Comments on: plumbing question about polyethylene.

By: George’s Bush

George’s Bush — Tue, 30 Nov 1999 00:00:00 +0000

there are all types of fittings to convert one type to another. You want to find the kind that has a plastic ring and it it used with a pressure fitting.

By: myangel28379

myangel28379 — Tue, 30 Nov 1999 00:00:00 +0000

Go to a plumbing supply place, they have the fitting, it’s a two piece fitting, using compression on one end and glue on the other. You also want to use pvc not cpvc for anything running cold water, cpvc for hot water. Schedule 40 in the wall or anything covered, schedule 80 would be used for any showing pipes or outside pipes. Also use pipe insulation if you live in cold weather for hose silcock, if you need me to explain further contact me from my page. Make sure to use straps at least every eight feet. If you use well water make sure you have a diaphram, city water would need to add a water hammer.

By: GTB

GTB — Tue, 30 Nov 1999 00:00:00 +0000

You have talked about different things.

1. You cannot convert polyethylene (PE) in to chlorinated polyvinyl chloride (CPVC) in your environment. Polyethylene is a polymer made by polymerization of ethylene. Chlorinated polyvinyl chloride is made from polyvinyl chloride. Polyvinyl chloride is made by polymerization of vinyl chloride. End products of polyethylene and of chlorinated polyvinyl chloride have markedly different properties as they are markedly different in their chemical composition.

2. PEX is cross linked polyethylene. The cross linking of the linear polyethylene chains makes a markedly different product with markedly different properties than polyethylene - as they are markedly different in their chemical composition. This is why brass compression fittings fail to perform with PE but perform with PEX - they are markedly different materials.

3. Although you did not ask, you cannot convert Polyvinyl chloride (PVC) to CPVC. The process entails substantial chlorination of PVC forming CPVC and HCl. This chemically intense operation requires substantial processing equipment, technically proficient personnel, etc. It is performed on the PVC resin prior to converting the resin into end product. CPVC has properties that distinguish it markedly from PVC as well.

I know you don’t want to hear it, but if you want the performance of PEX or CPVC you need to physically remove and replace. Surely a lot of work but this is the only choice.