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LOADING REGULATOR
MAIN VALVE PLUG
36A1546-B
A2947
INLET PRESSURE
LOADING PRESSURE
DOWNSTREAM PRESSURE
Figure 7. Operational Schematic of Pressure-Loaded
Type 92C Regulator
4. Tighten the Type 6392 pilot of the upstream valve
all the way in to its highest spring setting.
5. Tighten the Type 6392 pilot of the downstream
valve to the desired downstream pressure.
6*. Loosen the Type 6392 intermediate pilot on
the upstream valve to the desired intermediate
pressure (normally 50% of inlet pressure).
7. Loosen the Type 6492HM (or 6492HTM) safety
override pilot of the upstream valve until there is no
spring load.
8. Tighten the Type 6392 pilot of the downstream
valve all the way in to its highest spring setting.
9. Tighten the Type 6492HM (or 6492HTM) safety
override pilot of the upstream valve to desired
pressure as specified per ASME Boiler and
Pressure Vessel Code, section VIII.
10.* Loosen the Type 6392 pilot of the
downstream valve to the desired downstream
pressure setpoint.
*Fisher™ recommends establishing setpoint by tightening the adjusting screw.
BLEED RESTRICTION
OPTIONAL
PIPING
FOR STEAM
LOADING
MAIN VALVE
DIAPHRAGM
PITOT TUBE
MAIN VALVE SPRING
Shutdown
To take the regulator out of operation:
1. If a bypass line is used, slowly open the
bypass line block valve while monitoring the
downstream pressure.
2. Close the upstream block valve.
3. For a pilot-operated regulator, close the
downstream block valve.
For a pressure-loaded regulator, close the
shutoff valve in the pressure-loading piping
or tubing.
4. Close the control line shutoff valve.
5. Vent the regulator, the control line and the pilot
supply line to release any trapped pressure.
Maintenance
Regulator parts are subject to normal wear and must be
inspected periodically and replaced as necessary. The
frequency of inspection and replacement depends upon
the severity of service conditions and upon applicable
Federal, state and local codes and regulations.
▲
WARNING
Avoid personal injury or property damage
from sudden release of pressure or
uncontrolled steam or other process
fluid. Before starting disassembly:
• Isolate the regulator from the process,
• Release process pressure, and
• Vent the pilot supply and main valve
loading pressures.
This section contains separate procedures for regulator
and pilot maintenance.
Type 92C Regulator
Perform these procedures when replacing diaphragm,
the stem assembly, the valve plug or the orifice. Refer
to the correct section for the required instructions. Key
numbers refer to Figure 8 unless otherwise indicated.
The regulator may remain in the pipeline during
maintenance procedures unless the valve body is to
be replaced or removed for repairs. For pilot-operated
regulators, the pilot may remain on the pipe nipple
(key 23, Figure 10) unless the pilot body (key 1,
Figure 9) is to be removed or the entire pilot replaced
as a unit.
Type 92C
9
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