About: Plumbing Pipe
Plumbing Pipe Types
The average building owner doesn't think much about his or her plumbing lines when they're working properly. When something goes wrong or it's time to buy materials for a remodeling project, all that changes.
Figuring out the right options can be a challenge because there are multiple types of pipe materials and each of them is used for a different purpose. Whether homeowners intend on completing their own plumbing projects or they just want to better understand their plumbers' advice, they can find out everything they need to know about these materials below.
PEX is short for polyethylene cross-linked pipe. It is a type of plastic tubing that's much better than a galvanized pipe for water supply. PEX pipe is:
These unique benefits help to explain why older homes' galvanized pipe is quickly being replaced with PEX and other more modern alternatives. They allow plumbers and home handymen to use PEX pipe in a variety of freshwater transfer applications.
PEX pipe can be attached to water distribution manifolds to bring fresh water to sinks, showers, and water-using appliances. Since each pipe has an independent shut-off valve, plumbers or home handymen can shut the water off to one fixture in order to make repairs without having to shut off the main water line.
Most PEX pipe is also color-coded to make it easier to keep home plumbing systems organized. Plumbers traditionally use red PEX pipe for hot water lines, blue for transporting cold water, and white pipe for multi-purpose lines.
PVC, short for polyvinyl chloride, is most commonly found in sewage systems. It's only suitable for low-pressure, low-temperature applications such as drain traps, vent pipes, and repairs or replacements of cast iron drain pipes. PVC pipes come in multiple diameters and schedules, so it's important to choose the right one.
For a while, PVC was considered the de facto home standard for wastewater. It is inexpensive and easier to work with than most alternatives since it can be cut easily with a hacksaw. However, it is also prone to leaking at connections, and it is prone to both heat and sun damage.
Copper pipes have been in use for far longer than either PVC or PEX pipes. They're just as common in older homes as they are in new construction. This material can be used for both water lines and gas pipeline.
Most water supply lines feature type M rigid copper. Types K and L are also common in other plumbing and gas lines. Flexible copper is used primarily for short water supply runs such as tubing for refrigerators or dishwashers.
Copper's popularity can largely be attributed to its versatility and corrosion resistance. It can develop pinholes or rupture due to freezing, though. Installing copper pipes is also a job best left to professionals since it requires the use of a propane torch. Homeowners should only attempt to install or repair copper pipes themselves if they have sufficient experience with soldering to ensure a proper seal.
These black pipes look a lot like PVC in a different color. They come in the same sizes and schedules and are used for some of the same purposes. The difference is that they're made from acrylonitrile butadiene styrene (ABS), which is slightly more impact-resistant than PVC.
ABS used to be common in new construction and was used as both drain and vent pipes. These days, that's rarely the case. While the material is stronger than PVC, it is equally prone to warping at high temperatures or under direct sunlight and its use is often precluded by local building codes.
Chromed Brass Fixtures
Chromed brass is used primarily in exposed drains, traps, and other plumbing fixtures where aesthetics are important. It is more expensive than PVC but can be installed by homeowners if they have the right tools and experience. Chromed brass can be cut using nothing more than a hacksaw and parts can be joined together using simple slip fittings.
Galvanized Iron Pipes
Before the advent of man-made materials like PVC and PEX piping, galvanized iron was one of the most common materials used in plumbing supply lines. The reason it's no longer used in new construction is that it is prone to corrosion and rust.
Galvanized iron must be cut and joined off-site by a trained professional. Most homeowners who plan to replace galvanized iron pipes do so by installing copper or PEX alternatives. These days, the only place galvanized iron pipes can be found is in older homes.
Black Iron Pipes
While galvanized iron has fallen largely out of favor, black iron is still relatively common. It looks a lot like galvanized iron but is used primarily for gas lines. Like galvanized iron pipes, black iron pipes must be cut and fitted by a professional. It's common to find them in gas supply lines for water heaters, boilers, furnaces, and other home heating appliances.
Cast Iron Pipes
It's very rare to see cast iron used in new construction, but older homes often have cast iron wastewater pipes. This strong, long-lasting material is very difficult to work with. Cutting and fitting it requires specialized tools such as cast-iron pipe cutters, lead and oakum pipe joints, and either hubbed fittings or hubless couplings with pressure bands.
Homeowners with older properties may eventually need to repair or replace cast iron pipes. The best materials for replacing outdated cast iron wastewater lines are PVC and ABS, though the latter may not be allowed by building codes.
Choose the Right Materials for the Job
These days, home handymen and plumbers alike tend to prefer PEX pipe for freshwater supply and either PVC or ABS for wastewater pipes. Black iron or copper are equally popular for gas lines. The best way for contractors, plumbers, and home handymen to choose the right material is always to contact a plumbing supplier or pipe manufacturer directly.