Galvanized supply pipe removal

I re-plumbed most of my basement about a year ago with CPVC and it has held up well. Up until now, I have been able to go around the existing galvanized supply lines without touching them but I finally have to cut into them due to a bathroom remodel.

I've read many times that the way to get into these pipes is to cut into them with a recip. saw and then use 2 pipe wrenches (one in each direction) to remove the pipe from the fitting. Looking at the threads where the pipe and fitting come together, there seems to be some corrosion or old hardned pipe dope or something other than clean threads.

If I manage to back this pipe out of it's fitting, what are my chances of being able to use the threads in the fitting again? The fitting that I need to work is a tee which is part of a riser going to the 2nd floor. If this fitting does not seal properly, I'm looking at tearing into many walls and floors to find a place to re-attach.

Steve

Steve,

Usually the fitting will be ok, go for it.

fitting

Your wrenches are not big enough, and you are not strong enough, to damage the fittings while removing the pipe from them.

Turns out you guys were correct.

This project required the purchase of a 14" and an 18" pipe wrench. Also, I had to squirt some penetrating oil on the threads and wait a few minutes. Once those few minutes were up, I put the 14" wrench on the fitting and the 18" one on the pipe. With every ounce of stregnth I could gather, I got the pipe to move.

In the next part of the project, I have to remove 3/4" galvanized instead of just the 1/2" that I just removed. Is the 3/4" going to be even more difficult?

Steve

Ir depends, but typically, the larger the galvanized pipe, the harder it is to break loose. Use larger pipe wrenches, and let the penetrating oil do its work.
You also can tap on the fittings with a hammer to help break them loose, and also you can first try turning the pipe "tighter" in the fitting to help break the threads loose before backing the pipe out.
Hold a backup wrench on the fitting, and put the one on the pipe close to the fitting when turning it out.
Good Luck!
Mike

pipe

IT depends. If the apprentice tightened the pipe it will probably be harder to unscrew. If the journeyman did it, you may not need the big wrenches.