One-inch gas black pipe leaking

Is there a trick to keeping one-inch gas black pipe from leaking?

I have a contractor who did his own house with no problems. But he used half-inch black pipe rather than one-inch.

I need to use one-inch in order to keep the inspector happy because I'm teeing off the one-inch that goes to my cooktop so that I can feed a 3/4 inch pipe for a fire pit.

My contractor seems to be doing everything right. He's using pipe dope and is tightening things down. He may be overtightening ... but if he doesn't tighten as much as he does then things leak.

He's super-frustrated because he's spent four days on only thirty feet of pipe. There are eight elbows in that run. He's not charging me for his time (because, he says, that he should know what he's doing) but since he's a friend I don't want to ream him. He's done a superb job on electircal and water plumbing and carpentry and he's been paid well ... but, still, he's a friend.

So some general questions:

a) Does one apply pipe dope to both the inside and outside threads?

b) Does one-inch pipe need to be tightened more than half-inch?

c) Can fittings be used more than once? Do they need to be totally clean if being reused?

d) If the joint leaks and tightening doesn't solve the problem and the joint continues to leak, what should we do?

Try the yellow made-for-the-purpose gas pipe tape AND pipe dope.
The pipe dope and tightening should be doing it, but who knows.
Good luck!
Mike
(I'm not a pro, but that's what I do.)

Do you put the tape down first or the dope down first?

If you try putting the dope down first, you'll know pretty quickly which way is right . Do the fittings by any chance have "CHINA" on them?

Mikey said:

If you try putting the dope down first, you'll know pretty quickly which way is right . Do the fittings by any chance have "CHINA" on them?

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It's Home Depot stuff so it is likely Chinese. At least the one part that I can see has China stamped on it.



Getting back the the doping/tape question: I could

a) put a very thin film of dope on the threads followed by the tape.

b) Put the tape on the threads and the dope on the fittings.

c) Put the tape on first and then glob on dope on the tape.

d) Put the tape on the threads and the dope on the fittings.

Lot's of possibilities.

Think about sweating pipe. There is really only a single right way to clean, flux, and apply heat to the joint.

Is there a single right way to apply dope and/or tape to one-inch pipe.

Tape then dope, I think...

I suspected the fittings (China, eh? No wonder.).
Right. Tape, wrapped flat clockwise only as the threaded end faces you, then dope.
Mike

check fittings and DYES

what kind of DYES are you useing????

Rigid or some cheap knock off....

Like the guy before me said.....go to a plumbing supply house

and spend a few dollars more and get good fittings.....

and maybe check out your thread makeing equipment

Repiped my house's gas line...used a Chicom pipe die set (which has a visually-obvious greater taper than the factory gas pipe from Home Depot), Home Depot green-PVC-coated pipe and galvanized pipe, and Home Depot fittings.

Yes, larger pipe requires more torque than smaller (all things being equal).

I was fanatical about tightening mine, because I had to cut & fit many angles, and didn't want to have to take it all apart.

End of story: easily passed the leakdown test.

Torque those fittings REAL tight - you aren't going to break them...

BTW, dope or tape...not both....

The threading machines in the HD don't get adjusted very often. And unless that store has someonw who even knows the difference, the cutter set never gets replaced. You see the threader tearing up the pipe quite often....a product of dull dies and cheap pipe/ Also, the auto-release die chuck that they use tends to cut shorter threads than factory specs/

A black fitting should be spun hand tight 3-1/2 times. Any more, the taper isn't big enough. Any less, the taper is too big.

Pressure to use to test black pipe?

Kman said:

End of story: easily passed the leakdown test.

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So what pressure do you use to test black pipe?

I had my contractor pump things up to 80 pounds so that we could see any leaks. At 80 pounds it takes 15 minutes to drop to 40 pounds.

The section of code that the city gave me made no sense at all. I could, if you guys want, quote it here.

thats pretty high

when we test for gas leaks, I NEVER pump up
the lines more than 10 lbs....

on old stuff if you were to pump up the system that high --80 lbs
you can guarantee that you will make a few new leaks of your own
while doing it....

the gas company uses a mananometer to test our work and

they usually just blow an ounce or two of ait into this pipe..

the gas pipe is never under much more than a few
ounces of pressure throughout its whole life


try putting 5 lbs in the pipe an slet that sit for a while....

master plumber mark said:

when we test for gas leaks, I NEVER pump up
the lines more than 10 lbs....


try putting 5 lbs in the pipe an slet that sit for a while....

Click to expand...

According to my licensed HVAC guy, the city inspectors insists on a test of 20 pounds for twenty minutes with no loss of pressure.

The pipe we are testing is all new pipe connected to a relatively new shut-off that connects to the rest of the house.

By the way, in terms of buried flex pipe, the city inspectors insist on sixty (or is it eighty?) pounds.