Mercer Valve Pressure Relief Valve 91-12E31PA7N7

Warning: This procedure requires trained personnel with PPE!

Valves removed from the units and brought to the shop

Valve completely tested and inspected in the shop

Volume of pressure during testing

Pressure losses to the gauges during testing

Supply line pressure during testing

Proper assembly of a test bench

Note: The main disadvantage in offsite testing is time

Warning: This procedure requires trained personnel with PPE!

Is the valve accessible for testing?

If the valve is not accessible, report the issue to the maintenance team and stop the procedure

Are the block valves in place for set pressure testing?

Enter the volume under the valve

Warning: A heavy warn or simmer can cause false readings as a result of insufficient test volume

Is the gauge placement correct for accurate pressure reading?

Enter the pressure reading from the gauge

Warning: If the gauge is placed too far away from the valve or the line has too many restrictions, there will be pressure loss

Warning: This inspection requires trained personnel with PPE!

Seat inspected for cuts and abrasions?

Seat polished and restored if minor scratches or abrasions are present?

Seat replaced if damaged with deep abrasions and cuts?

Enter the diameter, Ds, of the nozzle

Spherical surface portion that engages the seat is clean and smooth?

Spherical surface polished with a fine grade abrasive if minor imperfections exist?

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 3% for valves set 70 psi and above, and 2 psi for valves set below 70 psi.

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: 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?