Whether you are a professional or just curious about the system that brings water to and from your home, the plumbing pipe system is the veins that carry hot and cold water to the home, as well as drains the waste away. But there is no one plumbing pipe type that fits all. Each type of pipe has its own pro’s and con’s, which is why they are utilized in different areas. The two basic categories are supply and drainage, or for our purposes, metal and plastic.
Metal Plumbing Pipe Types
These are the most common of the metal plumbing pipe types. For years, copper was the standard due to its corrosion resistance, inability to rust, and tolerance for high temperatures for the purpose of supplying heated water. Copper pipes also work well for carrying water around corners without
substantial wear. However, copper is used less in drain lines due to its higher cost, but older homes can have copper drainage, waste, and vent pipes (DWV). The pipes are easy to identify due to their copper color. The average life span for copper plumbing pipes is 50 plus years.
Cast Iron Pipes
These pipes are primarily used for drainage. Their heavy weight gives them ample life but also makes them difficult to replace when they do wear down. The good news is the average life span of cast iron drain pipes can be 75 to 100 years.
Galvanized Steel Pipes
These pipes experienced a brief usage mostly in the sixties in an effort to find cheaper plumbing material. However, they were also susceptible to hot temperatures, wear in joints, and quickly replaced by other types. These pipes are metallic, may have a shine, and threaded fittings. Their average life span is 20 to 50 years.
Stainless Steel Pipes
They are used even less than galvanized steel due to their high cost. However, because they are resistant to the corrosion found in salt water, they are used in marine applications or anywhere salt water can be introduced to the piping.
Chromed Brass Pipes
If the drain underneath your sink(s) has a shiny chrome finish, it is usually a chromed brass pipe. Due to its aesthetic appeal, chromed brass is used whenever plumbing pipes are exposed as in underneath a sink, P trap, or other drain traps.
Black Iron Plumbing Pipe Types
These pipes are not used in any type of plumbing. Instead they are used to carry gas. Some homeowners mistake their dark pipes as black iron due to its similar appearance to other types of plumbing pipes.
Iron and Lead Pipes
Only found in older homes, the use of lead pipes in homes was banned in 1996 by the Clean Water Act. It was used commonly to connect houses to municipal water lines. Homeowners who suspect or know that lead pipes are carrying water into the home can request the city/county replace them. Iron pipes were once used as both supply and drain lines yet were so susceptible to rust and corrosion, they were quickly replaced by other materials.
Plastic Plumbing Pipe Types
Plastic is replacing metal as the most commonly used material for household pipes due to its low cost, corrosion and rust resistance, and durability.
Acrylonitrite-butadiene-styrene (ABS) Pipes
One of the first plastics to be used in plumbing, ABS exhibited good rigidity and resistance to high temperatures. However, as new plastics became available, ABS was quickly replaced and some plumbing codes forbid installing them. They can still be found as drain lines and usually have a black plastic appearance.
Plastic Polybutylene (PB)
Also known as Quest in gray or beige, this is also one of the earlier attempts to use plastic as plumbing pipe. Used from the late seventies to early nineties, the pipe is inexpensive and easy to install but more prone to leaks than the copper pipes it was supposed to replace. They are gray or white in appearance – white for drainage.
Polyvinyl Chloride (PVC)
PVC is one of the most common plastics found in plumbing pipes. It is rigid and resistant to water or chemical damage. However, the pipe can be damaged by hot water and has a high failure rate at joints subjected to high pressure. This is why it is mostly used as a cold water supply line or in drainage. When used correctly, PVC can last as long the residence its installed in.
Chlorinated Polyvinyl Chloride (CPVC)
A build on the above plastic, this pipe has been given extra chlorination to help it withstand the high pressure and high temperatures previously unavailable with normal PVC. CPVC can carry hot or cold water into the home but should not be used in drain lines due to its tendency to split in freezing temperatures. This pipe is usually white, beige, or slightly yellow.
Cross-linked Polyethylene (PEX)
PEX lines are a flexible, inexpensive plastic made of cross-linked high density polyethylene polymer. It can withstand temperatures from 32 degrees to 200 degrees Fahrenheit, 0 degrees to 93 degrees Celsius. It flexibility and rigidity makes it easy to install while reducing the possibility of leaks. PEX pipes usually came in white, but are now colored blue and red to signify hot and cold water supply lines.
This black pipe is primarily for outdoor use, as in for garden irrigation and drip systems due to its resistance to cold temperatures. Poly pipe should not be used in the home.
Other Important Facts About Plumbing Pipe Types
- Copper pipes are becoming more valuable, and there has been an uptake on plumbers salvaging them before a home is torn down.
- If you suspect lead pipes in your home, look for a dull gray appearance on the pipe and the ability to easily scratch the surface with a knife or key.
- There are home kits available to test your water for lead. An acceptable level of lead in water is less than 15 parts per billion.
- One of the best ways to keep your plumbing pipe systems lasting longer than the average is to eliminate hard water. If testing your water confirms hard water, or water with a high mineral content, a water softener can help eliminate it.
- In the United States, hard water is most often found in the Southwest and parts of the Northeast. Signs of hard water include the white buildup on shower heads and faucets.
- By law, every municipality must file an annual water quality report with the Environmental Protection Agency, which is public information. The report can include items such as hard water, minerals, lead content, etc.
- Another good way to extend the life of your plumbing pipes is to reduce the pressure on shower heads, hoses, etc. The more stress put on your plumbing by high pressure, the more likely it is to fail sooner.