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PLUMBING SYSTEM INSPECT DIAGNOSE REPAIR
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AIR DISCHARGE at FAUCETS, FIXTURES
ANTI SCALD VALVES
ANODES & DIP TUBES on WATER HEATERS
BACKUP PREVENTION, SEPTIC
BACKUP PREVENTION, SEWER LINE
BACKWATER VALVES, SEWER LINE
BATH & KITCHEN DESIGN GUIDE
CHEMICAL CONTAMINANTS in WATER
CHEMICAL ODOR SOURCES
CHLORINE IN DRINKING WATER
DEBRIS in WATER SUPPLY, Water Heater
DEPTH of SEPTIC TANK
DRAIN & SEWER PIPING
FAUCETS & CONTROLS, KITCHEN & BATH
FAUCETS, OUTDOOR HOSE BIBBS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOR DRAIN / TRAP ODORS
FLUSHOMETER VALVES for TOILETS URINALS
GAS PIPING, VALVES, CONTROLS
GALVANIC SCALE & METAL CORROSION
HARD WATER - SOFTENERS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
LEAD POISONING HAZARDS GUIDE
LEAD IN DRINKING WATER, HOW to REDUCE
METHANE GAS SOURCES
MIXING / ANTI-SCALD VALVES
MUNICIPAL WATER PRESSURE IMPROVEMENTS
NOISE / SOUND DIAGNOSIS & CURE
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
PIPING IN BUILDINGS, Clogs Leaks Types
PLUMBING FIXTURES, KITCHEN, BATH
PLUMBING NOISE CONTROL
PLUMBING VENT DEFINITIONS & CODES
PLUMBING VENT DEFECTS & NOISES
PUMPS, WATER REPAIR
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - STEAM TP VALVES
RELIEF VALVES - Water Heaters
RELIEF VALVES - Water Tanks
REPAIR BURST LEAKY PIPES
METHANE GAS HAZARDS
SEPTIC SYSTEM INSPECT DIAGNOSE REPAIR
SHUTOFF VALVE LOCATION, USE
SULPHUR & SEWER GAS SMELL SOURCES
SWEATING (CONDENSATION) on PIPES, TANKS
TOILETS, INSPECT, INSTALL, REPAIR
WATER, WELLS, WATER TANKS: TESTING GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMPS & TANKS
WATER SOFTENERS & CONDITIONERS
WATER SOURCE ALTERNATIVES
WATER SUPPLY & DRAIN PIPING
WATER SHUTOFF VALVE LOCATION, USE
WATER SHUTOFF VALVE, WELL PUMP
WATER TESTS, CONTAMINANTS, TREATMENT
WELLS CISTERNS & SPRINGS
WINTERIZE A BUILDING
Copper plumbing, copper supply & copper drain pipes: this article lists our in-depth articles on inspecting, testing, and repairing problems with copper plumbing: water supply and drain waste vent piping, plumbing traps, piping materials, clogged or noisy pipes, and types of pipe hazards or product defects. The articles at this website will answer most questions about water supply & drain piping, wells, & water tanks as well as many other building plumbing system inspection or defect topics.
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Types of Copper Piping used in buildings
Our page top photograph shows a remarkable method used by a homeowner to handle leaks at a poor solder joint on copper water supply piping.
Our photograph of copper water supply piping (left) tells us that this is a cold water supply line located in a humid or wet crawl area - notice the condensation on the piping? More about "sweating" cold water pipes is at CONDENSATION or SWEATING PIPES, TANKS.
The following summary notes about copper and other types of building piping are from Carson Dunlop Associates' Home Reference Book, used with permission:
Copper piping has been used extensively since the early 1950s for supply lines from the city main to the house as well as for in-building water supply and drain piping.
Copper water supply piping is typically 1/2 or 3/4 inch diameter. Copper piping is typically 1/2 or 3/4 inch diameter. Copper piping has soldered connections and the walls of the pipe are thinner than galvanized steel. Copper piping has soldered connections and the walls of the pipe are thinner than galvanized steel.
From 1950 to 1970, 1/2-inch diameter piping was used commonly for residential building water supply pipes. After 1970, 3/4-inch diameter copper service piping has been more common for building water supply piping.
Guide to K, L, and M and Other Types of Copper Pipes used in Buildigns: life expectancy, izes, thickness, durability & uses
The life expectancy of copper piping is dependent on water conditions.
