Mercer Valve Pressure Relief Valve 95-85S16021

- Pressure Relief Valve In Situ Testing

Testing and inspecting in place eliminates the laborious task of removing and handling the valve.

This is especially desirable with large PRVs.

Additionally, not disturbing the existing connections reduces the chance of compromising the existing seals.

This type of testing is very useful when a system cannot be shut down for long lengths of time.

There are disadvantages to this type of testing.

The inspection process is more difficult because the accessibility of the valve is reduced.

The outlet pipe is often still attached and the internal parts are not observable for the visual inspection.

This can also make it difficult to leak check.

Warning: This procedure requires trained personnel with PPE!

Upload a photo of the lift checking apparatus

Enter the measurement of the movement of the disk from the closed position to the mechanical stops at the fully open position

Enter the minimum lift for certified PRVs as found in the NB-18 publication

Does the lift meet the minimum requirement?

Warning: This inspection requires trained personnel with PPE!

Set pressure of the valve verified?

Note: Leak test pressure should be 90% of the set pressure or 5 psi (34.5 kPa) below the set pressure, whichever is greater.

If the valve has a CDTP, the leak test pressure will be below the CDTP in lieu of the set pressure.

Contact Mercer Valve for proper leak pressure and specification for the valve.

Pressure held steady during the test?

Any leakage observed during the test?

Select the method used for testing leakage

9500 Series valves tags inspection

Issues found during the inspection

Sign off on the visual inspection

Warning: Only qualified repair personnel should perform this maintenance.

Is there pressure within the main valve or pilot valve?

If there is pressure, remove it before servicing.

Visual inspection: Is the PRV installed properly and correct for the application?

Visual inspection: Any apparent problems with the PRV?

Nameplate check: Is the valve installed on the proper service?

Seal wire check: Is the seal wire broken?

Damage inspection: Any damage to the valve?

Flow inspection: Any issues that would keep the valve from opening or inhibit flow?