Sealing pipe threads?

[aangel]

Hey I have various 1/2" NPT parts in my rig. Some are 316SS, some 304SS, and with different manufacturers/quality. A few parts do not fittogether all that well. Also, I really want to line up all my valves, barbs, etc, and that seems impossible to do.

I'm thinking of using Loctite 2046 or RTV silicone to semi-permanently "glue" my parts together and seal them up.

Tips? The loctite stuff is anti-galling and rated food-safe. I'm also wondering if silicone glue could be used...though that seems like it would be a more permanent solution. Note: I've tried the whole "multiple rolls of plumber tape" thing. Even went as far as 10 turns of tape and STILL some won't seal nicely, and in any case my ball valves take so much torque to turn that I'm afraid standard use of the brewery will un-seal teflon tape.

 

[GHBWNY]

Seems like the Loctite would be the best bet being food-safe. It also has an anti-bacterial component to it. And it lubes as you tighten but comes apart easily after setting.

 

[aangel]

Halfway through testing the Loctite - applied it, threaded everything together and hoping for victory. Something to note: it's REALLY thin. One of my threaded fittings, in order to face the proper direction, had to be not very tight whatsoever...and it's still hella loose even with the Loctite after 18 hours application now. This stuff has basically nil adhesive power.

On the plus side, I did some more digging and found this master list of RTV Silicone adhesive/sealant/caulk products which meet NSF standard for food safety. I'm pretty sure I'll be making double sure of my seals by silicone caulking all my threaded fittings. Will first wait 3 days for the Loctite to dry, since I applied it rather liberally.

 

[raysmithtx]

I believe if you were to use Loctite Pipe Sealing CORD then you could adjust the fittings inline without having any leaks. Kind of expensive but it's supposed to do exactly what you are looking to do.

 

[Ozarks Mountain Brewery]

I just use Blue monster Teflon tape, its about 3 wraps in 1, lately Ive made major changes and like the idea I can take things apart

 

[FloppyKnockers]

My go to is pipe dope then tef tape. I used this when fitting fire suppression sprinklers. Never had a leaky joint.

 

[29Savoy]

Pink or yellow Teflon tape. The former is used in household plumbing so its safe. But you need a couple of wraps to ensure a good seal. The yellow tape is for gas fittings and is thicker so fewer wraps are needed. As noted earlier it allows easy disassembly.

 

[aangel]

Pink or yellow Teflon tape. The former is used in household plumbing so its safe. But you need a couple of wraps to ensure a good seal. The yellow tape is for gas fittings and is thicker so fewer wraps are needed. As noted earlier it allows easy disassembly.

As I said earlier, I've used upwards of 10 wraps trying to get these fittings to play nice. I have lousy parts of different steels (316/304) and different thicknesses from different manufacturers.

Also, tape creates a good seal IF you tighten the fitting fully. Some of my fittings need to be oriented in certain directions (see picture of my manifold as it dries). Honestly I should probably be using triclamp but can't afford it.

 

[2grit]

I'm a pipefitter by trade and this is how you will never get a leak. Buy some Loctite 567 thread sealer (not cheap but works best of anything I've ever used). It is food grade. http://henkelna.com/us/content_data/140389_LT5086_FoodBevTL_Brochure_LR.pdf

Apply 3-4 wraps of Teflon tape to the male threads. Apply Loctite 567 to the male and female threads. Be sure the Loctite is applied all the way around the fitting leaving no dry empty spots. You only need apply to the first 3 or 4 threads. Tighten the joint but not overtighten. You just don't need to overdo it with this stuff. It is really that good. Loctite gave a demonstration showing how good their product is. They actually hand tightened the joints and no leaks. I don't recommend this because it's not always an ideal situation. Their demonstration uses factory fittings. I use factory also but have to thread my own most of the time and sometimes the threading dies are a little dull. I still never get a leak with this stuff.

Loctite says you don't need Teflon tape. Trust me, with stainless steel, use it. I've threaded thousands of stainless joints and it will gall.

The nice thing with this stuff concerning the OP's header he is building is that he wants to orient the valves just so. With stainless, it is challenging to not gall the threads in the process of getting everything tight enough to not leak. Use the Loctite, tighten liberally and it doesn't leak.

