Pressure reducing valves, like most components in your system, are subject to water quality and repetitive use. They should be inspected and cleaned at least once every 12 months.
Replacement cartridges are availabe if needed to avoid replacing the entire valve, but usually simple maintenance will keep the valve operating trouble-free. It is important to understand that the pressure reducing valve's cartridge contains a diaphragm, strainer, seat, valve plug and compensating piston. It is pre-assembled as a self-contained unit with a cover and can be removed for inspection and maintenance. Maintenance instructions can also be found in the installation instructions provided with the product.
When checking, cleaning or replacing the cartridge, simply follow these steps:
1) Shut off the inlet and outlet isolation valves.
2) The downstream pressure setting can be left at the set value.
3) Remove the upper cover, using a spanner. This cover is integral with the cartridge.
4) Check and clean the filter and seat.
See how Lee's Plumbing is using pressure reducing valves in Logan, Utah in this case study.