In many areas, its life expectancy is indefinite. In harsh corrosive water or corrosive soil conditions, it may fail within 20 years or even less.
Occasionally manufacturing defects also result in early failure of copper building piping. We discuss water pH, acidity and corrosiveness at Copper Piping FAQsbelow.
Carson Dunlop Associates' sketch (left) illustrates three types of copper piping used in buildings for water supply or drains. In order of thickness, from thinnest to thickest pipe walls, read Types M, L, or K copper.
How is Copper Piping Sold: lengths, diameters
Copper piping is sold in nominal or standard sizes in straight lengths of 12 ft. 18 ft. or 20 ft. from 1/4" diameter all the way up to 12-inches in diameter, depending on the copper type, thickness, grade, and intended application. Copper piping from 1/4" up to 2-inch in diameter is also sold in coils of 45' up to 100 ft. depending on the pipe diameter.
What is the Relationship Between Nominal Copper Pipe Size and its Actual Physical Size?
Copper piping discussed here and used for plumbing is 1/8" larger in diameter than its nominal diameter. So a 1/2" copper pipe will actually measure 5/8" in thickness. The actual internal diameter of a copper pipe will vary depending on the thickness of the pipe wall, even though these outside dimensions remain the same. For example, because K-copper has a thicker tube wall than Type M copper, a 1/2" K-copper pipe will have a slightly smaller inside diameter than a 1/2" L or M copper pipe.
Refrigeration Tubing Copper
Unlike copper used for plumbing (above), copper tubing used for HVACR (heating, ventilating, air conditioning & refrigeration systems), is sold in sizes that correspond to the actual outside diameter of the tubing.
The copper content of copper piping meeting the ASTM standards below is virtually pure copper - or 99.9% Cu. The copper is shiny when purchased, typically having had any exterior or interior surface oxidants cleaned off using phosphorous. If you hear reference to DHP copper or C122 coppeer, this is the product being described.
The four most-relevant standards for copper pipe thickness and dimensions depend on the intended application and use and are listed as follows:
Flexible copper tubing is usually joined to additional tubing sections or to other plumbing fittings by either compression fittings or flare fittings, depending on the application.
For example, compression fittings (photo at left, from Wikipedia) are sometimes used on copper water piping where soldering is difficult or inconvenient, but these are not used on copper gas or oil lines where flare fittings may be applied instead.
Flare fittings and compression fittings are intended for use on soft-temper copper piping and tubing. In addition to flare and compression fittings there are also other mechanical connectors that now work with soft or hard copper that do not require soldering.
Watch out: compression fittings are very convenient and easy to install on copper pipes or copper tubing, but if you fail to de-burr a freshly-cut copper pipe or tube, properly ream out the interior opening, or if you over-tighten the coupling during installation you may crack the brass or copper ring, leading to leaks at the connector.
Compression fittings are used with K-copper. K copper pipes and tubing can also be joined or connected using flare fittings and sweat fittings discussed below.
Flare fittings used on flexible copper piping and their leaks and defects are discussed at GAS LEAK DETECTION, LP / NG and GAS PIPING DEFECTS. Using a special flaring tool the soft copper tubing or piping is actually spread open or flared at its end in order to mate with the female end of the flare fitting connector shown in our photograph.
Watch out: defects in flare fittings used on flexible copper tubing can result in gas leaks out of gas piping, and in the case of oil piping such as for oil-fired heaters, flare fitting defects result in both oil leaks out of the system and air leaks into the system. Air leaks into oil piping in turn lead to improper oil burner operation and even potentially dangerous conditions. Flare fitting defects include:
Seat and flare fittings are permitted on K and L copper. LP gas tubing. These fittings are not used on refrigeration equipment.
Soft copper tubing can also be joined by using a swaging tool that expands the open end of one of the tubes to be joined so that its mate can be inseted into the enlarged opening, and the result sealed by soldering or brazing.
This is a common procedure when using air conditioning refrigerant tubing because of the high pressures that may be involved and the need for extra strong resistance to leaks in piping that may be subject to wide temperature variations as well as mechanical vibration.
Our photo (red arrow in photo at left) illustrates swaged fittings on copper tubing - you can see the swaged tubing joints at the left and right ends of the gray filter-dryer on this air conditioning high pressure refrigeration line exiting at the bottom of a compressor-condenser unit.