I probably sound like a Loctite salesman. Trust me, I'm just a huge fan of the stuff.

Loctite 567 is the recommended sealant for stainless but works
on all metals. Hope this helps. Let me know if I haven't answered all questions

 

[b-boy]

I just use Blue monster Teflon tape, its about 3 wraps in 1, lately Ive made major changes and like the idea I can take things apart

I use this too. It works well and doesn't seem to shred like regular silicon tape.

 

[cowboy1]

I'm a pipefitter by trade and this is how you will never get a leak. Buy some Loctite 567 thread sealer (not cheap but works best of anything I've ever used). It is food grade. http://henkelna.com/us/content_data/140389_LT5086_FoodBevTL_Brochure_LR.pdf

Apply 3-4 wraps of Teflon tape to the male threads. Apply Loctite 567 to the male and female threads. Be sure the Loctite is applied all the way around the fitting leaving no dry empty spots. You only need apply to the first 3 or 4 threads. Tighten the joint but not overtighten. You just don't need to overdo it with this stuff. It is really that good. Loctite gave a demonstration showing how good their product is. They actually hand tightened the joints and no leaks. I don't recommend this because it's not always an ideal situation. Their demonstration uses factory fittings. I use factory also but have to thread my own most of the time and sometimes the threading dies are a little dull. I still never get a leak with this stuff.

Loctite says you don't need Teflon tape. Trust me, with stainless steel, use it. I've threaded thousands of stainless joints and it will gall.

The nice thing with this stuff concerning the OP's header he is building is that he wants to orient the valves just so. With stainless, it is challenging to not gall the threads in the process of getting everything tight enough to not leak. Use the Loctite, tighten liberally and it doesn't leak.

I probably sound like a Loctite salesman. Trust me, I'm just a huge fan of the stuff.

Loctite 567 is the recommended sealant for stainless but works
on all metals. Hope this helps. Let me know if I haven't answered all questions

Pipefitter here also, and agree 100% with 2grit. This will solve your problem. Only thing I could add is to chase all threads with a tap and die set for the pipe thread size you using.

 

[aangel]

Pipefitter here also, and agree 100% with 2grit. This will solve your problem. Only thing I could add is to chase all threads with a tap and die set for the pipe thread size you using.

If the loctite's applied to the teflon tape...aren't I screwed the second some force is applied to the fitting in the wrong direction? The teflon tape loses all its effect the second you unscrew the fitting even a little.

 

[2grit]

If the loctite's applied to the teflon tape...aren't I screwed the second some force is applied to the fitting in the wrong direction? The teflon tape loses all its effect the second you unscrew the fitting even a little.

Not at all. The Loctite contains Teflon itself and even if it didn't, the Teflon tape is still there doing it's job reducing metal on metal friction. Trust me, I have backed fittings off a lot and retightened and still get a seal. It works

 

[2grit]

Pipefitter here also, and agree 100% with 2grit. This will solve your problem. Only thing I could add is to chase all threads with a tap and die set for the pipe thread size you using.

Great advice on chasing threads. And to get a fellow pipefitter to agree with another is quite a feat!!!! Haha

 

[aangel]

Not at all. The Loctite contains Teflon itself and even if it didn't, the Teflon tape is still there doing it's job reducing metal on metal friction. Trust me, I have backed fittings off a lot and retightened and still get a seal. It works

I guess what I meant is less about the friction reduction and more about the "tightening/sealing" effect. I find that when I unscrew teflon taped fittings, they become a bit looser, and I have to rescrew them back on further than the 1st time. On these fittings of mine, even with 10 loops of teflon they're not sealing up nice and tight. By tight, I mean "doesn't budge when opening / closing the ball valves, which require quite a bit of torque"

At the heart of it, I have loose-fitting NPT fittings that I wish to orient in such a way that they're HELLA loose. I could tighten them to the point of galling but it wouldn't give me the full extra turn needed to bring the fittings back to the orientation I want.

