DIY Plumbing Tips: Fix Pipe Leaks

Copper is the most commonly used plumbing material in the United States today, installed in more than 80 percent of all homes and office buildings in the U.S. Relatively inexpensive and easy to use, and known for its resistance to contamination and corrosion, copper is used for pipes and numerous other plumbing fixtures. Unfortunately, however, notwithstanding excellent resistance, copper pipes are not immune from springing leaks over time, resulting in costly damage.

The most common reason for a copper pipe to leak is due to pitting, a form of corrosion that occurs in both soft water and hard water environments, and attacks small, localized areas on the inside wall of the pipe. While much research has been conducted in this area, the exact reason why pitting type corrosion occurs remains unknown. It is, however, generally believed to be due to a chemical reaction between the water and the copper, and has been classified into one of three categories (Type I, Type II, and Type III Pitting) based on water temperature and pH level. Type I occurs place in cold, hard water with average pH levels between 7.2 and 8.0. Type II occurs at in warm, soft water with pH levels that are less than 7.2. Type III occurs in water that is cold, and soft with high pH levels. A pinhole leak occurs as the final stage (and breakthrough) of an area of the pipe affected by pitting.

A second reason why a copper pipe may leak is the use of poor quality materials in building, such as a builder using lower grade copper, or pipes of a smaller diameter than necessary.

A third reason for leaking copper pipes is that, in installation, plumbers sometimes take shortcuts that compromise the pipes. One example is a technique known as "cold bending" in which, rather than using elbow joints, the plumber simply bends the pipe to make turns. At the bend, the copper is weakened and over time, water will cause the pipe to erode, eventually resulting in leaks.

While the second and third reasons stated above can (and should) be eliminated in the building and plumbing installation process, it is, unfortunately, virtually impossible to prevent or stop copper from pitting. By taking the following steps, however, it is possible to reduce damage caused by the leaks induced by such pitting:

Check all copper piping that is exposed for small stains of a bluish-green color, which is one potential sign of a pinhole leak. Upon first noticing any such leaks, call a licensed plumber immediately to determine if there is, in fact, a leak. Note: Such bluish-green stains can also be found on copper pipes in damp environments, such as basements, so such stains do not necessarily indicate a leak.

Purchase pipe clamps, and install over pinhole leaks, until a plumbing contractor can perform a more permanent repair. Such clamps are available for purchase at any hardware or home repair store.

Unfortunately, however, other than replacing the damaged section of the pipe completely, a job best left to a licensed plumber, there is no permanent solution to a pinhole leak resulting from pitting corrosion. Nor are there any certain prevention techniques to keep such pitting from occurring in the first place.

Cast Iron Waste Pipes

here's a crack about 8" long on the top of the large iron sewer line that runs through my basement. The surface of the pipe has some brownish-orange rust, but it seems to be a very thin coating. Before I call a plumber, I'm trying to do some research to determine if this is a sign that the entire piping system might need replacement. How long do these pipes last? Any insight would be appreciated.

About a dozen US cities possess cast iron pipes that have supplied water for over 150 years. Hundreds have cast iron water mains over 100 years old. Cast iron pipes used for waste piping, however, are subject to corrosive action that pipes carrying drinking water are not.

The external rust, unless showing deep pitting, is common and probably not a concern. I've heard of only a few cases of underground waste lines failing from external corrosion as a result of being in contact with unusually acidic soil. When cast iron waste pipes fail, it's usually due to corrosion from within.

As a result of what runs through waste lines, hydrogen sulfide gas can form. This can oxidize and produce sulfuric acid, which corrodes cast iron. Some drain cleaners also contain sulfuric acid and, if used continuously, can accelerate the corrosive action and shorten the life of the cast iron piping system.

When examining cast iron piping, you'll typically find two different signs of failure. One is the crack that you describe, usually forming on top of the pipe or at a seam, created by the form used during the casting process. This is likely due to the hydrogen sulfide gas collecting in concentration and the resulting acidic attack weakening the pipe wall.

The other external indication of failing cast iron pipes is blobs of rust, usually found on the underside of horizontal sections. The size of these blobs can be anything from little pimples to about the size of half a walnut shell. These aren't as obvious as cracks and can be overlooked because they don't perpetually leak. As the iron around a pinhole rusts, the iron expands and seals the leak. While they might not be actively leaking when discovered, it's certainly a sign that internal corrosion has breached the wall of the pipe.

The old method of casting pipes, called the "pit-cast" method, can leave variations in the thickness of the pipe walls. The thinner-walled portions might be the first to show cracks or pinholes, but there are likely other areas of corrosion that just haven't surfaced--yet. Although more common, this corrosion isn't limited to the horizontal sections. Cracks, pinholes and rust blobs can appear on vertical sections as well.

