If you need to connect a high density polyethylene (HDPE) pipe to a polyvinyl chloride (PVC) pipe, you need to use a transition fitting to ensure a leak-proof seal between the two pieces of plastic pipe. Different types of plastic expand and contract at different rates. A transition fitting allows each pipe to expand and contract at its own rate and keeps a seal between the two.
Things You'll Need
Hacksaw or miter saw
Cut the end of the HDPE and the PVC pipe at 90-degree angles with a hacksaw or miter saw to ensure a flat face on the end of each pipe.
Debur the cut ends of the pipe with a razor blade or a deburring tool. A bur is the material left on the pipe after you cut it with a saw. This material could break off and get caught in a pump or drain at some point so it is important to remove it.
Slide the transition fitting onto the HDPE pipe.
Slide the HDPE pipe over the end of the PVC pipe. It is important that the inside diameter (ID) of the HDPE pipe be as close to the outside diameter (OD) of the PVC pipe as possible. This creates a butt fusion joint between the two pipes.
Slide the transition fitting over the HDPE and PVC pipe and center it between the two pieces. Tighten each end of the fitting with a pipe wrench.