I'm installing the shower valve. Is it better to use a threaded slip fitting, or just a standard non-slip type? My worry is if I don't tighten the non-slip type enough, it will leak and I won't be able to tight anymore without undoing all the plumbing.

We're going to hafta get together on terms. To me a threaded slip fitting is a adapter with male or female threads on one end and the other is a open end that slips onto a copper pipe where it it will be soldered. I think you may be referring to a compression fitting. I have never advised,( and some local codes forbid) installing compression fittings inside the wall line. We use 1/2" MIP to slip copper adapters. These will screw into the shower valve inlets and solder on to the coppere supplies. Good luck, Tom

We're gonna hafta get together on terms. To me a threaded slip fitting is a adapter with male or female threads on one end and the other is a open end that slips onto a copper pipe where it it will be soldered. I think you may be referring to a compression fitting. I have never advised,( and some local codes forbid) installing compression fittings inside the wall line. We use 1/2" MIP to slip copper adapters. These will screw into the shower valve inlets and solder on to the coppere supplies. Good luck, Tom


I'm using CPVC if that matters. The adapters I need will be threaded on one end, and then solvent weld-able to CPVC on the other. The two types I'm referring to are slip, which allow for tightening of the threaded side, after solvent welding. And the other type is non-slip, where the threads are fixed to the solvent weld end.

Sorry if this doesn't make sense. For either adapter, they have the same connections at the end.

The two types I'm referring to are slip, which allow for tightening of the threaded side, after solvent welding. And the other type is non-slip, where the threads are fixed to the solvent weld end. Your slip fitting sounds a lot like a compression fitting to me. For CPVC we thread the adapter into the shower valve and glue the raiser to it. So I guess you would use the non-slip type. Good luck, Tom

How do you ensure that you've tightened the adapter enough? I'm worried that once I've tightened that, then glued, I won't be able to tighten since it will rotate the riser.

Any plumber knows when to stop cranking down on threads. Wrap a few turns of Teflon tape around the threads and crank them down until you can't tighten any more. I'd trust the threads to hold pressure over time a lot more then I would a compression joint. Remember, this is pressure we're speaking of. For pressure I prefer a solid connection. For drainage I use both a solid and compression fitting. Regards, Tom