Some homeowners, and occasionally some professionals, insist that patching a pipe that has cracked or developed a pinhole is an acceptable and permanent repair. Based on my experiences, I disagree. I recommend the section of pipe showing any sign of failure be removed and replaced by an experienced plumber. While the repairs are being performed, the adjacent sections can be evaluated. If the walls are getting thin from corrosion, removal and replacement of these sections is advised.

Pitting Corrosion on Metal Surface

Pitting is one of the most destructive forms of corrosion as it will potential cause equipment failures due to perforation / penetration. pitting generally occurs on metal surfaces protected by oxide film such as Stainless steel, aluminum, etc. Typically for boiler and feed water system, pitting corrosion rate increase dramatically with the increase of oxygen content in the fluid.

Pitting can occur in any metal surfaces. Following are some pictures of pitting corrosion.

BASIC INFORMATION about pipe

• The majority of ships’ pipes are made of mild steel.

• Flow rate, viscosity and pressure of fluid being carried

determine a pipe’s diameter.

• Pipes in areas of a ship where there is a risk of gas explosion

are earthed because fluid flow can build up a static electricity

charge. Bonding strips are used across flanged joints to

maintain conductivity.

• Pipes that pass through other compartments pose potential

subdivision issues, especially open-ended pipes.

• Pipes, especially open-ended ones, compromise the integrity

of the compartments they pass through.

• The water circulating in cooling pipes will corrode them over

time.

• Pipes passing through tanks containing liquid are exposed to

corrosive attack on both surfaces.

• Pipes carrying liquefied gas seldom suffer internal corrosion.

• Visual checks of the external surfaces of a pipe will not indicate

its condition because it could be internally corroded and have

a reduced wall thickness.

• Most abrasive corrosion and consequent internal thinning

happens where the pipe bends and at elbows.

• Liquid flowing quickly will be turbulent as a result of fluid

separation and cavitation. Flow turbulence in a pipe will

cause pitting. A pipe with the correct diameter for the job

will eliminate turbulence.

• Pipes can be joined by butt-welding, with flange connections or

mechanical joints. However, the number of flange connections

allowed in the cargo pipes of a chemical tanker is strictly

controlled by classification society rules.

• Good pipe alignment during assembly of a run prevents

‘locked-in’ stress.

• The use of expansion (mechanical) joints, such as dresser-type

joints, is restricted to locations where pipes move because of

thermal expansion or contraction, or ship bending. Classification

society rules prohibit their use for the connection of cargo piping

in chemical tankers. The most common expansion joints are

compression couplings or slip-on joints.

• A pressure test of 1.5 times design pressure is a strength test;

a test at the design pressure is a tightness test. Pressure testing

can show the small cracks and holes that will not be found by a

visual examination.

• Pipes are held in place by supports or clips that prevent

movement from shock loads and vibration. Pipe failure is

common when pipes are allowed to vibrate.

• Pipes carrying flammable liquids have as few joints as possible

and these are shielded to prevent leaks from coming into

contact with hot surfaces.

• Mechanical joints are not normally fitted on pipes carrying

flammable liquids.

