So many types of plumbing pipes are available that it is sometimes hard to determine which pipe to use for the job. There are different thicknesses and diameters of both metal and plastic pipe. Some plumbing pipes are manufactured for indoor use, while other pipes are required for outdoor use. Before buying any plumbing pipe, determine the use of the pipe.
Metal Plumbing Pipe
The most common metal plumbing pipe is copper. Copper plumbing, more expensive than plastic pipe, resists corrosion. Three sizes of copper pipe are available for plumbing purposes. Type M and type L are used for interior plumbing jobs. Type K has a much thicker wall and is used underground. The fact that copper splits when frozen is a drawback for use in areas exposed to frequent cold temperatures.
Stainless steel pipes are also made for indoor plumbing purposes. Very strong and even more resistant to corrosion than copper, stainless steel also costs more than copper piping.
Galvanized steel and cast iron have both been used in the past for drainage pipes. The life span for galvanized steel is approximately 40 years; however, its lack of resistance to rust and corrosion is a major disadvantage. The downside to using cast iron is its weight, but if you need to replace some of your cast iron piping, plastic plumbing pipe bonds well with it.
Many homeowners are finding cheaper alternatives to metal plumbing pipe.
Rigid Plastic Pipe
One of the first rigid plastic plumbing pipes used for ventilation and drainage was ABS (acrylonitrite-butadiene-styrene). Many regional plumbing codes have banned the use of ABS, but some manufactured homes may still have this plastic pipe in use.
PVC (polyvinyl chloride) pipe is another rigid plastic pipe used for cold water feeds in homes. Using PVC for hot water plumbing causes the pipe to warp and weaken. PVC is white, while CPVC (chlorine-polyvinyl-chloride) is a cream color or beige. CPVC can withstand heat and makes a good substitute for copper when running a hot water line.
Flexible Plastic Pipe
Cross-linked polyethylene, or PEX pipe, is a durable, flexible pipe. It is highly resistant to heat and comes in red, blue or white for quick identification. PEX pipe joints are formed with special couplings and fittings to ensure a leak-proof plumbing job. PEX plumbing is used in residential homes for water lines and also under floors for radiant heating systems. Another flexible pipe available for plumbing is HDPE (high-density polyethylene). Used for years as a covering for electrical wires, plumbers find HDPE very long lasting and noncorrosive. The high temperatures and pressures HDPE withstands makes this pipe good for most plumbing jobs, including water lines, gas lines and drainage lines.