Stripped Needle Valves...

Not sure if I screwed up beyond recovery so I'm hoping you guys can help out. I am plumbing my rig for propane using 1/2" black gas pipe. I also am using two stainless needle valves for control to the individual burners. I think I overcranked and stripped the MPT on both the needle valves though. Originally, I really had to crank it down to get everything to line up correctly, and it felt like it slipped, so I think it stripped. Now to get it snug, I have to screw the elbow onto the pipe until it can't go any further. Even with a bunch of teflon tape, and some of the pipe glue, it still leaks.... can I use some silicone maybe?? Or how about throwing a bead of solder in between the valve MPT and the elbow FPT... or am I just f'ed and should get new valves??

Thanks!

Craig

Also, I already bought new elbows yesterday and it's still doing it. Looking at the threads though everything looks ok, but then again I don't know what I'm looking for.

you should be able to screw them together by hand and make 3 1/2 revolutions without ANY tape or pipe dope. So if it was real hard at the start maybe it got crossed threaded.

The valve threads should look clean if you remove the tape and dope and look in it.

I would start with new stuff. Sorry

I got this stuff at HD today called QuickSteel... it was an epoxy for metal.. I just tried it out.. put it in the female threads, then made a nice seal between the female piece and the male... let it cure for an hour as directed. Turned on the gas, still leaks. Guess it's time to buy new valves unless anyone has any better ideas???

mrmcdowe said:

you should be able to screw them together by hand and make 3 1/2 revolutions without ANY tape or pipe dope. So if it was real hard at the start maybe it got crossed threaded.

The valve threads should look clean if you remove the tape and dope and look in it.

I would start with new stuff. Sorry

Click to expand...

It's pretty easy at the start, I can do it several revolutions by hand before applying any extra force.