HDPE pipe is easily and dependably joined using the standardized butt-fusion procedure. In this process matching ends of the pipes to be joined are aligned and heated with standard tools until the surfaces have become molten. When engaged under moderate pressure, the melt faces flow together forming a monolithic, homogeneous joint that, as the material cools, yields joints that are as strong as or stronger than the pipe itself.

There are several other well established heat fusion procedures used to join HDPE pipe such as electro fusion, which is exceptionally well suited for the assembly of pipe to fittings, or for making tie-ins or repairs, and saddle fusion which is used for the attachment of service fittings to HDPE mains. Apart from the heat fusion process of joining HDPE pipe, it can also be joined successfully with a variety of mechanical style fittings.