A swaging tool is inserted into the end of the copper tube and hammered inwards. As the properly-calibrated diameter of the swaging tool is forced into the copper tube, the copper expands to just the right size to accept the outer diameter of the mating section to be inserted. For example, if we are swage fitting two sections a 3/8" nominal diameter copper tube together, the swaging tool will enlarge the receiving copper tube section so that its inside diameter will accept the 3/8" outer diameter of the un-treaterd tube to be joined.
Usually we work the swaging process on tubing at ambient temperatures but some procedures call for pre-heating the copper to make it easier to expand.
Watch out: Soft copper tubing is drawn copper while hard tubing is annealed. It's easy to swage fit soft copper, usually. But if copper tubing has been repeatedly bent, that process may have annealed the copper somewhat, making it difficult to form either a flare fitting or a swaged fitting without cracking the tubing. Copper tubing may also become crack prone when exposed to mercaptan or other odorants in LP gas or natural gas. Moisture exposure and even some types of solder also can affect its susceptability to cracking later. For these reasons copper tubing is not allowed for natural gas distribution.
"Sweat" fittings or "soldered fittings" for copper piping refer to the traditional and perhaps most widely-used method for residential copper suppy and drain pipe connections, bends, elbows, valves, and similar fittings in buildings.
Depending on the connection required, a coupling (straight connection), 90 degree ell, 45 degree ell, tee, and even fittings that marry copper pipes of different diameters are soldered to the copper tubing or pipe to make the connection.
Sweat fittings may themselves be made of copper tubing that has been formed by machine, or from cast or milled bronze.
Watch out: on older buildings brass water supply piping may have been used, and may be at or near the end of its useful life. It can be tricky to tell the difference between brass water supply piping and copper water supply piping if you are not experienced with these materials, as their colors are similar, especially when both types of piping have become an oxidized brownish color with age.
Both brass and copper are non-magnetic, so they won't respond to a "magnet" test to look for iron or steel.
Brass water supply piping, unlike copper, is a thicker material that is usually joined by threaded fittings of the same size and pipe thread specifications (NPT) as iron and galvanized iron piping.
Usually, brass piping is also so rigid that it is not bendable. Or not very bendable anyway. So in our photograph (left) of water supply piping at a bath tub in an older home, the larger-diameter left-hand pipe is surely brass, connected to a galvanized iron fitting at its bottom end. The right-hand vertical pipe may be copper tubing as is the darker copper pipe at left behind our brass one.
Don't worry about that odd little machine in bottom center of the photo - we were collecting an air sample in this wall cavity.
Water chemistry, Electrical Grounding, Netural Wiring, & Copper Pipe Pinholing & Leaks
In a building where leaks are found recurrent in copper piping there are several possible explanations:
some possible causes for the pinhole leak in copper water piping under your building slab.
Summary of the issue around grounding building water piping
Many sources, including the Connecticut DOH have pointed out a long-standing disagreement & confusion about the reasons for grouinding building water supply piping. For example
This statement is a bit of a red herring. Water and some plumbing associations are concerned about building owner complaints about metal water supply pipe corrosion and leakage that might be traced to or blamed on the electrical grounding of those systems. Wishing to avoid those complaints the industry, under the aegis of warning that water suppliers can't be responsible for the failure of such an electrical ground [a valid caveat] a warning is issued that also gives relief for metal piping leaks caused by a variety of other problems such as
More to the point, metal water piping is grounded not to provide an electrical ground for the building (we agree completely that water piping as a ground is unreliable for many reasons, (such as inclusion of non-conductive plastic piping, diaelectric fittings, water meters, etc). Metal water piping is bonded to a building ground system as an important safety precaution to protect building occupants from electrocution hazards should live electrical wires or components come in contact with buidling piping, faucets, fixtures, etc.
In a properly-wired building, the grounding conductor and bonding system do not normally carry current, and would not be blamed for copper pipe pinholing etc. The grounding system is intended to conduct electrical current only in the event of a fault or emergency [such as a lightning strike or a hair dryer dropped into the bath tub or sink].
Details about the code requirements and reasons for grounding metal water piping are at WATER PIPING GROUND BOND
How to Check for Electrical System Problems that Corrode Copper Water Pipes
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Frequently Asked Questions (FAQs)
Question: Acidic water & copper pipe corrosion/leak risk: Sage advice needed -- I have fairly acidic well water on Cape Cod – pH 6.3.
