Someday I am going to have to replace my water heater and want to be ready. I live in Illinois and the stupid code won't let me use the yellow flex lines. I've never worked with black gas pipe before. I work with gas lines at work (Gas Chromatography Chemist) but it is all 1/16", 1/8", or 1/4" steel or copper with swagelok fittings. One thing I can't figure out is when you have a fitting like an elbow or valve that has to be in the exact correct orientation how do you know when to stop turning rather than go for a full additional rotation.
Working with black gas pipe when to stop tightening
- Thread starter sschoe2
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It's a feel thing. It helps when you have done a few to know how far they thread in and how tight it feels. You may want to practice with some that you're not using to see how far they thread in.
And every pipe nipple is threaded slightly different.
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Jadnashua
Retired Defense Industry Engineer xxx
What you use for the thread sealant will also make a difference on how easily the thing turns. PTFE tape is a really good lubricant, and while it might seal things, you can often tighten it more than necessary. Some people use a combination of the tape and pipe dope. A pipe thread is tapered, so it's not like tightening a nut on a straight thread. How far you have to tighten it depends on how the pipe was threaded, the quality of the job (mostly, how sharp the die was). If the threads are torn from a dull die, it may take a bit more tightening to wedge enough of the tape or pipe dope into the gaps to seal things. The good thing is that the pipe and fittings are generally strong enough so you can actually tighten it more than you think you should (but probably don't need to).
There's probably a union in the mix, so, you can just unscrew the coupling nut, and take the parts apart. It doesn't hurt to put a little pipe dope on the mating parts, but it should not be needed. If the fitting was overtightened, though, it might have created a slight ridge, and if it doesn't line up, it can leak...the pipe dope can help.
There's probably a union in the mix, so, you can just unscrew the coupling nut, and take the parts apart. It doesn't hurt to put a little pipe dope on the mating parts, but it should not be needed. If the fitting was overtightened, though, it might have created a slight ridge, and if it doesn't line up, it can leak...the pipe dope can help.
wwhitney
In the Trades
My practices as someone whose gas experience is limited to two house repipes:
- Use only Rectorseal 5 for thread sealant. That's what the local gas company uses.
- Tighten each joint hand tight plus 1-2 turns. For a fitting that has to point in a particular direction, I might instead go with 0.8 - 1.8 turns, as getting to 2 full turns can be really hard. It depends on how the other joints have gone.
Cheers,
Wayne
- Use only Rectorseal 5 for thread sealant. That's what the local gas company uses.
- Tighten each joint hand tight plus 1-2 turns. For a fitting that has to point in a particular direction, I might instead go with 0.8 - 1.8 turns, as getting to 2 full turns can be really hard. It depends on how the other joints have gone.
Cheers,
Wayne
I agree with Rectorseal 5
No Teflon tape UNLESS it is approved for gas work and white teflon is not
On a written the the question was how tight to make up a threaded fitting
The correct answer is 3-5 turns hand and 2 turns using a wrench
No Teflon tape UNLESS it is approved for gas work and white teflon is not
On a written the the question was how tight to make up a threaded fitting
The correct answer is 3-5 turns hand and 2 turns using a wrench
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