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paulz
Member
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# Posted: 2 Feb 2017 12:30
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Can't get these to pass the soap test. I've lightly sanded them clean, no obvious boogers. Any tricks?
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DaveBell
Moderator
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# Posted: 2 Feb 2017 12:55 - Edited by: DaveBell
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Yellow Teflon tape, AKA Gas Tape. Wrap with threads, not against. Try minimum wrap to start, like 1.5 turns, usually doesn't take much.
Edit: got my colors wrong.
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Nate R
Member
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# Posted: 2 Feb 2017 13:13
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No, no teflon tape on this joint, I believe. The threads on these fittings are not tapered and not meant to seal, but the brass face is the sealing surface, if I'm not mistaken.
Are you putting both of those fittings at different times into the same tank? Is it the tank side that's bad, maybe?
Sometimes the fittings are bad right out of the box, too. The taper isn't right, etc. Many of them now use O-rings instead, easier/cheaper to make work, but don't last as long.
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Nate R
Member
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# Posted: 2 Feb 2017 13:15
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Also, on that note, I MUCH prefer pipe dope vs teflon tape....no issues of it sliding off the threads, easier to work with, etc.
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sparky30_06
Member
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# Posted: 2 Feb 2017 13:16
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DO NOT USE ANY TYPE OF SEALING TAPE OR PASTE!!!!!
those fitting seal on a crush face not threads. use some fine scotch brite to clean them up. If they continue to leak on of them is bad
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bobrok
Member
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# Posted: 2 Feb 2017 13:48
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You've all confirmed my first thoughts on OP
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Cowracer
Member
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# Posted: 2 Feb 2017 15:54
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I've seen those type just not seal for no particular reason from time to time. Common on welding stuff. I guess they get crushed slightly out of round or something.
Nothing I have ever found will fix them, except buying new
Tim
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DaveBell
Moderator
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# Posted: 2 Feb 2017 16:47 - Edited by: DaveBell
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Yellow Teflon Gas Tape..
https://www.amazon.com/gp/product/B000L8BHD0/ref=as_li_tl?ie=UTF8&camp=1789&creative= 390957&creativeASIN=B000L8BHD0&linkCode=as2&tag=smacab-20&linkId=ZAPABZOQERSRGUED
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Malamute
Member
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# Posted: 2 Feb 2017 17:20
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Previous comments about NOT using tape or sealant on that type fitting are correct. Same for compression fittings, the threads are NOT the sealing surface. Sometimes some lubricant on the threads or shoulders of threaded fittings allow the fittings to move without squeaking and binding, but the threads, again, are NOT the sealing surface.
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MtnDon
Member
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# Posted: 2 Feb 2017 18:15 - Edited by: MtnDon
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Quoting: DaveBell Yellow Teflon Gas Tape...
...is great for taper threaded pipe fittings. Never used on compression or flare fittings as malamute and others have noted.
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bldginsp
Member
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# Posted: 2 Feb 2017 18:44
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I've used pipe dope on pipe unions with success. They seal the same way- metal face against metal face. I don't know why people say not to use it on flares and compression. Might be a good reason but I don't know what it is.
Sanding the surface could cause leaking two ways- the gas could leak through scratches, or the sanding could distort the round shape of the mating surface face.
I agree with Sparky to burnish it with scotch brite, then I would put a VERY thin layer of pipe dope on the male end, none on the female. You don't want any squeezing out on the inside. Works wonders on unions, but don't put any on your onions.
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paulz
Member
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# Posted: 2 Feb 2017 19:31
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I have experience annealing copper sealing washers, heat cherry red and cool. Go from rock hard to pliable, I wonder if brass would act the same?
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MtnDon
Member
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# Posted: 2 Feb 2017 19:45
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The manufacturer (Brasscraft) instructions on the water heater flex line I just used, came with instructions that stated to use no sealants of any kind on the flare. Where the flare fitting was assembled to the pipe threaded portion they indicated to use gas pipe teflon or a pipe dope sealant.
Brasscraft also stated that the use of food safe mineral oil may be used on the threads on compression fittings or flare fittings in order to facilitate tightening and possible future dismantling.
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bldginsp
Member
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# Posted: 2 Feb 2017 22:30
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I just googled using dope on flares. Many plumbers do it, equal numbers say not to. The best argument I found for why not to is that dope on a flare will only temporarily stop a leak. Flare and compression fittings are intended to be metal on metal, if it leaks, that has not been achieved. If you dope it, you still don't have metal on metal everywhere and if the dope leaves you get a leak.
Not sure I believe that. Where is the dope going to go? It's made to stay.
Other arguments against dope on flares are that dope or tape in the tube could find its way to an orifice and clog it, or to a valve and damage it. But gas is under such low pressure the likelihood of the dope moving through the tube is low.
One argument in favor of dope on flares, and they stressed using only the slightest amount, is to lubricate the flare end so that it seats well on the fitting end as it is tightened.
I think I will use no dope on the flares for my propane lights, and if I find leaks, I'll tighten the joint, if that fails I'll replace it.
