Sealing Stainless Steel Pipe Threads

[rallenc]

I was installing a stainless steel line through my basement wall for a hose bib. Thought I would get fancy and use stainless steel threaded pipe through the wall and for an 18 inch rise to the faucet. Used stainless fittings also.

On each joint I used the yellow "teflon" tape. Finish up and every stainless joint has a drop-drop leak. I noticed that the threads both male and female were very sharp and in a number of cases the "teflon" tape didn't seem to want to "grab" but had a tendency to rotate with the fitting as it was being installed.

In hindsight I did some research and it was recommended that Loctite, I think 567, would be better than the "teflon" tape.

Any thoughts on joining stainless threaded pipe?

Thanks for your wisdom.

 

[bigredmf]

High quality white Teflon tape with pipe dope on top of it.

With larger npt sizes you may need to pipe dope the female fitting as well.

Red


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[rallenc]

Thanks for the quick reply. Pipe is 3/4".

 

[Ole Slewfoot]

Captain obvoius here, Tef tape likes to be wound in the tightening direction of threads or it gets peeled out of the way.

and there is always tighten it more.

cheap pipe has horrible thread machining, but it evens out if you crank it down and loosen it,you might have better luck the 2nd time.

 

[6PTsocket]

I was installing a stainless steel line through my basement wall for a hose bib. Thought I would get fancy and use stainless steel threaded pipe through the wall and for an 18 inch rise to the faucet. Used stainless fittings also.

On each joint I used the yellow "teflon" tape. Finish up and every stainless joint has a drop-drop leak. I noticed that the threads both male and female were very sharp and in a number of cases the "teflon" tape didn't seem to want to "grab" but had a tendency to rotate with the fitting as it was being installed.

In hindsight I did some research and it was recommended that Loctite, I think 567, would be better than the "teflon" tape.

Any thoughts on joining stainless threaded pipe?

Thanks for your wisdom.

When all else fails, Loctite seems to have a product for the job. 567 is indeed recommended for stainless pipe thread.
I would take them at their word. They also have great customet support. They willingly discuss your bonding problems and explain the differences between similar products they make. I have spoken to them a few times.

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[aslack99]

I thread a bunch of stainless, and we use teflon tape with never seize on top of it. Works every time.

 

[58Yeoman]

High quality white Teflon tape with pipe dope on top of it.

With larger npt sizes you may need to pipe dope the female fitting as well.

Red


Sent from my iPad using Tapatalk

This is what we did at work when we used SS pipe. Tape first, then the dope. Worked very well.

 

[RAYJAY]

either rector seal 5 or blue block

and thought yellow Teflon was only for ng gas fittings????

good read on sealing pipe.

http://allthumbsdiy.com/plumbing/when-to-use-ptfe-teflon-yellow-or-white-tapes-or-pipe-dope

 

[matt_i]

I've used mostly the Loctite PST 565 in industrial/factory settings. Its ok for oil, gasoline, water, air, natural gas, hydraulic, transmission fluid, glycol and methanol service. Basically need 1 sealant for every application most people could ever run across.

Teflon tape is good for either getting pushed back off the threads or getting little shards to clog up some key piece of instrumentation downstream. It will work but needs more skill to apply than the PST.

 

[rayra]

Pipe dope would do, not sure why you'd need to use both, if applied and assembled properly.

 

[bob15]

I prefer white teflon tape. It also sounds like you wrapped the tape backwards.

 

[Schurkey]

Loctite, I think 567, would be better than the "teflon" tape.

Yes.

Loctite seems to have a product for the job. 567 is indeed recommended for stainless pipe thread.

Also yes.

I've used mostly the Loctite PST 565

Yes.

I prefer white teflon tape. It also sounds like you wrapped the tape backwards.

I use tape...rarely. Very rarely. Yes, wrapped backwards it's useless.

Loctite/Permatex 592 is what I stock in my shop.

As I understand it, 565, 567, 592 is all similar. Each has an "active ingredient" that HARDENS in the absence of air (anaerobic) like Loctite thread locker. All of them are sealants and anti-gall thread treatment.

565 and 567 are low-strength. 592 is medium-strength.

565 is fast-setting (4-hours repositioning time), 567 is high-temperature, 592 is high-temperature, slow-setting (24-hour repositioning time.) The slow-set makes it perfect for sealing bolt threads into a water jacket (Head bolts, for example) that need to be retorqued hours after initial assembly.