I get a lot of blue stains on bathtubs and sinks, which I assume is copper leached from the inside of the copper water-supply piping. I built the house about 16 years ago and replaced the water heater a few years ago.
Am I at risk of developing pin holes or other damage to the copper plumbing and other equipment, including an electric water heater, boiler, and baseboard radiation?
If that’s the case, what’s the preferred (and cheapest) solution: calcite neutralizer tank, soda ash feeder, or other?
FYI, copper level was last measured at 0.11 mg/L, well below the MCL of 1.3, so I don’t think there’s a health issue. But I figure if copper gets leached from the pipes for enough years, at some point there won’t be much pipe left.
Muchas gracias, Steven Bliss, 4 Burlington, VT
I do not have experience with pH treatment first hand, but it appears to me that the short answer is that for most situations, calcite filters are the easiest and cheapest method of treatment. But certainly experts have been looking at this problem for along time, and continue to research it. See Mattsson et als .
Before choosing one I'd measure the Langelier Saturation Index (LSI) of the water so you can figure out the level of treatment needed and check that against the treatment method proposed.
Incidentally, before water testing or asking your test company about what they commonly find in wells in your area of Cape Cod, don't rule out the water supply itself as contributing to the supply of dissolved copper. You could easily distinguish between copper from acidic effects on copper water piping and copper in the water supply by comparing two water tests, one taken from in the building (I give some aggressive testing suggestions below) and one taken from water where it enters the building, presumably through a plastic or galvanized iron well pipe (not a copper one).
Until you know the score, if there is a worry that pipes may already be thin or at risk, that's an extra reason to shut off water when leaving the property unattended. Some of the suggestions at WINTERIZE A BUILDING might help.
Acidic Water Treatments: Calcite Filters vs. Soda Ash Injection
According to the Clean Water Systems & Stores (who sell this equipment) , calcite neutralizer filters
More sophisticated is a soda ash injection system. That approach requires a pump and metering device along with an intermediate tank to give the water enough contact time with the soda ash. And room to store 25 or 50 pound bags of soda ash. Like some other water treatment systems (like a chlorine injector) the soda ash injector pump is hooked up to run when the well pump turns on. It seems that a soda-ash injector system is recommended when the low pH of water is due to dissolved mineral acids (do you live near a mining site or in New York a natural gas from shale mining operation?).
On acidic well water and water corrosivity - Definition of the Langlelier Saturation Index
It's true that the lower the pH (more acidic) the higher the level of corrosivity of the water supply. But because pH is only one of several factors that will determine how corrosive the water is, while we should look at acidity or pH, if you want to know how worried to be about your water supply corroding your pipes, you want to perform a corrosivity test on your water.
But looking at building water supply properties and pipes and fixtures for evidence of what contaminants or water chemistry problems may be present can be confusing. Our faucet outlet (photo at left) shows both thick white mineral deposits (suggesting high calcium and high pH) and blue/green stains and deposits that might to some suggest acidic water and low pH.
While there is no doubt your water is
Experts us the Langelier Saturation Index (LSI) to estimate the corrosivity of a water supply. The Langelier Saturation Index or LIS is a number calculated from several factors and intended to tell you the chances that minerals, principally calcium are likely to precipitate out of the water.
Langelier, who developed this index, realized that the acidity or pH of water determines how much calcium carbonate CACO3 the water can hold. So a combination of the water's actual pH and the actual level of calcium in the water, along with other factors we list below, allow us to predict the chances that the water will leave scale in the plumbing system or components by precipitating out the calcium. We think of it as a more complete picture of water chemistry, with regards to both hardness (mineral content) and acidity or pH.
The Langelier calculation factors in the main components of corrosivity of a water supply including:
Action Levels in the Langelier (LSI) Index
The Langelier index, when calculated ranges from +4 through 0 to -5. But you don't have to calculate anything. Just ask your water test company to perform this test for you, OR ask the water test company to test your water for hardness (you can do this free or cheap at MEASURE WATER HARDNESS ) and for corrosivity.
+4 LSI = scale producing water: At +4 the water is very likely to form scale deposits in the piping, especially hot water piping or in a water heater. Readers whose water is hard and/or has a high positive Langelier index should see WATER SOFTENERS & CONDITIONERS.
Zero LSI = just right: like the baby bear who found one of the porridges "just right", At an LSI of zero the water supply is "neutral" - it is not likely to precipitate calcium into the piping nor is it acidic enough to dissolve more calcium. With respect to the corrosive effects of acidic water on copper water piping, an LSI of zero also means the water is close to ideal - it is not corrosive to the piping.
