Pressure-reducing valve station annual maintenance checklist

Owner and occupants warned before downstream pressure is disturbed

Owner, occupants and any pressure-sensitive process users told when the zone may see low or swinging pressure, and the work timed away from peak draw.

Arrival pressures recorded before any adjustment

Inlet, flowing and no-flow reduced-side pressures read and photographed before anything is touched, so the as-left figures compare to where the valve really was.

Station gauges checked against a calibrated test gauge

Each station gauge compared with a calibrated test gauge at the same tap, and any gauge outside its stated accuracy replaced before setpoints are trimmed.

Relief valve exercised and reseats clean

Reduced-side relief lifted, flows and reseats without weeping, discharge line clear and terminated correctly.

Bypass valve stroked and holds

Bypass fully opened and closed, no seizing, seat holds tight when closed so it isn't feeding around the PRV.

Relief setting on its tag checked above the PRV setpoint

Where the station has a relief valve, its tag shows a set pressure above the PRV setpoint and within the downstream design limit, as the drawings or engineer set it.

Valve isolated, tagged and bled to zero before it is opened

Inlet and outlet shut and tagged under the site's procedure, the zone carried by a parallel valve, an attended bypass or an agreed shutdown, and the gauge at zero first.

Strainer screen pulled and cleaned with the station isolated

Deeper than the quarterly blow-down: screen removed, cleaned and checked for tears or collapse, cap gasket inspected and the cap reseated.

Diaphragm, disc and seals renewed on the manufacturer's schedule

Soft parts replaced where the manufacturer's rebuild interval or the wear found calls for it, and the kit and parts used recorded against the valve.

Valve closed up and repressurized slowly before setting

Bonnet bolts torqued to the manufacturer's value, tags removed by whoever hung them, isolation valves reopened slowly, air vented downstream and every opened joint dry.

Each PRV checked for seat wear and adjusted to setpoint

Valve exercised, seat and diaphragm condition checked where accessible, downstream pressure trimmed back to the intended setpoint and confirmed stable.

Lead-lag setpoints staged so both valves share load

On parallel PRVs the lag valve set below the lead so it opens on higher demand, each confirmed carrying flow rather than one doing all the work.

Each staged valve proven to hold the zone alone

On parallel or staged sets, each valve isolated in turn while the other holds the zone at setpoint, so either can carry it during the other's rebuild.

Owner told the zone is back at normal pressure

Inlet and outlet open, bypass shut, and the owner or building manager told the zone is restored, with what was found and replaced.

As-left pressures and gauge swaps filed as the new baseline

As-left setpoints, the relief setting and any gauge replacements written to the station record, so next year's service reads against them.