Feel free to verify the above, but do it on the Loctite/Permatex website, don't trust Amazon's descriptions.

592 is available at most any auto-parts store, or Amazon.
https://www.amazon.com/dp/B000AAJTYS/?tag=atomicindus08-20

 

[rallenc]

Thanks for all the replys.

As to the tape, I made sure that it was wound in the proper direction. I've always used the tape for other projects with no problem; this is my first effort with stainless.

Thanks to Amazon I' ve got a small tube of the Loctite 567 that I will give a try.

Again thanks for the assistance.

 

[LS6 Tommy]

Thanks for all the replys.

As to the tape, I made sure that it was wound in the proper direction. I've always used the tape for other projects with no problem; this is my first effort with stainless.

Thanks to Amazon I' ve got a small tube of the Loctite 567 that I will give a try.

Again thanks for the assistance.

Threaded SS parts gall when assembled. That's why anti seize is required on SS nuts and bolts. It probably shredded the PTFE tape.

Tommy

 

[rallenc]

Threaded SS parts gall when assembled. That's why anti seize is required on SS nuts and bolts. It probably shredded the PTFE tape.

Tommy

You are accurate. On those joints where the tape did not slip, upon disassembly it was pretty much shredded.

Thanks!

 

[EOC_Jason]

I had a little (drain?) plug on my pressure washer that would drip-drip-drip when I used it... Annoyed the heck out of me...

I unscrewed it and it was pre-installed with some of that thicker thread locker you sometimes see pre-installed on bolts. I cleaned it off and used pipe dope. Let it set up overnight for good measure... Still had drip-drip-drip... Cleaned that off and tried teflon tape... Still drip-drip-drip...

The plug never seemed to fit that tight in its threads (at least to me)... So as a last resort I had some of the purple low-stregth loctite (forgot the #), used that and let it set up overnight... NO MORE DRIP!

I've never had something so stubborn before but persistence paid off...

I don't know why, but typically for gas I use pipe dope. For air / water I'll use teflon... I've never used both at the same time.

Color of teflon (white/yellow/pink) is just the thickness, except for green that indicates oil-free I believe...

With stainless you always need some sort anti-seize, I would never thread two pieces together dry... I've seen some stainless on stainless pipe parts where the threads galled and the only way to save the inner piece was to cut the outer piece all along the threads, carefully... The loctite 567 says it prevents galling, so that's good.

 

[boosted-delslow]

White teflon and never seize is all we use at work and have never had a problem with leaking.

 

[sberry]

I just use green stuff and screw them tight. I got it all but rarely use anything else.

 

[ez-duzit]

Very surprised that no one has mentioned the best pipe thread sealant: Leak Lock.

 

[Fastfish]

Stainless pipe is much more difficult to seal then other materials. Often I use teflon tape with rector seal. Leaklock above, works good too.

 

[73RR]

I have used a lot of ss pipe but I prefer to use brass fittings and pipe dope to avoid the galling issue that will happen with ss to ss. Brass fittings always seal up better than ss fittings. Like others, Never-Seez, pipe dope, or some other lubricant with the tape when tape is used.

 

[sberry]

I got tape, I hardly ever use it. I got a fresh can of green stuff the other day. I had one for 2 years. Its been too hard to use right for a year.

 

[cherrybomb]

Since s.s. is a whole different animal,it takes a lil different approach. The threads are very sharp,it threads tape very easy.It also galls easy.Nobody likes do overs,so I would read the Locktite/Permatex site and decide on a high temp,fast set or a high temp slo set.I also like to do a visual on my threads,some times you can catch small problems.

 

[tonyciambrone]

We use "Blue Monster" Teflon tape and Loctite 567, although I have looked into other liquid or gel sealants.

Someone suggested "there's always tightening it more". Not with stainless. Not with most things for that matter but you will almost guarantee leaks. As others have stated Stainless will gall or actually start to rip it's threads to pieces and there will be little slivers of stainless entering the mix. That's why a lot of people do tape and a sealant or anti-seize, so that something will lubricate the threads to keep them from catching and ripping out.

Working with stainless pipe requires patience and occasionally some cursing.

If you are never ever going to undo a particular joint, Tig Welding leaves no doubt.