Cold water pitting of copper tube - Precision Fasteners - Sheet Metal cabinet

Copper water tubes Copper tubes have been used to distribute potable water within building for many years and hundreds of miles are installed throughout Europe every year. The long life of copper when exposed to natural waters is a result of its thermodynamic stability, its high resistance to reacting with the environment, and the formation of insoluble corrosion products that insulate the metal from the environment. The corrosion rate of copper in most potable waters is less than 25 m/year, at this rate a 15 mm tube with a wall thickness of 0.7 mm would last for about 280 years . In some soft waters the general corrosion rate may increase to 125 m/year, but even at this rate it would take over 50 years to perforate the same tube. Despite the reliability of copper and copper alloys, in some cold hard waters pits may form in the bore of a tube. If these pits form, failure times can be expected between 6 months and 2 years from initiation. The mechanism that leads to the pitting of copper in cold hard waters is complex, it requires a water with a specific chemistry that is capable of supporting pit growth and a mechanism for the initiation of the pits. Pitting The pits that penetrate the bore are usually covered in a hard pale green nodule of calcium carbonate. If the nodule is removed a hemispherical pit is revealed filled with coarse crystals of red cuprous oxide and green cuprous chloride. The pits are often referred to as Type 1 pits and the form of attack as Type 1 pitting. Water The characteristics capable of supporting Type 1 pits were determined empirically by Lucey after examining the compositions of waters in which the pitting behaviour was known . They should be cold, less that 30C, hard or moderately hard, 170 to 300 mg/l carbonate hardness, and organically pure. Organically pure waters usually originate from deep wells, or boreholes. Surface waters from rivers or lakes contain naturally occurring organic compounds that inhibit the formation of Type 1 pits, unless a deflocculation treatment has been carried out that removes organic material. Type 1 pitting is relatively uncommon in North America and this may be a result of the lower population density allowing a significant proportion of the potable water to be obtained from surface derived sources. In addition to being cold hard and organically pure, the water needs a specific chemistry. The effect of the water chemistry can be empirically determined though use of the Pitting Propensity Rating (PPR) a number that takes into account the sulfate, chloride, nitrate and sodium ion concentrations of the water as well as its acidity or pH. A water with a positive PPR has been shown to be capable of propagating Type 1 pits. Initiation Many waters in both the UK and Europe are capable of supporting Type 1 pitting but no problems will be experienced unless a pit is initiated in the wall of the tube. When a copper tube is initially filled with a hard water salts deposit on the wall and the copper slowly reacts with the water producing a thin protective layer of mixed corrosion products and hardness scale. If any pitting of the tube is to occur then this film must be locally disrupted. There are three mechanisms that allow the disruption of the protective deposits. The most well known, although now the least common, is the presence of carbon films on the bore. Stagnation and flux residues are the most common initiation mechanisms that have led to Type 1 pitting failures in the last 10 years. Carbon Films Copper tubes are made from the large billets of copper that are gradually worked and drawn down to the required size. As the tubes are drawn they are heat treated to produce the correct mechanical properties. The organic oils and greases used to lubricate the tubes during the drawing processes are broken down during the heat treatment and gradually coat the tube with a film of carbon. If the carbon is left in the bore of the tube then it disrupts the formation of the protective scale and allows the initiation of pits in the wall. The presence of deleterious films, such as carbon, has been prohibited by the British Standards in copper tubes since 1969 . All copper tubes for water service are treated, usually by grit blasting or acid pickling, to remove any films produced during manufacture with the result that Type 1 pitting initiated by carbon films is now very rare. Stagnation If water is left to stand in a tube for an extended period, the chemical characteristics of the water change as the mixed scale and corrosion products are deposited. In addition any loose scale that is not well adhered to the wall will not be flushed away and air dissolved in the water will form bubbles, producing air pockets. These processes can lead to a number of problems mainly on horizontal tube runs. Particles of scale that do not adhere to the walls and are not washed away tend to fall into the bottom of the tube producing a coarse porous deposit. Air pockets that develop in horizontal runs disrupt the formation of protective scales in two areas. The water lines at the sides and the air space at the top of the tube. In each of the areas that the scale has been disrupted there is the possibility of the initiation of Type 1 pitting. Once pitting has initiated then even after the tube has been put back into service, the pit will continue to develop until the wall has perforated. This form of attack is often associated with the commissioning of a system. Once a system has been commissioned it should be either put immediately into service or drained down and dried by flushing with compressed air otherwise pitting may initiate. If either of these options is not possible then the system should be flushed though regularly until it is put into use. Flux In plumbing systems fluxes are used to keep the mating surfaces clean during soldering operations. The fluxes often consist of corrosive chemicals such as ammonium chloride and zinc chloride in a binder such as petroleum jelly. If too much flux is applied to the joint then the excess will melt and run down the bore of a vertical tube or pool in the bottom of a horizontal tube. Where the bore of the tube is covered in a layer of flux it may be locally protected from corrosion but at the edges of the flux pits often initiate. If the tube is put into service in a water that supports Type 1 pitting then these pits will develop and eventually perforate the sides of the tube. Recommendations In most cases Type 1 pitting can be avoided by good working practices. Always use tubes that have been manufactured to BS EN 1057. Tubes greater than 10 mm in diameter made to this standard will always be marked the number of the standard, the nominal size, wall thickness and temper of the tube, the manufacturer identification mark and the date of production at least every 600 mm. Tubes less than 10 mm in diameter will be similarly marked at each end. Once a system has been commissioned it should be either put immediately into service or drained down and dried. If either of these options is not possible then the system should be flushed though regularly until it is put into use. It should not be left to stand for more than a week. At present stagnation is the most common cause of Type 1 pitting. Flux should be used sparingly. A small quantity should be painted over the areas to be joined and any excess removed after the joint has been made. Some fluxes are marked as water-soluble but under some circumstances they are not removed before pitting has initiated. References ^ Volume 13: Corrosion, Ninth Edition, Metals Handbook, ASM International, 1987. ^ V F Lucey, British Non-Ferrous Metals Research Association, Research Report Number A1692, 1968 ^ BS2871, Specification for Copper and Copper Alloy Tubes, Part 1. Copper tubes for water gas and sanitation ^ BS EN 1057: 1996, Copper and Copper Alloys Seamless, round copper tubes for water and gas in sanitary and heating applications External links Wikimedia Commons has media related to: Corrosion NACE International -Professional society for corrosion engineers ( NACE ) Copper Pipe Corrosion Theory and informations on Corrosion of Copper Pipe Categories: Corrosion | Pitting | Copper | Water

