Union removal and replace

[C. Moore]

Hi. What is the best way to remove this copper fitting from cast iron?

Also, should I try and replace it with the same or can i use something else?

Thanks

 

[Terry]

We use pipe wrenches on those. Sometimes you want one with a long handle. Or a pipe over the handle to extend the leverage.
Depending on codes, copper DWV, ABS, PVC,
You have several choices there.

 

[Sponsor]

 

[C. Moore]

Thanks. I'll give it a go.

 

[FullySprinklered]

The connection doesn't appear to be an actual "union", that being a particular fitting that one would use to make repeated disconnection and reconnection without cutting pipe. The big wrench is a good idea, but if you're not getting results, get a torch and put some heat on it. It'll go.

 

[C. Moore]

Thanks for the tips. I was able to use heat along with the pipe wrench to make progress. Unfortunately, part of the thread broke off inside.
Is there a way to remedy this without cutting the cast iron?

 

[Cwhyu2]

Inch and a half IPS tap will clean out the threads, you should be able to rent one at your local tool rental shop.

 

[C. Moore]

Thanks, I'll let you know how it goes.

 

[FullySprinklered]

Might be able to deconstruct the threads remaining in the fitting with a hammer and a narrow sacrificial chisel. Sometimes if you can get them going you can peel them out like a sardine can and key. Get something sticking up and grab it with needle-nose pliers, then start twisting it around.