I will continue to use dope on unions, as all plumbers do.
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DaveBell
Moderator
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# Posted: 2 Feb 2017 23:13
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I'm not sure the threads are correct.
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Jebediah
Member
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# Posted: 3 Feb 2017 06:46
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Back the male fitting off about a 1/4-1/2 turn, retighten, do this in rapid succession about 5-10 times, sometimes this works.
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sparky30_06
Member
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# Posted: 3 Feb 2017 06:49 - Edited by: sparky30_06
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these joints are designed to seal on the mating face. no tape or dope should be used. over time it will allow gasses to escape. Talk to anyone in the flammable gas industry, anyone that works with oxygen, hydrogen and many other flammable gasses and they will tell you tape or dope is a BIG NO NO!
bldginsp
"I will continue to use dope on unions, as all plumbers do."
Don't know where you are inspecting but when I was building houses, if a plumber did this, the inspector would fail it.
I work assembling tubing and pipe for services rated up to 60,000 psi. We do under 15K in our sleep. Trust me, is it's leaking get a new fitting, a quality fitting. Propane sinks and collects when it leaks, nothing to mess with. Unless you want a bunch of match sticks after the explosion.
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bldginsp
Member
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# Posted: 3 Feb 2017 08:37
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The unions I was talking about were brass unions in water piping, of which I have a lot for my poly piping system around the property. Dope is the only way to stop them leaking.
I wonder why it is that dope would cause a leak on a flare connection, but not on a threaded connection.
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toyota_mdt_tech
Member
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# Posted: 3 Feb 2017 08:55
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Quoting: bldginsp I think I will use no dope on the flares for my propane lights, and if I find leaks, I'll tighten the joint, if that fails I'll replace it.
bldg has it right. Sealing the threads on this fitting isnt where the seal comes from, that just is used for the clamping force. I would say the OP has leaks on both fittings, the booger may be on the receiving end????
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TerraLove
Member
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# Posted: 3 Feb 2017 11:37
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Quoting: DaveBell Yellow Teflon tape, AKA Gas Tape. Wrap with threads, not against.
How are you proposing to use teflon tape on a POL fitting, where its threads are on a bushing which freely rotates around the stem? The stem head has to seal against the orifice bottom, not the threads. No tape should be used on the POL fittings!
Sanding the head is probably what is causing the leaks. Throw away this fitting, buy another one.
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paulz
Member
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# Posted: 3 Feb 2017 12:41 - Edited by: paulz
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Sanding did not cause the leaks, if it didn't leak in the first place after several attempts I wouldn't have cleaned it up. And I'm not talking about holding them to a belt sander. A couple of twists by had with 300 grit just to take off the surface corrosion. But yes, time to buy a new fitting.
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bldginsp
Member
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# Posted: 3 Feb 2017 14:16
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Perhaps the most important thing to remember is not to conceal any flare or compression fittings, or unions, inside walls, floors, or ceilings. Tubing can run through hollow walls with 8" nail plates over studs, plates etc. where the tubing passes through. Tubing in walls should always be single runs with no joints unless brazed. This way you can readily check any fitting for leaking with a soapy water test.
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Castanet
Member
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# Posted: 7 Feb 2017 08:27
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I occasionally find damage on the male domed sealing face of a propane regulator. This is usually caused by careless placement of the detached regulator while moving the old bottle out and the new bottle into position. If the regulator falls or swings down on its hose and strikes a hard object then a dent can be caused in the domed face. When a dent occurs a "crater" is formed with raised displaced material at its periphery. The same thing happens when using a centre punch. All it takes is a light impact.
No amount of tightening will clamp that raised material down flat again and will only cause other damage. If the dent has not caused a continuous leak "trench" radially across the face then it can hopefully be reclaimed. The dent needs to be dressed with a fine diamond stone to remove ONLY the displaced brass to level with the original surface, NO LOWER. Do not cause a flat. It is not necessary to get rid of the dent itself as this will cause a flat. Hopefully if the dent was small enough then there will be enough remaining surface to get a satisfactory seal. Only remove that material which is proud of the original surface. When using abrasives in an emergency in the field then work in a rotating or tangential direction. Any scratches will then be perpendicular to the leak path. Do not use a third component of any sort to make a seal. It has been known for fragments of tape or even hylomar residue to find its way into places where it shouldn't go. Wipe away all grit.
finally CHECK AND RE-CHECK with bubble solution. Get the juice right around the join at the thread end and where the nut spins on the pipe as the gas can come out either route. Use a small paintbrush to load the interface with a continuous wetting all the way around.
Furthermore as another bit of the service make sure that the regulator's atmosphere-side breather is clear. Some aluminium bodied regulators can get that white alu corrosion that blocks the hole.
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neckless
Member
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# Posted: 24 Feb 2017 04:12
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that was fun to read LOL
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ColdFlame
Member
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# Posted: 24 Feb 2017 10:10
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Castanet You located in BC by chance? Your username piqued my interest.
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