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-   -   No new dope on gas leak fix, how long will it last? (http://www.diychatroom.com/f17/no-new-dope-gas-leak-fix-how-long-will-last-157741/)

Super Mario 09-23-2012 03:41 PM

No new dope on gas leak fix, how long will it last?
 
I recently had my gas pipe fixed. The contractor took apart, redoped and put back together several leaking/loose couplings. There is one leaking pipe-coupling connection where he could not remove the pipe, so he only retightened the pipe one full rotation without applying any new dope.
My question is how long will this particular connection last? Is it likely that it will leak again in the near future because of the lack of new dope?

how 09-23-2012 05:39 PM

If he could get a full rotation on the pipe that was leaking, it sounds like the pipe was loose. If that pipe was originally doped and was only loosely tightened, then fully tightening is an acceptable practise if it then stops it from leaking.

hvactech126 09-23-2012 06:25 PM

Pipe dope is only for lubricating the threads to allow the pipe to be tightened enough to seal. The pipe dope does not actually seal the pipe.

carmon 09-23-2012 06:54 PM

Quote:

Originally Posted by hvactech126 (Post 1015935)
Pipe dope is only for lubricating the threads to allow the pipe to be tightened enough to seal. The pipe dope does not actually seal the pipe.


I concure. it will be just fine...

Super Mario 09-24-2012 08:40 AM

Thanks guys.

Wiscbldr 09-24-2012 11:34 AM

To verify all the leaks were property fixed, have your local utility come out with a hand "sniffer" and check for leaks. Better to be safe than sorry!....

techpappy 09-24-2012 11:45 AM

According to wikipedia..."pipe dope" is both a lubricant and a sealant. Just interesting but not really pertinent to this thread?


http://en.wikipedia.org/wiki/Pipe_dope

raylo32 09-24-2012 01:51 PM

Most references I have seen say that the variation and coarseness of pipe threads require dope to get a positive seal. I am not a pro and in the few gas jobs I have done I have had only one leaking joint (tiny, tiny leak) and it did not respond to extra tightening. I had to take it apart and redope it. But like the guys say, the real test is if it is leaking or not. If not, you are good to go.

Super Mario 09-24-2012 02:29 PM

Quote:

Originally Posted by raylo32 (Post 1016495)
Most references I have seen say that the variation and coarseness of pipe threads require dope to get a positive seal. I am not a pro and in the few gas jobs I have done I have had only one leaking joint (tiny, tiny leak) and it did not respond to extra tightening. I had to take it apart and redope it. But like the guys say, the real test is if it is leaking or not. If not, you are good to go.

They checked it, it's not leaking now. I'm not sure how long the fix will last though

danpik 09-24-2012 04:53 PM

Every gas leak I ever repaired was due to someone relying on the pipe dope to seal the joint and not tightening the joint enough, Don't loose sleep over this...you will be long gone before it ever leaks again if it was tightened properly.

Marty S. 09-24-2012 05:07 PM

The male ends of the pipe are slightly tapered so if it's tight it won't leak. Don't worry about it.

Super Mario 09-25-2012 01:57 PM

You guys are awesome, I appreciate the help.

beenthere 09-25-2012 05:03 PM

Except for electrical conduit. Pipe threads are tapered, both the male and female threads, they form an air and liquid tight metal to metal seal without a sealant. Pipe dope, or thread lubricant is needed to reduce friction while tightening.

Thread sealants are used/needed on non tapered threads to make them air and liquid tight.

PS: Some electrical companies do use tapered threads, but it is not required.

Missouri Bound 09-25-2012 09:08 PM

Quote:

Originally Posted by techpappy (Post 1016413)
According to wikipedia..."pipe dope" is both a lubricant and a sealant. Just interesting but not really pertinent to this thread?


http://en.wikipedia.org/wiki/Pipe_dope

Wikepedia is a pseudo encyclopedia...it's full of opinions and half facts.

Hardway 09-25-2012 09:40 PM

The hell they will seal, pipe dope is need to seal the pipe tthreads on gas, water and air! The threads are tapered so they tighten up. If pipe dope was just to lube the threads, the cutting oil would do to seal the joint!


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