plastic pipe

Since a home's metal plumbing was often used as the ground for its electrical system, if you install plastic pipe somewhere you must make sure that you haven't accidentally disconnected the ground. To reduce such errors, the National Electrical Code requires that in new construction, if the ground connection is made to a water pipe, it must be made within a few feet of the point where the pipe enters the building.

Types of plastic used for plumbing

Name of resin	Uses	inch- based	metric
polyvinyl chloride		PVC	PVC-U
chlorinated polyvinyl chloride		CPVC	PVC-C
acrylonitrile-butadiene-styrene		ABS
high density polyethylene		HDPE
cross-linked polyethylene		PEX
polybutylene	No longer used in residential plumbing.	PB
polyethylene (PE)
rubber-modified styrene (SR)
polypropylene (PP)
polyacetal