How to remove steel nipple from brass tee?

What are the tricks to remove a steel nipple that connects a brass tee to a brass shut-off valve without breaking it off?

We've got those here and there. They all look solidly rusted in place for eternity but there comes a point where a valve needs to be changed out. I know, steel on brass/copper should not be but that's what the contractors did decades ago.

Regards, Joerg

sometimes you have to use the old torch method...
that and penetrating oil sometimes work....

pipe

Unless it is already at the point where it has rusted out, it will usually unscrew using the proper sized pipe wrench.

Ok, thanks, guys. The torch method would be very scary here because these connections are often really close to or in between wooden beams. Metal shielding would work but it'll still be a white-knuckle job when you are on your back with the upper end of the crawl space just inches from the teeth. Even with a garden hose right next to you.

Regards, Joerg.

If it is a short nipple, it usually helps to have something like a cap or other fitting on the free end to keep it round when applying the wrench.

If you are saving the tee you should also have something screwed into the other ports when applying the wrench to the tee.