Can't beat Leaks at Couplings

Hi,

DIY'r here. I have a leak and tried 2 setups as indicated below, arrows show what I did in-line. I have this problem below a sink and shower faucet. All new hardware.

CPVC to 1/2" CPVC male adapter >>Leak>> 1/2 - 3/8 Water Supply Valve>> 3/8 - 1/2 Flex Host >> Faucet

CPVC to 1/2" CPVC male adapter >>Leak>> 1/2 - 3/8 Water Supply Valve>> 3/8 - 1/2 Flex Host >> Faucet

Used Tephon tape at every coupling " >> ". In both cases the leak occurred between the adapter & the water supply 1/2 side of the water supply valve. I tried 2 and 3 layers of Teflon tape, light tightening, then very strong tightening.


What's going on? After laying 20 feet of CPVC, and replacing drainage system for bathroom, I'd be embarrassed to call a plumber because I can't get what I thought would be straightforward fittings not to leak.


- David

Try these transition fittings...
Plastic threads are oh so lame...

Hey Redwood,

I really appreciate your time. Hears what I've done... and what you suggest... just to be clear.

Not sure why copper to (what ever the metal is that the valve is... steel with crome?) wouldn't work.

Thanks,

David

The top way in you picture is a guaranteed leak.

The second and third one is slightly better but has an extra connection that could be a problem.

The method I showed using the male transition fitting should work well I would wrap the male threads with teflon tape then use a teflon pipe dope such as magaloc over it. Kinda like a belt and suspenders approach.

valves

Most plumbers would have used compression valves rather than screwed ones and avoided the problem entirely.

If you have done this a few times the stop may have expanded and that may be causing the problem... not enough teflon tape...a fine crack in the stop...bad threads...not tight enough...try getting a new stop...personaly I use 4-5 wraps of teflon...

Thanks

Thanks again to all. going to try these responses in order of least cost, and hope to be rid of the leaks. Next I'll call a plumber.