provided here, reproduction of this or any of our web pages or their contents at other websites or in printed documents for sale is prohibited.
What to Do if You Smell Gas
*** Immediate LP Gas or Natural Gas Safety Concerns:
Here is a list of examples of other immediate LP gas or natural gas leak safety hazards that might be detected using a TIF8800™ Combustible Gas detector or using a soap solution and bubble testing:
You should have your plumber test/replace any suspect gas controls promptly. Replacement of a control itself should not involve significant expense. This repair should not be deferred. You should be sure that building occupants know if this or other unsafe conditions are present.
Natural gas is supplied by the utility company through piping, usually buried in the street in front of or behind the building, and entering the building through a gas meter which is located outside or at older installations, possibly inside the building.
Our photo (above left) shows a gas meter installed indoors in a building utility basemen.
LP Gas or "bottled gas" or liquid propane gas is supplied (usually) by a local LP gas distributor who fills an LP gas tank located on and serving the building.
The LP gas tank may be above ground (usually at a building exterior wall) or it may be buried at the property. Our photo (left) shows a rather large outdoor aboveground LP gas tank.
Natural gas and LP gas appliance compatibility
These two fuels are similar in that both are used to provide energy to home heating systems and other appliances but they have some different properties of operating gas pressure, weight, method of distribution, and chemistry. Most gas appliances are delivered already set up to use either natural gas or LP gas but not both.
Most gas appliances can be converted from one fuel to the other - what is involved may be simply changing gas metering orifices in the equipment (for example at the burners on a stove) or it may also be necessary to change or adjust a gas regulator located inside the appliance.
Watch out: Do not hook up an LP gas-ready appliance to a natural gas supply nor can you connect a natural-gas ready appliance to an LP gas supply without reviewing and acting on the manufacturer's instructions for converting the appliance from one fuel to the other. It is virtually always the case that some equipment adjustments and changes are necessary to switch between natural gas and propane gas.
As JR, an industry manager familiar with gas pressures pointed out, these two fuel gases operate at different pressures. In residential appliances
If you are planning to convert from one gas fuel to another, such as from LP gas (bottled gas or liquid petroleum gas) to piped in natural gas, see our advice and safety warnings at Gas Conversion LP Natural Gas.
What Chemicals are Used to Produce the Characteristic Odors in Natural or LP Gas?
Mercaptan gas odorant components, concentration strength, human exposure levels
Mercaptan is, according to our industry commentator J.R., a widely-recognized odorant, but only one of a number of similar-smelling products that are added to natural gas or bottled gas to assist in recognizing that a dangerous gas leak is present since natural gas alone, CH4 (Methane) is odorless.
The product added to natural gas to provide it with a characteristic odor is a mixture of tertiary butyl mercaptan, dimethyl sulfide and n-hexane.
Commonly in the trades the gas odorant product is just called "mercaptan".
Mercaptan is added to natural gas at a rate of 0.08cc’s/1.0 m3 of natural gas.
Therefore very little mercaptan (or other gas odorant chemicals) in the gas stream.
Gas odorants are produced by Odor-Tech, a subsidiary of Arkema, by Chevron Phillips Chemical, and others. Odor Tech also produces Mercaptan Assassin ESD - an odorant-blend kit used to clean up mercaptan spills.
Critical Hazard Limits for Natural Gas or LP Gas
According to J.R., one of our industry correspondents, odorants need to be detectible in the natural gas at 1/5 the lower explosive limit (LEL), or more properly, the lower flammable limit or LFL.
So this is the amount of natural gas required in the test.
A person is exposed to very little natural gas in the air by the time they smell it.
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Frequently Asked Questions (FAQs)
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