Mercer Valve Pressure Relief Valve 91-12F41BA7B5

Warning: This inspection requires trained personnel with PPE!

Set pressure of the valve verified?

Enter the set pressure of the valve

Contact Mercer Valve Co., Inc. 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

Zero bubbles observed for one minute in API 527 test?

Warning: This inspection requires trained personnel with PPE!

The set pressure inspection is performed in accordance with the ASME BPVC.

The set pressure tolerance is calculated based on the actual nameplate set pressure.

The set pressure test should be performed before and after any repairs.

The set pressure is inspected to the definition listed in NB-18.

The correct fluid for testing has to be used to achieve accurate results.

Setting procedures should be in accordance with ASME PTC 25.

The rate of the system pressure increase should be slow when the pressure is within 15% of the set pressure.

The procedures for testing set pressure are as follows.

Warning: Only trained personnel should perform this procedure

Valve removed from the application

Thorough inspection of the valve performed

Is transporting the valve necessary?

Select the type of mobile test unit used

Document the limitations of the test stand

Enter the pressure the test stand is designed for

Seat inspected for cuts and abrasions

Seat polished and restored if minor scratches or abrasions are present

Seat replaced if deep abrasions and cuts are present

Diameter, Ds, of the nozzle measured

Spherical surface portion that engages the seat is clean and smooth

Disk replaced if the spherical surface is damaged or scratched

For dependable performance, PRVs must be maintained regularly.

Mercer Valve Co., Inc. recommends its PRVs are inspected and tested annually.; After the valve has been in installed and a service history has been established, the testing and inspection frequency may be adjusted.

Some guidelines for testing frequencies are found in NB-23, API 576, and API 598.; Additionally, government jurisdiction should be reviewed.; When maintenance is done, qualified repair personnel should perform it.; Qualified repair personnel conducting the annual inspection and testing may alter the maintenance schedule based on the service conditions.

During the inspection, a visual inspection, a set pressure verification, and a leak check should be completed.; These tests can be performed while the PRV is installed on its system or when it’s on a testing bench.; The PRV can only be tested while on its application if there is a method and procedure to apply a controlled pressure to the PRV’s inlet without exceeding any limits of the system.

A visual inspection is used to identify if the PRV is installed properly, is correct for the application, and doesn’t have apparent problems.

Check the nameplate information to verify that the valve is installed on the proper service. A missing nameplate requires immediate addressing.

If the valve is installed on gas/vapor service, the nameplate’s capacity will indicate an air capacity at standard conditions.

If the valve is on liquid service, the nameplate will indicate a water capacity.

Check the seal wire. A broken seal wire indicates that an unqualified person has adjusted the set pressure this also removes any warranty the valve had.