So what can I use, with these very loose fittings, to put them together in my desired orientation, seal them against leakage, and more importantly, lock them to the point that hand tools and a bench vise are required to unscrew them?

 

[2grit]

I guess what I meant is less about the friction reduction and more about the "tightening/sealing" effect. On these fittings of mine, even with 10 loops of teflon they're not sealing up nice and tight. By tight, I mean "doesn't budge when opening / closing the ball valves, which require quite a bit of torque"

At the heart of it, I have loose-fitting NPT fittings that I wish to orient in such a way that they're HELLA loose. I could tighten them to the point of galling but it wouldn't give me the full extra turn needed to bring the fittings back to the orientation I want.

So what can I use, with these very loose fittings, to put them together in my desired orientation, seal them against leakage, and more importantly, lock them to the point that hand tools and a bench vise are required to unscrew them?

Glad you asked. I should note that there is one thing I have always hated about Loctite thread sealant, and that is having to unthread a joint after the sealant has set. It takes a lot of effort to unthread a joint after about 24 hours or more. This will work perfect for you. In the case of a joint as loose as you're describing, wrap Teflon more than 3 times. I don't know if I would wrap 10 times but 5 or 6 wraps should suffice. Dope the joint and it will be good. BTW, a joint as loose as you're describing sounds like used fittings or non factory fittings that were cut too deep.

It's worth noting that you don't have to wait for the sealant to set. it will be sealed from the get-go.

Also, Run a lot of hot water through the piping to make sure any residual pipe dope inside is washed away and doesn't taint your product with an off flavor. Rinse a few times until you're sure it is clear.

A few years ago I was given some Teflon tape that was supposedly meant just for stainless. It's described as "full density". It is quite a bit thicker than "normal" tape. I personally didn't like it. It seemed to push out of the joint. But I wasn't dealing with loose joints like you are describing. Point is, this thicker tape might work for you

 

[aangel]

Glad you asked. I should note that there is one thing I have always hated about Loctite thread sealant, and that is having to unthread a joint after the sealant has set. It takes a lot of effort to unthread a joint after about 24 hours or more. This will work perfect for you. In the case of a joint as loose as you're describing, wrap Teflon more than 3 times. I don't know if I would wrap 10 times but 5 or 6 wraps should suffice. Dope the joint and it will be good. BTW, a joint as loose as you're describing sounds like used fittings or non factory fittings that were cut too deep.

It's worth noting that you don't have to wait for the sealant to set. it will be sealed from the get-go.

Also, Run a lot of hot water through the piping to make sure any residual pipe dope inside is washed away and doesn't taint your product with an off flavor. Rinse a few times until you're sure it is clear.

A few years ago I was given some Teflon tape that was supposedly meant just for stainless. It's described as "full density". It is quite a bit thicker than "normal" tape. I personally didn't like it. It seemed to push out of the joint. But I wasn't dealing with loose joints like you are describing. Point is, this thicker tape might work for you

So I should clean the loctite 2046 off the loose fittings, thoroughly thread them with teflon, cover the teflon with that loctite 567 stuff (or was it pipe dope?) and, once cured, it'll be sealed, and locked/tight as all get-out?

 

[2grit]

So I should clean the loctite 2046 off the loose fittings, thoroughly thread them with teflon, cover the teflon with that loctite 567 stuff (or was it pipe dope?) and, once cured, it'll be sealed, and locked/tight as all get-out?

Loctite 567 is a pipe dope. thread sealant, whatever you want to call it. It's a trade thing, we call it all "pipe dope". Answer this question, are the fittings that are so loose, used or hand cut or are they factory new?

 

[aangel]

Loctite 567 is a pipe dope. thread sealant, whatever you want to call it. It's a trade thing, we call it all "pipe dope". Answer this question, are the fittings that are so loose, used or hand cut or are they factory new?

I'm uncertain about the 567 stuff. Compared it with 2046:

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/DF25E134F03D909B882571870000D81B/$File/567-EN.pdf

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/A006D6DAF94ED931852574FE0073D8E9/$File/2046-EN.pdf

It reads that Loctite 567 has >15lbs/inch adhesive torque, and 2046 has 18-160lbs/inch adhesive torque depending on how it's measured.