Home inspection in Downers Grove, Illinois answers questions about plumbing systems

Last month on a home inspection in Downers Grove, Illinois I was faced with a clients question about his “dream” home’s plumbing system.  This could be a potential costly issue depending on the age of the system and if any upgrades were made. There are basically 3 different systems in a home. The first is the water supply; which gives you your water ( hot and cold). The second system is tied to the third. This system is called waste and venting, which works together but could still operate without the venting but not advised.
There were 2 issues that needed immediate attention at this home inspection in Downers Grove.  Both items were what we call “defective”.  That doesn’t always mean that the repairs will be expensive. In this case,  the repairs would be some what costly due to the severity of the repairs needed.
The 1st item that we found at this home inspection in Downers Grove was the water piping.  The water piping was 87 years old and made of galvanize piping.  Generally galvanize pipe has a life span of 50 years. This homes piping system had lasted longer than the average galvanize system.  The “tell tales” of galvanize piping issues is generally seen at the fitting connections.  There would be pitting and rusting. The more severe the rusting , pitting and possible leaking the more severe the damage to the piping. Galvanize pipe corrodes from the inside out.  In this case, leaks were seen in the pipe walls.  My recommendation was to upgrade  the water piping system to copper.
The 2nd issue found at the home inspection in Downers Grove was a missing condensate drip leg used in the gas supply for the water heater.  This is not a costly repair but a nessecary one to prevent the corrsion of the water heater tank. There is moisture in gas and it needs somewhere to go or it will burn at the burner under the tank and cause the tank to corrode.  By adding a drip leg this will eliminate this concern.

Special features of kitchen faucets

Types of handle

Some faucets have only one handle, either fixed to the spout or standing apart from it. With these faucets you can quickly and easily control the flow of water and its temperature with one hand. This is especially useful when your hands are full or dirty.

Single handle kitchen faucet

Other kitchen faucets have two handles: one for cold water and the other for hot. The existence of two handles and two flows of water enables you to adjust the water temperature more precisely. More designs are available for two-handled faucets, as well.

Two handle kitchen faucet

If the handles have the shape of a lever or cross, you will be able to grasp and turn them more easily; levers are especially suitable for people with various physical disabilities.

Types of spout

The spouts of the kitchen faucets may be long, curved, straight, short, etc. Look for a faucet where the spout directs the water to the center of the basin of your sink.
If you will be washing large pots or pans, choose a faucet with a big spout that you can turn aside, with a high arch; for example, one about 14 inches (36 cm) long. Then it will be easy to put your large kitchen utensils in the sink and remove them after washing. Again choose a faucet with a big spout if your sink is big or you have several basins. Then the spout will cover as much of the sink as possible.

Pot filler

There is also one special spout – also known as a pot filler. You install it on the wall near the range to fill large pots with water when you cook. This saves you from having to carry these heavy utensils from the sink to the range. For this spout you will usually need a separate water pipe, supplying cold water.

Kitchen faucets operation

The quality of faucets depends on the materials and their mode of operation. To control the flow of water, they use such parts as…

• rubber washers
• ball valves
• ceramic cartridges
• ceramic disks…

Rubber washers wear out comparatively quickly, predisposing your faucet to leak. Ceramic disks or cartridges are far stronger and long-lasting. Faucets with such parts are more expensive, but they require little maintenance.

Kitchen faucets materials

Chrome and brass are materials of sufficiently good quality and are among the most frequently used materials for kitchen faucets. These are also faucets that require little maintenance.
Other materials may be used for the finishes on faucets, over a base of brass. For example, nickel, stainless steel, copper, zinc, bronze, silver, gold, etc. These materials can have a polished or matte finish, and may be used in combination with porcelain, glass or wood.
Keep in mind that there are some faucets you can buy in separate parts. Thus, you will be able to combine different materials, colors and shapes, to create your own design.

Kitchen faucets installation

You can install your faucet in the kitchen in three ways…

• through the sink
• through the countertop
• through the wall

The manufacturers usually supply detailed instructions on how to install the faucet. Another option is to use the services of a