Capping off a propane line: need tips and tricks!

[profdant139]

After great effort, I just now found my very slow propane leak (and I will soon prepare a fascinating 😉 report on the many things I learned while trying to find it). Bottom line – the leak is at the point that the external barbecue fixture connects to the propane system.

What I want to do is remove the barbecue fixture – we never use it. And I want to cap off the stub or nipple that "tees into" the propane line. The pipe is galvanized. It appears to have an ordinary pipe thread -- not a flared brass gas fitting.

I am planning to unscrew the existing reducing bushing (I think that is what it is called) and replace it with a galvanized cap. I will use teflon gas tape at that joint.

My real question is this: I don't want to put any stress on the other galvanized propane lines underneath the trailer. I will hold back on the galvanized nipple with a pipe wrench while unscrewing the existing reducing bushing. The bushing is very rusty -- I anticipate having to use a lot of force to unscrew it. I'm planning to spray it with WD-40 a day or so before unscrewing it, to try to loosen the threads.

Does this sound like the right approach? I am not a plumbing or propane expert, as you can tell.

Thanks in advance for your suggestions!!

[MrWizard]

i agree with the pipe dope on a capped line

tape can sometimes be a PITA to use

[Bobbo]

profdant139 wrote:
I'm planning to spray it with WD-40 a day or so before unscrewing it, to try to loosen the threads.

Contrary to popular belief, WD40 is not a penetrating lubricant! Get some PB Blaster. Best stuff on the face of the planet for what you are doing.

On a related note, personally, I prefer pipe dope to PTFE tape.

[MrWizard]

i prefer 'Kroil' or 'PB blaster' much better penetration, bushing will come out easier

I would use a Brass cap, and Yellow Teflon tape is for Gasses, white Teflon is for liquids

[Old-Biscuit]

YEP....
Always use 2 wrenches
1 to HOLD existing pipe and 1 to use to remove other pipe/nipple etc

Pipe dope the threads (yellow tape will work....several wraps)

[Chris_Bryant]

Should be black iron, not galvanized, but other than that, it’ll be fine.

[wrktfsh]

That’s how I would do it. Use pipe dope on the threads. Turn off gas first