Polybutylene to copper

[RRFisher]

I have a contractor remodeling a bathroom. My house is plumbed with 5/8" Vanguard Polybutylene (PB) pipe. He is using a Qest connector to connect the PB to copper to plumb the shower. His connector is plastic on both ends, a plastic ferrule, and a Qest metal ring with the ferrule. The shower is to be plumbed with 1/2" copper. I have looked through the Qest fittings but nothing jumps out as a better adapter (which I believe there must be.) I have a brass/plastic compression connector for 5/8" PB to 3/8" copper. If I can find a 5/8" PB to 1/2" copper would that be a better solution ? I have asked him to cut the PB above the ceiling of the garage, very close to the shower with the connectors accessible in the garage. If a connector fails, I have access and I also have opportunity to retrofit.

 

[Clayton]

PB sweat adapter

As for compression fittings to adapt from the PB to copper, In my opinion none of them are good. The Qest qicktite fittings and Flair-it fittings are probably going to be the most common. You could also use a standard copper compression coupling but replace the brass ferrule on the PB side with a plastic one and use a stainless steel insert stiffener in the end of the PB tubing. Personally I wouldn't use any of them in my own house. I would want to go ahead and replace all the PB in the house, but understandably that is probably not in the budget.

Instead of using compression fittings, ask your plumber if he has pex crimp tools and ask him to use the original sweat to PB adapters. A few supply houses and even some internet companies still have these fittings in stock. I've got a decent supply of most of the fittings except the swivel adapters.

Good luck...