what is the best way to join a brass fitting to pvc and pressure tests to 50 psi?

Question

using slic tite teflon paste getting leaks through the threads

Answer 1

Try putting some teflon tape on the threads and then use pipe dope over that. Perhaps you could intall a washer into the female threaded fitting before screwing them together.

Answer 2

I would use a PVC female adapter solvent welded to the PVC pipe and a male adapter on the brass fitting. Teflon tape is good, but shouldn't be necessary.

Need to remember tapered pipe threads really aren't supposed to be reusable. The threads are distorted when the joint is made so if you take it apart it may not reseal.

If you want a fitting you can take apart and reconnnect I'd use "Boss O-ring" fitting as used for hydraulics. Those thread are straight and the o-ring makes the seal.

Answer 3

Clean the threads, now rap the male threads with Teflon tape in a clockwise direction, at least two layers. Now make up the joint. PVC threads are same as regular pipe threads, they are tapered. Check your brass fitting threads, making sure they are tapered also. If they are straight threads, you will never get this joint to seal.

Answer 4

Use teflon tape .
Paste is used only as a lubricant to reduce friction allowing a tighter fit, something you dont want to do with a plastic pipe.
P.S.
make sure the pipe you are using is rated to with stand 50psi or better.
or you may be using the tape to close wounds while waiting for the ambulance

Answer 5

Try using 3M Type 101 Sealant or Type 5200 Sealant between the threads. 101 stays flexible and 5200 is almost unremoveable.