Pilot Set Pressure Field Test Procedure - Emerson Anderson Greenwood 500 Series Installation And Maintenance Instructions Manual

ANDERSON GREENWOOD SERIES 500 PILOT OPERATED SAFETY RELIEF VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
6 PILOT SET PRESSURE FIELD TEST
PROCEDURE
NOTE
EXTREME CAUTION and appropriate safety
procedures should always be utilized when testing or
servicing a safety relief valve. Any compressible fluid
under pressure is dangerous.
6.1 General
The pilot set pressure on a valve set for
modulating action is best determined when the
main valve dome pressure is measured. From
the discussion in Section 4 Pilot adjustment, set
pressure is defined as that process pressure
where the dome pressure is 70% of the supply
pressure. Typically, this measurement can
not be made since access for measuring this
pressure is not available without depressurizing
the dome and installing special fittings.
FIGURE 5
External sensitivity adjustment
¼" O.D. X .028 wall tube
.10
Ported blind flange
Alternatively, the pilot set pressure can be
checked in the field if the valve is equipped
with a field test accessory with an actuation
indicator. An external test pressure is applied
through the field test valve as shown in
Figure 6. Set pressure is the pressure when the
actuator indicator button retracts, or moves in.
NOTE
Use extreme caution when testing to prevent injury
should the main valve open and discharge product
on personnel. If the main valve must remain closed,
temporarily replace the pilot exhaust vent with an
orifice plug having an orifice diameter of .040"/.060".
This orifice must be removed on completion of field
testing as it prevents the main valve from opening.
Inlet pressure
Supply
11