Mercer Valve Pressure Relief Valve 95-80R15034

Warning: This inspection requires trained personnel with PPE!

Set pressure of the valve verified?

Enter the leak test pressure (90% of the set pressure or 5 psi below the set pressure, whichever is greater)

Contact Mercer Valve for proper leak pressure and specification for the valve if the valve has a CDTP.

Pressure held steady for a length of time without any leakage?

Choose the method used for testing leakage.

Did the valve pass the leak 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?

Visual inspection: Is the PRV correct for the application?

Visual inspection: Are there any apparent problems with the PRV?

Is the nameplate information correct?

Is there any damage to the valve?

Warning: Ensure the valve is not pressurized before starting the inspection

Cap and Seal Wire in good condition

Flanged Connections in good condition

Outlet free of corrosion or debris

External Surface free of damage

Valve Tag information corresponds to service conditions

Two tags present on 9500 Series valves

If the valve fails any of the above checks, do not proceed with set pressure inspection and leak inspection

Sign off on the visual inspection

Warning: This procedure requires trained personnel!

Are two pressure gauges available for testing?

If not, report to the maintenance team and stop the procedure

Enter the reading of the first pressure gauge

Enter the reading of the second pressure gauge

Are the gauge readings identical within their respective tolerances?

If not, both gauges need to be checked for calibration

Does the test gauge have at least 0.25% accuracy over their full scale?

Is the portion of the gauge used more stringent than the set pressure’s tolerance?

- 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.