A plastic plumbing system pipe isn’t easily corroded by exposure to water and common household chemicals. Plastic formulas can be adjusted to allow them to stand up to the demands of various residential plumbing needs, including water supply and drainage.Unlike metal, plastic doesn’t conduct heat well so it’s better able to maintain the temperature of the water it carries. While copper pipes require insulation to prevent sweating and dripping, PVC pipes stay dry even with no insulation. That’s especially helpful with condensate drains for air conditioners, boilers and other appliances.Connecting dissimilar metals, such as copper and iron, can cause corrosion. Plastic pipes can be connected with each other or with metal pipes without the risk of damaging chemical reactions.Because plastic pipes are light and easy to handle, plumbing jobs done with these pipes nearly always cost less than those that involve metal pipes.Some plumbers find plastic drainpipes are less likely to clog than metal ones and are easier to unclog when they do.
Although plastic pipes don’t transfer heat well, they do expand and contract depending on the temperature of the surrounding air and the fluid inside them. Ultimately, this shouldn’t cause any problems because a skilled plumber will account for this tendency when choosing the pipes.Plastic melts or burns at lower temperatures than most metal, and it can emit toxic fumes even before melting. That presents an added danger in the event of a house fire. Because of this, building codes place more safety restrictions on plastic pipes than on metal ones.One of the most popular pipe plastics used today, PEX is commonly installed in place of copper pipes or chosen as an alternative to other types of plastic. It’s often installed to deliver both hot and cold water, particularly drinking water. It’s also a popular choice for appliances such as boilers. This material is known for its flexibility, low cost, ease of fitting and ability to maintain water pressure. PEX pipe is available in red, blue and white. While red is typically used for hot water and blue for cold, there’s no difference in the material.Another material popular for the modern plumbing system pipe.
PVC is a white or grey pipe used for high-pressure water, most commonly the main supply line into the house. It isn’t as flexible as PEX, making it less appropriate for smaller interior spaces. Its tendency to warp at high temperatures means it shouldn’t be used to carry water hotter than 140 degrees. That makes it inapplicable for kitchen drains, where hot water from cooking or the dishwater could damage the pipe. Certain versions of PVC, in particular pipes rated DWV (drainage, waste and vent), may leach chemicals and shouldn’t be used for drinking water. CPVC is PVC that’s been treated with chlorine, a process known as chlorination.
CPVC is more easily shaped and more flexible than PVC, and it can stand up to higher pressures and temperatures. These properties make CPVC popular for industrial applications, but this pipe is also used to carry residential drinking water. On the downside, its flexibility means it requires more support than PVC pipes. Because it will crack if frozen, it shouldn’t be used underground.One of the toughest plumbing system pipe materials around, HDPE works well for nearly all plumbing uses. It’s durable, flexible and resists corrosion well. These pipes are available in long lengths, and any joints necessary are made using heat fusion, which is almost leak-proof. HDPE conserves water pressure because it creates minimal “drag” or friction that reduces water pressure.