In general, a pp fitting should be the same material as the pipe to which you are fitting it. For example, use a PVC fitting with a PVC pipe. (There are exceptions where materials conforming to certain codes/standards can be used in pipes of another material.) Material options include: Copper Used with hot- and cold-water applications. Commonly used in residential water supply lines and as a refrigerant line in HVAC. Comes in soft form (usually for refrigerant lines) and rigid form for water pipelines. Copper pipes are usually joined using a flare connection, compression connection and sweat or solder connection. PVC (polyvinyl chloride) The most common type of plastic, it’s rigid and comes in a variety of pressure ratings. For cold water applications only. Standard uses include cold water supply and drainage. PVC fittings are joined by a thread or solvent weld (glue) connections. CPVC (chlorinated polyvinyl chloride) Similar to PVC but suitable at higher temperatures and more ductile. Primarily used for residential hot- and cold-water applications. Often replaces a copper pipe in indoor applications. CPVC fittings are joined by a thread or solvent weld (glue) connections. PEX For residential hot- and cold-water applications and as hydronic heating. Competitively priced and are easy to use. PEX is joined with plastic grip or metal crimp and clamp fittings. Good to know! Make sure you select a material rated for the type of plumbing job you are doing. For example, some pipes are approved for pressurized air or gas, others potable or non-potable water. Always check local code requirements to make sure the materials you select meet current standards.
