The reasons to install a water pressure reducing valve are to save water and also to reduce the wear and tear on your plumbing system from the water pressure being too high. You will want to install the valve as close as you can to the main water shut off.
Step 1 – Shut off the Water
Turn off the water at the main valve. Also turn off the water to the water heater. Also turn off the breaker for your electric water heater. If you have a gas water heater then turn it to “pilot”. Drain any water in the rest of the pipes by opening the faucets in the house.
Step 2 – Remove a Pipe Section
The valve is spliced into a section of the line so that the water flows in and out of the valve. Sometimes there is not room for all of the fitting so you can do a loop back installation. Cut out a segment of the main water line. Have a container nearby to catch any water that comes out.
Step 3 - Remove and Clean the Pipe
Wipe the cut ends of the pipe with the cloth. Clean the inside and outside of a 90-degree elbow, coupling and male adaptor.
Step 4 - Affix the Elbow
Put flux on the ends of the pipe and the fittings. Attach the elbow, the coupling and the adaptor.
Step 5 - Solder an Extension Piece
Solder to each joint.
Step 6 – Mount the Fittings
Unscrew the union from the reducing valve, mount to the fitting, and then screw into place. Use plumber's wrenches to tighten. Mount the valve. Put an extension on the threaded end then solder it all together. Now screw it back together.
Step 7 – Attach the Reducing Valve and the Union
Clean, flux and attach the adaptor to the extension piece. Solder the fittings. Let cool before handling. Twist the valve into the union. Be sure the fitting marked “in” is attached to the main water line. Tighten with a wrench.
Step 8 - Attach the Remaining Fittings
One elbow is fluxed and affixed to the reducing valve's extension. Now add a coupling. Next the second elbow is attached. Take the copper pipe and attach an elbow to it. Mount the fitting to finish the loop to the water line.
Step 9 - Solder the Joints
Be certain it is securely fastened and then solder all the joints.
Step 10 – Test the Line
Turn the water back on. Turn on the water heater. Open the main valve. Examine the piping for leaks.
Step 11 - Install the Water Hammer Arrestors
You can now install the water hammer arrestor to your appliances that use water. For the dishwasher, turn the water off at the isolation valve. Twist off the hoses and screw in a hammer arrestor to the valve of the hot and cold water lines. Install a stainless steel braided hose. Use a wrench to tighten the connectors. Turn the water back on.
You are now on your way to saving water and protecting your home’s plumbing from damage.