Household Water Pressure Regulators
Questions and Answers

Q: What is the function of a water pressure regulator?

A: A household water pressure regulator reduces the water pressure from the public water main to a pressure that is usable by the customer and compatible with normal household plumbing and fixtures. It also prevents pressure surges from entering the household plumbing from the public main. High water pressure can result in dripping faucets and water pipes, and it can damage appliances.

Q: How does a pressure regulator work?

A: A pressure regulator is a spring-loaded valve that regulates pressure on the downstream (house) side of the valve. Altering the degree of spring compression changes the downstream pressure.

Q: Who is responsible for installing and maintaining the pressure regulator?

A: The property owner is responsible for installing and maintaining the pressure regulator.

Q: Where should the pressure regulator be installed?

A: On new installations, the pressure regulator is usually installed downstream, (on the house side) of the water meter, near the house.

Q: How do I know if the pressure regulator is working?

A: There are a few ways to ensure proper regulator operation. One option is installing a gauge on both sides of the regulator. If the upstream reads higher than the downstream house side gauge, then the regulator is working properly. If there are no gauges, you might notice symptoms of pressure malfunction, which include “clanging” or “rattling” of pipes when plumbing fixtures are in use.

Q: Can I adjust and repair my pressure regulator?

A: Yes. A homeowner or plumber can accomplish this by consulting the pressure regulator manufacturer’s instructions. The adjustment mechanism is usually a screw on top of the regulator. Turning this screw changes the degree of spring compression. Generally, turning the screw clockwise increases house water pressure and turning the screw counter-clockwise reduces house pressure. Repair kits for rebuilding pressure regulators are usually available from the manufacturer. The assistance of a licensed plumber for pressure regulator installation and maintenance is recommended.

Q: To what pressure should I adjust my pressure regulator?

A: Most homeowners set their pressure at approximately 50 pounds per square inch (psi), but it’s mostly a matter of owner preference. However, lower settings will help conserve water and the life of plumbing fixtures.

Q: Are pressure regulators required?

A: Yes, Section 608.2 Excessive Water Pressure of the Uniform Plumbing Code requires pressure regulators with a strainer whenever the static water pressure from the supply piping exceeds 80 psi. They are especially valuable in controlling surges that may occur in the public supply.

Q: Are pressure regulators necessary if the pressure at the public main is naturally low or moderate?

A: Yes. There are a couple of reasons: 1.) Most public water mains are supplied by pumps or pressure-reducing valves. This equipment may produce temporary high pressure surges, which can be transmitted to household plumbing. A properly operating household pressure regulator will help prevent these surges from entering your plumbing. 2.) Your water provider may increase the pressure in the main that supplies your house.

What is the static water pressure at my property? 

A rough estimate of your static water pressure can by determined with a few short steps. Contact the Engineering Department to determine which pressure zone feeds the property. Calculate the approximate static pressure by subtracting the site elevation from the hydraulic grade line (tank elevation) of the appropriate pressure zone, and then multiply the difference by 0.433. The Engineering staff can help you determine the static water pressure by calling with the location of the property (street address or Assessor's Parcel Number).

It is the District’s policy that the allowable static pressure range at the water meter is 40 psi to 175 psi. A pressure regulator is required to be installed on the District’s side of the meter if water pressure exceeds 175 psi. A pressure regulator may be needed on the customer’s side of the meter, at the property owner’s expense, to achieve the desired pressure on site. The District’s pressure regulator is in place to protect the water meter. It is not in place to protect the customer’s service line or property.