It might be a transition from threaded galvanized water pipes to copper pipes or from old cast iron sewer lines to today s abs.
Galvanized pipe to copper transition.
Cut copper pipe just above the corroded connection using a tubing cutter.
Solder the brass half to the copper pipe thread the steel half onto the galvanized steel pipe with teflon tape then join the two together tightly with the joining nut.
Benefits of galvanized pipes.
Plastic pipes are usually black and clamps should be visible.
Use two pipe wrenches to loosen the old union.
This eventually causes pipe degradation and leakage.
You don t need to wrap plumbing tape around the union before you screw it together.
The fitting is generally made of galvanized steel and bronze.
If the surface of the pipe is the color of a penny then the pipe is probably made from copper.
It s far easier to make a repair to steel pipe with copper than with galvanized plumbing pipe because the galvanized calls for cutting threads on exact lengths of pipe.
Tighten first with pliers then with pipe wrench.
Find the area where pipes enter your home and carefully scratch the pipe with a nickel.
Install the lower half of the dielectric union to steel pipe.
Eventually galvanized pipe will have to be replaced and when that happens your choices are to replace it with more galvanized pipe copper pipe or plastic pipe.
Since brass doesn t react with either the copper or the zinc one method is to make sure you have a threaded female end on both the copper and the steel pipes and then connect the two by simply inserting a short threaded brass nipple between them the second method is to use a special transition fitting called a dielectric union.
The problem with galvanized pipe is that it reacts with the minerals in the water supply.
The inside of galvanized pipes gets thinner over the years.
When water flows through pipes of two different metals the pipes will become eroded by electrical impulses from the slight acidity found in all water sources.
This fitting joins a copper pipe to a galvanized pipe called a union.
Remove the old union from the steel pipe.
Making the connection between plastic pipes such as abs or.
And the male ends where the threads were cut into can become so thin that they leak when you try to screw on a new female fitting over the end of them.
So try to make the transition at an existing female fitting.
Wrap threads on end of the steel pipe with teflon tape.