Types 1098-EGR and 1098H-EGR
12
On a working monitor installation (Figure 7), be sure
that the second-stage working regulator is set to
operate at a pressure lower than the Type 1098-EGR
or 1098H-EGR working monitor regulator. To do this,
increase the setting of the monitoring pilot until the
working pilot is in control of the intermediate pressure
and the second-stage working regulator is in control
of the downstream pressure. If this is not done,
the monitoring pilot tries to take control of the
downstream pressure.
1. Slowly open the upstream block valve and
the hand valves in both pilot supply lines. This
energizes both pilots so that their setpoints can
be adjusted. Partially open the downstream block
valve for minimum ow.
2. To enable intermediate pressure adjustment with
the working monitor regulator, slowly open the
hand valve in the intermediate pressure control line.
3. To enable downstream pressure adjustment with
the second-stage working regulator, slowly open
the hand valve in the control line to this regulator.
4. Adjust the setting of the monitoring pilot to
establish the desired emergency downstream
pressure, which is to be maintained in the event
of open failure of the second-stage working
regulator. The emergency downstream pressure
should exceed the desired downstream pressure
by at least the amount listed in Table 7. The steps
followed to set the monitoring pilot may vary with
each piping situation; however, the basic method
remains the same. The following sub steps a
and b may be used as examples for setting the
monitoring pilot:
a. Increase the outlet pressure setting of the
second-stage working regulator until the
monitoring pilot takes control of the downstream
pressure. Adjust the monitoring pilot setting
until the desired emergency downstream
pressure is achieved. Then, readjust the second-
stage working regulator to establish the desired
downstream pressure.
b. Install special piping (not shown in
Figure 7) so that the monitoring pilot senses
the intermediate pressure. The intermediate
pressure then appears to the monitoring pilot as
if it were increased downstream pressure,
and the monitoring pilot controls and reduces
the intermediate pressure. Adjust the monitoring
pilot setting until the desired emergency
downstream pressure is achieved at the
intermediate pressure stage. Then slowly
close the special piping, and open up the
monitoring downstream control line for
normal service.
Figure 7. Typical Working Monitor Installation
26A4298-A
A2118-2
UPSTREAM
PRESSURE
VENT VALVE
UPSTREAM
BLOCK VALVE
HAND VALVE
TYPE 161AYW OR 627-109
MONITORING PILOT
TYPE 1098-EGR
OR 1098H-EGR
WORKING
MONITOR
REGULATOR
HAND
VALVE
VENT
VALVE
STANDARD 6350 SERIES PILOT FOR
TYPE 1098-EGR OR 1098H-EGR REGULATOR
SECOND STAGE
REGULATOR
HAND VALVE
VENT VALVE
DOWNSTREAM
BLOCK VALVE
DOWNSTREAM
PRESSURE
HAND VALVE
INTERMEDIATE
PRESSURE
VENT VALVE
WORKING MONITOR
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