Mercer Valve Pressure Relief Valve 81-12151B18G21

The following general procedure is recommended for the disassembling of a Mercer 8100 Series PRV.; Non-standard, “special”, configurations are possible and these instructions may not be reflective of them; a special configuration is indicated by a special code at the end of the PRV’s part number.; Always make sure there is no pressure in the system prior to removing a PRV.

These instructions are divided into two sections: 1” Body and 2” Body.

1. Cut and remove the seal wire and unscrew the cap to expose the adjustment screw.

i) Go to "c" if the valve is a lift lever configuration.

2. Loosen the lock nut from the adjustment screw.

3. Relieve the compression on the spring by turning the adjustment screw counter clockwise.; This is important so that components will not spring out and pose a hazard.; If the adjustment screw begins to appear as residing back into the bonnet during the relieving of the preload, then the spring compression has been completely removed and the adjustment bushing is beginning to re-compress the spring.

4. Rigidly support the body to prevent movement during disassembly.

5. Unscrew the inlet base using the appropriate wrenching flats.; 6. Remove the set spring and discard the disk subassembly.

Warning: This procedure requires trained personnel with PPE!

Enter the pressure losses to the gauges

Warning: This inspection requires trained personnel with PPE!

Enter the set pressure of the valve

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

Did the pressure hold steady during the test?

If the pressure did not hold steady, there is a potential leak and the valve should be removed for further testing

Upload a photo of the valve after removal

Enter the pressure in the secondary pressure zone

Warning: This maintenance check requires qualified repair personnel!

Is the PRV correct for the application?

Are there any apparent problems with the PRV?

Is the nameplate information correct?

Is there any damage to the valve?

Are there any issues that would keep the valve from opening or inhibit flow?

Are there any problems found during the visual inspection?

Warning: This procedure requires trained personnel!

Are two pressure gauges used for testing?

Are the gauges reading identical values within their respective tolerances?

Select the type of the first gauge

Select the type of the second gauge

Is the analog (dial) gauge not liquid filled?

Does the digital gauge respond to quick pressure increases?

Enter the accuracy of the test gauges (in %)

Is the selected portion of the gauge more stringent than the set pressure's tolerance?