Thread 3/4 black pipe in place

[Dave]

I have to move some 3/4 "gas plumbing that is 20+ years old. Basically it sticks out too far into the kitchen so need to move it back a couple inches. Normally I would just remove the piece and replace it with a shorter one. The problem is the piece goes back into the firewall and I get a wrench on the 90 elbow.

I don't want to torque the pipe.

Can the pipe simply be cut and threaded in place using a pipe thread ratchet? My other option is to demo the firewall.

[Speedy Jim]

The threader itself will put significant torque on the pipe. That alone may create a leak back in the wall. Hmmmmmm

[BobK207]

How far does the pipe stick out?

The pipe threader will need at about 3" clear to the wall to create the new thread.

Threading the pipe will "tighten" the pipe into the elbow; but there is a chance that this will cause a leak.

I'm not sure how I would approach this situation..........

If the 3" protrusion was ok I might go for the "cut & re-thread" option but you'd have to be able verify "no leak" inside the wall.

Another approach would be to remove the offending pipe, use a job saw, jig saw or large hole to cut an access hole. Install the new (shorter) pipe w/ valve & test for leaks.

Replace the wall piece that was removed.

cheers Bob

[Wayne Whitney]

Just thinking out loud here, with no particular experience: if there is enough clearance from the wall, is there a way to clamp the pipe sticking out of the wall so that the torque from the threader will not be transmitted to the fitting inside the wall? Maybe just a long pipe wrench and a helper to provide an opposing torque as needed?

Cheers, Wayne

[Dave]

I ended up busting through the fire wall. It took a good while, but it seemed like the "right" way to go about it. I got it all done with a minor leak in the final piece. It is a 6" straight piece between 2

90's. I don't think it will be too hard to finish up tomorrow.

Does anyone have any techniques for putting in the final piece? I tried to get one side pretty tight then backed it off to screw into the other 90. I really don't see any other way to go about it.

Thanks for the help and suggestions!!!

[DT]

That's what a union is for. Your method absolutely will not work. If you have

6", a union and two short nipples should just make it.

-- Dennis

[Dave]

Thanks for the info DT!!! I will fix it tonight. :-)

[Goedjn]

Depending on how much of a stub-out you're leaving, you may be able to clamp some sort of holder to the pipe while you're threading it.

[BobK207]

It is never a good Idea to un-screw pipe threads (even a little bit to "fix" orientation of valves & such)

this will often result in a leak.

cheer