They grey pipe you are referring too is polybutylene, it was the subject of one of the largest class action lawsuits in Plumbing history and is no longer used. Transition to a different pipe depends on the method used for installation. This job may involve a considerable amount of repiping I recommend calling a licensed plumber. Check the polybutylene class action settlement to see if you qualify. The dates for most of the settlement relief is already past.
It stands for Chlorinated Poly Vinyl Chloride
Poly Propylene Random pipe
poly venal chloride
Termites can and do attack (eat) poly pipe used in pools. Before a homeowner uses poly pipe, it is suggested that they contact the poly pipe manufacturer since studies and the factory specs clearly establish it. I have seen termites repeatedly damage self installed poly pipe on an in ground pool. If poly pipe is used, it is absolutely mandatory that the surrounding soil be be treated for termites.
Should be a thick wall 3/4 poly pipe .
Coated Copper Pipe that is approved for underground only.
Chlorinated Poly (Vinyl Chloride) (CPVC) is a thermoplastic pipe. CPVC piping which is suitable for hot and cold water distribution has a 400 psi pressure rating at room temperature, and a 100 psi pressure rating at 180 F.PVC pipe cannot meet the high temperatures that CPVC pipe can. PVC corrosion resistant pressure pipe, IPS sizes 1/8" through 24", is ideal for use in applications with temperatures up to and including 140°F.
hardened poly vinyl chloride
The scientific name for PVC pipe is polyvinyl chloride.
It stands for Chlorinated Polyvinyl Chloride (CPVC). Typically used for somewhat corrosive media.
A male and female thread connection if metal pipe. If poly pipe a welded fusion connection.
It may be Poly Vinyl Chloride as in PVC pipe.