Polyethylene Gas Piping Materials

Definition

• The polyethylene used to create gas piping is known as high density polyethylene (HDPE). The high density part is important, because the natural gas must be channeled through an incredibly safe system that prevents the possibility of fire hazards caused by leaks. HDPE is one of the few materials (along with certain types of copper piping) qualified to maintain natural gas and similar materials. It's available in sizes that match 1/2-inch and 3/4-inch pipes made from other materials.

Benefits

• Polyethylene is a plastic material, and has much greater flexibility than other types of gas lines. You can install it in older houses more quickly and route it more easily than other materials allow. It's also corrosion- and wear-resistant, making it ideal for underground applications as well. Its plastic nature also keeps polyethylene lightweight and easy to transport for major projects.

Problems

• HDPE gas lines are used in most (around 90 percent) of North American residential natural gas construction. But they're not designed for every gas application. Sometimes HDPE cannot be used because metal gas lines conform more accurately to certain projects that already use metal pipes, or HDPE does not come in the available sizes for proper installation.

Considerations

• HDPE piping must be installed and connected properly to work. Local building codes tend to require certification and training for HDPE in addition to certification required for dealing with natural gas. HDPE can be fitted with either heat-fused or mechanical fittings. With heat fusion there is a danger of melting and weakened the pipe, while mechanical fusion allows for leaks and misalignment, so both methods require training and careful application.