At -5 LSI = corrosive water: at -5 LSI the water is extremely corrosive. Langelier index values of +0.5 to -0.5 are basically OK in that you wouldn't treat water at those levels.
If you decide to treat the water based on acidity alone or based on a Langelier index reading of -3 or lower (or optionally anywhere below -0.5) there are various systems that inject something basic like calcite (a calcite neutralizer tank or calcite neutralizer filter) or soda ash (a soda ash feeder) to treat the water and described above.
Other indices of water condition include the Ryznar Stability index that predicts water chemistry and how it will affect piping and appliances by examining the thickness of scale formation in municipal water systems, the Puckorius scaling index, the Larson-Skold index, the Stiff-Davis Index, and the Oddo-Tomson Index.
Inspect your copper piping for evidence of leaks, corrosion, pinholes & leak risk factors
First, what quality of copper has been installed. Copper piping is sold in different weights or thicknesses. M is thin-walled, used in heating baseboards (you should be ok with that as the water in a hot water heating system does not keep changing out so corrosivity is normally limited); Types K (thickest) and L are used for water piping, M being the heavier grade, more resistant to corrosion perforation.
Therefore if your distribution piping is Type L you should inspect for corrosion on the pipe exterior - and beware that a small blue dot, when you scratch it, may become a rapid leak. Don't ever "pick" at corrosion unless you're prepared to shut down the water supply and clean up a leak. The bad news that has come up with some InspectAPedia readers, is that if you discover a length of copper piping with imminent or current pinholes, replacing just that section is not very comforting. Because the piping is corroding from the interior out, you won't see how thin and fragile other piping sections are ... until the next leak.
Also, corrosive water combined with waste and waste water risks corroding copper drain piping. Surprisingly you need to look along low-sloping runs of copper drain piping for evidence of corrosion or leaks along the top of the pipe, not just the bottom. It appears that droplets of highly corrosive condensate form along the upper surface of the pipes and remain in place for long periods, never being washed away by drain usage.
The World Health Organization, WHO, in discussing water pH, says
Exposure to extreme pH values results in irritation to the eyes, skin, and mucous membranes. Eye irritation and exacerbation of skin disorders have been associated with pH values greater than 11. In addition, solutions of pH 10–12.5 have been reported to cause hair fibres to swell (10). In sensitive individuals, gastrointestinal irritation may also occur.
Exposure to low pH values can also result in similar effects. Below pH 4, redness and irritation of the eyes have been reported, the severity of which increases with decreasing pH. Below pH 2.5, damage to the epithelium is irreversible and extensive (10). In addition, because pH can affect the degree of corrosion of metals as well as disinfection efficiency, it may have an indirect effect on health.
In addition, if well water at a particular building also happens to require disinfection, the pH is important and needs to be below 8.
What is the Optimum pH for a Building Water Supply?
WHO says in general the optimum pH target for drinking water should be 6.5 - 9.5, adding " No health-based guideline value is proposed for pH." [but they didn't appear to consider the effects of dissolved copper - if it occurs]
Other Causes of Pinhole Leaks in Copper Pipes in Buildings
Other causes of copper pipe pinholing or holing and leaks include
We joined in investigating a site that had suffered what appeared to be a lightning strike - it was actually an electrical discharge from a high voltage power transmission line. A tree grew tall enough to contact the line, conducting power to the ground close to the home. Moisture under the garage floor slab vaporized, exploding the floor, sending the car up through the garage roof.
Electricity traveled across from the garage, apparently following tree roots, up an iron entry stair railing, over to aluminum siding (all the aluminum pop rivets melted and all of the the siding corner trim pieces fell to the ground), around the siding to a metal outdoor hose bib to metal water piping. Inside the building the water pipe was fused and melted, causing a basement flood.
Electrical Ground Wiring Errors Can Cause Plumbing Pipe Leaks
Watch out: also to check for electrical system connections that can significantly increase the risk of corrosion of the copper piping in the building. As you know, at most buildings the water piping system is grounded for safety, and sometimes a metal well pipe extending outside underground is used as a grounding electrode as well. Electricians recommend two driven grounding electrodes at modern properties (you can leave the old connection to a metal well pipe in place).
