How to Change Galvanized Plumbing

Shut off the main water line by turning the ball valve on the main line 90 degrees clockwise.

Grip the base of the nut connecting the section of galvanized steel that you want to replace, using channel-lock pliers. Turn the nut counterclockwise until loose.

Place the pliers around the nut at the top of the pipe being replaced and turn the nut counterclockwise until loose. This removes the connection at either end of the steel pipe.

Pull the pipe out of the top and bottom nuts. Water may rush out of the system, so be prepared to mop up spilled water with a shop vacuum or towels. Repeat the process for any additional sections of pipes you are removing.

Unthread the nuts from the top and bottom fittings where you removed the pipe. Discard the nuts.

Place a new dielectric union on the pipe nipples on either side of the open ends of the pipes. Tighten one end of the union to the nipples using the channel-lock pliers. The dielectric union will prevent the new material from coming into physical contact with any remaining steel fittings, which can lead to corrosion due to low electric currents the differing materials create.

Insert the new sections of pipe between the union fittings. Copper is the preferred material in many plumbing codes, but some areas may also allow materials such as CPVC.

Tighten the ends of the unions over the new pipe using the pliers.

Turn on the main water line to test the new pipes. No water should spray from the union fittings. If water does leak, tighten the fittings further.