With that in mind is there a point in trying the 567 stuff? It sounds weaker than what I already have?

Another question about PTFE tape + threadlocker/sealer: wouldn't the PTFE tape basically provide an easily-ripped, slippery surface against the pipe dope? If the fitting is female steel -> threadlocker -> ptfe tape -> male steel, wouldn't the pipe dope and ptfe tape just basically slip-slide on eachother and not provide a lot of strength? I was imagining the threadlocker stuff works like this: female steel -> threadlocker -> male steel, and the threadlocker chemically bonds in some way to the steel and to itself, almost like a solvent glue?

 

[FuzzeWuzze]

As I said earlier, I've used upwards of 10 wraps trying to get these fittings to play nice. I have lousy parts of different steels (316/304) and different thicknesses from different manufacturers.

Also, tape creates a good seal IF you tighten the fitting fully. Some of my fittings need to be oriented in certain directions (see picture of my manifold as it dries). Honestly I should probably be using triclamp but can't afford it.

This problem is IMHO the main reason to buy 3 piece ball valves..you never have to worry about orientation when its threaded on...thread it on as tight as you can to the closest 1/4th so its flat and then just take the bolts off and move the handle where you want it and bolt it back on lol.

 

[aangel]

This problem is IMHO the main reason to buy 3 piece ball valves..you never have to worry about orientation when its threaded on...thread it on as tight as you can to the closest 1/4th so its flat and then just take the bolts off and move the handle where you want it and bolt it back on lol.

Works great for valves, not so great for 3-way tees.

 

[GHBWNY]

I'm a pipefitter by trade and this is how you will never get a leak. Buy some Loctite 567 thread sealer (not cheap but works best of anything I've ever used). It is food grade. http://henkelna.com/us/content_data/140389_LT5086_FoodBevTL_Brochure_LR.pdf

Apply 3-4 wraps of Teflon tape to the male threads. Apply Loctite 567 to the male and female threads. Be sure the Loctite is applied all the way around the fitting leaving no dry empty spots. You only need apply to the first 3 or 4 threads. Tighten the joint but not overtighten. You just don't need to overdo it with this stuff. It is really that good. Loctite gave a demonstration showing how good their product is. They actually hand tightened the joints and no leaks. I don't recommend this because it's not always an ideal situation. Their demonstration uses factory fittings. I use factory also but have to thread my own most of the time and sometimes the threading dies are a little dull. I still never get a leak with this stuff.

Loctite says you don't need Teflon tape. Trust me, with stainless steel, use it. I've threaded thousands of stainless joints and it will gall.

The nice thing with this stuff concerning the OP's header he is building is that he wants to orient the valves just so. With stainless, it is challenging to not gall the threads in the process of getting everything tight enough to not leak. Use the Loctite, tighten liberally and it doesn't leak.

I probably sound like a Loctite salesman. Trust me, I'm just a huge fan of the stuff.

Loctite 567 is the recommended sealant for stainless but works
on all metals. Hope this helps. Let me know if I haven't answered all questions

Truth or myth? --- I've heard that Teflon tape should not be used where a valve is involved, theory being that as the thread tightens, the tape can shred and pieces can eventually break loose and lodge in the valve parts.

 

[aangel]

Truth or myth? --- I've heard that Teflon tape should not be used where a valve is involved, theory being that as the thread tightens, the tape can shred and pieces can eventually break loose and lodge in the valve parts.

http://henkelna.com/us/content_data/142872_Thread_Sealing_101_Tech_article.pdf

In some environments, it is indeed contraindicated. On the other hand, I'm pretty sure most homebrewers use ball valve with NPT fittings, and use PTFE tape for those fittings, without any ill effects.

 

[Stealthcruiser]

When using the teflon tapes, leave the first couple of threads "presenting" themselves, to insure you have none hanging past the end of the male threads.
This means no "flappy" piece that can "work" back and forth under liquid flow, and become dislodged, to wind up elsewhere in the system, ( any system).