But interestingly, a mistake in the electrical panel, for example one that sends current improperly down the ground path, can speed up corrosion of building metal water pipes or other components.
I had a client in Pleasant Valley NY who twice replaced a very costly, supposedly corrosion proof nickel-plated co-axial ground-water-source heat pump temperature exchange coil. The purpose of the coil was to cool high temperature refrigerant gas back to a liquid state by cooling it using water pumped from a nearby well and for efficiency recycled through a holding tank for re-use before it was returned back to the ground from which it had originated.
When the heat pump stopped working I found that all of the refrigerant had leaked out of the system. But I couldn't find a leak in the refrigerant piping system. The only component I could not test directly with my halogen leak detector was the water-to-air heat exchanger coil itself. In an exciting discovery, I opened a drain to release water from the water-to-air heat pump system's water reservoir tank.
When I held my leak detector near the water stream, the detector went crazy, responding to a very high level of refrigerant gas that had become dissolved into the water.
We realized that the heat exchanger coil that was supposed to just cool the refrigerant gas was instead leaking that gas right into the cooling water supply.
Someone smarter than we were figured out where to look. The technician determined out that the heat exchanger coil was corroding and perforating because of improper electrical grounding within the heat pump.
Recommended Maximum Limits for Copper in Drinking Water
EPA's list of limits on contaminants in water (http://water.epa.gov/drink/contaminants/index.cfm#List) is set in MCL (Maximum Contaminant Level), MCLG (Maximum Contaminant Level Goal) or mg/L (milligrams per liter) (mg/L === ppm) or parts per million - two ways of describing the same concentration
For copper EPA recommends both a MCLG and an "action level" of 1/3 mg/L for copper in drinking water, citing short term gastrointestinal distress (short term exposure) or liver or kidney damage (long term exposure). EPA also warns " People with Wilson's Disease should consult their personal doctor if the amount of copper in their water exceeds the action level"
Test the level of copper in your water - how to construct a "worst case" test
It would be instructive to test your water's copper content to see if it's unusually high. Not only would that tell us if acidic well water is corroding the pipe interior, you might find that the levels of copper are high enough to merit action for water safety / potability.
Making a "worst case" (most critical or "safest") measurement for copper or any other contaminant that might be found in drinking water due to dissolving the contaminant out of the water piping and supply system equipment can be done following the DF approach. We want to collect a sample of water that is most likely to represent the highest concentration likely to occur in household water that someone might drink.
To construct the "worst plausible case" scenario we collect a water sample after water has been sitting in the pipes for some time period. A longer wait period (days, weeks, months) might represent a house that has sat unoccupied for some time. But in my opinion I'd collect water that has sat overnight as a more likely and thus more plausible "worst case" scenario.
If all of the house plumbing is copper, you would, on "the morning after", go to a plumbing fixture most distant from the incoming water supply, pump, and tank, open a cold (test 1) water faucet and run enough water to flush out the faucet and any plastic fixture risers, so that we're sure we've got water that was in the copper piping overnight. Then collect the sample.
Watch out: at WATER TESTS, CONTAMINANTS, TREATMENT we discuss testing well water quality - what is "in" the well water that may make it unsafe or unpalatable to drink. Water that may be too high in mineral content, clogging pipes and water heaters (see MEASURE WATER HARDNESS), or water that is too acidic or corrosive, causing leaks in copper piping (see CORROSIVITY or ACIDITY of WATER). And at least as important is the question is "does the well provide enough water" - a topic discussed at WELL FLOW RATE and at WELL QUANTITY FLOW TEST PROCEDURE
Hot water and water pH - what happens to pH when we heat up the water?
You could collect a hot water sample as well, running water until it's hot, but because the "hot" water has arrived fresh from the water heater tank, it has not sat overnight in the piping and so is not such an aggressive test - I wouldn't bother. Not unless your home uses an antique copper water heater tank.
The WHO guidelines for drinking water quality points out some interesting technical detail,including that (at least for pure water) heating the water will decrease the water's pH. A pH decrease of 0.45 occurs when you raise water temperature by 25 deg. C. 
If the house has part plastic water supply piping, you'd want to see where the copper is located, calculate (by linear feet of pipe and its diameter) how much cold to run out to be sure you've collected a sample from inside the copper pipes.
That about exhausts me on copper pipes, pH, corrosion, copper testing, Langelier index, and treatment for low pH water. Thanks for asking.
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Technical Reviewers & References
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