Mercer Valve Pressure Relief Valve 95-90T17093

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: This procedure requires trained personnel!

Are two pressure gauges used for testing?

Are the gauges reading identical values within their respective tolerances?

If the gauges are not reading identical values, both should 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?

For analog gauges, is only the middle 1/3 or less of the gauge used?

Is each gauge calibrated using a dead weight tester?

Sign off on the monthly gauge calibration

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 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 per NB-18 publication

Does the lift meet the minimum requirement?

Sign off on the pressure relief valve lift check

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 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