 

[2grit]

I'm uncertain about the 567 stuff. Compared it with 2046:

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/DF25E134F03D909B882571870000D81B/$File/567-EN.pdf

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/A006D6DAF94ED931852574FE0073D8E9/$File/2046-EN.pdf

It reads that Loctite 567 has >15lbs/inch adhesive torque, and 2046 has 18-160lbs/inch adhesive torque depending on how it's measured.

With that in mind is there a point in trying the 567 stuff? It sounds weaker than what I already have?

Another question about PTFE tape + threadlocker/sealer: wouldn't the PTFE tape basically provide an easily-ripped, slippery surface against the pipe dope? If the fitting is female steel -> threadlocker -> ptfe tape -> male steel, wouldn't the pipe dope and ptfe tape just basically slip-slide on eachother and not provide a lot of strength? I was imagining the threadlocker stuff works like this: female steel -> threadlocker -> male steel, and the threadlocker chemically bonds in some way to the steel and to itself, almost like a solvent glue?

You're comparing apples with oranges. 567 is pipe dope. 2046 is thread locker as in nuts and bolts. You're beating a dead horse here. I can see why people just give up trying to help AND you've still never answered my question. I do this stuff for a living and am damn good at it. I specialize in stainless and love working with it which is why I was so willing to help. I will say again, when you seal threads with 567, it is a pain in the a@# to unthread later.

 

[2grit]

Truth or myth? --- I've heard that Teflon tape should not be used where a valve is involved, theory being that as the thread tightens, the tape can shred and pieces can eventually break loose and lodge in the valve parts.

I'm assuming you mean ball valves etc. and this is total myth. The places to avoid Teflon tape is in gas piping, upstream from a gas valve, where a free floating piece of Teflon can plug an orifice. I've also done a lot of air controls and in many cases I avoid Teflon tape where a free floating piece of tape can plug an air control. I hope this answers your question

 

[aangel]

You're comparing apples with oranges. 567 is pipe dope. 2046 is thread locker as in nuts and bolts. You're beating a dead horse here. I can see why people just give up trying to help AND you've still never answered my question. I do this stuff for a living and am damn good at it. I specialize in stainless and love working with it which is why I was so willing to help. I will say again, when you seal threads with 567, it is a pain in the a@# to unthread later.

Sorry for not answering before. The fittings are a mix: 304SS 1/2 NPT tees, nipples, and camlock adapters that I bought new and have used (with teflon tape) for the past year's brewing. Also, some new 304SS 1/2 NPT tees, hose barbs. Also some new (and these are the problem) 316SS 1/2 NPT nipples, that don't seem to play very well with the others. I screwed some into ball valves (with 6-8 wraps of teflon) and they screwed *past* the end of the thread! Finally some 316SS ball valves I've threaded them together (using teflon tape) a few times now with varying results. Some of them I threaded on so tight they've locked up and I just have to use as-is, fused to the valve I originally screwed them into.

Regarding the 567/2046 stuff: sorry for doubting you. I don't really understand the difference between threadlocker and pipe sealer. They honestly sound the same to me. Pipe dope is another confusing one - I read that it's intended as a lubricant and not an adhesive, so how can it do both? There's also a the "I can't get this stuff in Canada, and it already took me a month to get the 2046 from the states, and the 2046 was super pricey, so I'm doubling down on checking specs." Please don't take it to mean I'm questioning your expertise, I just really don't understand the subject matter.

I'm going to make a short video tonight of my pipe/valve manifold. Maybe showing just how loose/poorly fitted together these fittings are may help.

 

[GHBWNY]

I'm assuming you mean ball valves etc. and this is total myth. The places to avoid Teflon tape is in gas piping, upstream from a gas valve, where a free floating piece of Teflon can plug an orifice. I've also done a lot of air controls and in many cases I avoid Teflon tape where a free floating piece of tape can plug an air control. I hope this answers your question

Yes, thank you.

 

[aangel]

so here's the video showing the plumbing manifold.

 

[Ozarks Mountain Brewery]

thanks, just a tip its much easier to add one piece at a time, tighten with vice grips and a crescent wrench is what works for me, add a liberal amount of Teflon tape make sure its in the correct direction and tighten as tight as you can then give it some elbow grease to move it in the right position instead of loosening