The 2010 California plumbing code requires one to perform it with a union when pipes made of metals are joined by you. The plastic or rubber washer at a union keeps the pipes because an electric charge will develop between them that causes leaks and rapidly corrodes the metal. Older ones may simply have galvanized fittings, although most newer water heaters have dielectric unions pre-installed on the inlet and outlet ports. Installing a union to join other galvanized pipes in your house, as well as these , to copper requires both wrench and work.
Before you cut Switch off the water to your plumbing pipes or cut to them. Make sure it’s off if you’re hooking up a boiler or water heater, and drain the water.
Separate the two halves of a union. Notice that one side is threaded so that you can screw it onto the pipe that is galvanized, and one side has a brass slide connection so that you can solder it. Within these two halves is a rubber or plastic washer that keeps the pipes out of contact. Eliminate washer and set them apart.
Wrap pipes tape around the threads of the pipe and then screw it and the half of the union together. Tighten the fitting with a pipe wrench.
Remove the washer against the union’s nut and screw the union together hand tight with the half facing the copper pipe. Slip a copper coupling onto the pipe’s end and then measure the distance from the close of the coupling to the conclusion of the union with a tape measure. Insert 3/4 inch to your measurement to account for the amount of pipe that goes within both fittings.
Cut a length of copper pipe to the length you measured with a pipe cutter, then de-burr the ends of the pipe.
Remove the coupling and disperse soldering flux on both inlets of the coupling and both ends of the pipes that fit to it. Spread flux on the opposite end of the pipe and on the inside of the brass part of the union that you cut. Unscrew the union, then build the pipes.
Sweat all the copper connections. Then screw the union, when the washer cool, then replace within the nut of the union.