To adjust a water pressure regulator, follow these steps:

1. Locate the water pressure regulator, typically found where the main water line enters the building, often just downstream of the main shutoff valve.
2. Check the current water pressure using a pressure gauge; typical residential water pressure should be between 40 and 60 psi.
3. Loosen the locknut on the adjustment knob or screw using an adjustable wrench or pliers.
4. Turn the adjustment knob or screw clockwise to increase the water pressure or counterclockwise to decrease it. Make small adjustments gradually, as even slight turns affect pressure.
5. After adjusting, restore the water supply and recheck the pressure with the gauge. Repeat adjustments if necessary.
6. Once the desired pressure is set, tighten the locknut to secure the adjustment.
7. Finally, test water fixtures for proper operation and check for leaks around the regulator and fittings.

This process ensures optimal water pressure, protects plumbing fixtures, and prevents water damage due to high pressure.