Emerson Fisher 1098-EGR Instruction Manual page 11

A6788
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
LOADING PRESSURE
INTERMEDIATE PRESSURE
Startup
On a working monitor installation (Figure 6), 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 flow.
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
Types 1098-EGR and 1098H-EGR
TYPE Y600M OR 627-109
MONITORING PILOT
6350 SERIES PILOT
TYPE Y600M OR 627-109
MONITORING PILOT
Figure 6. Typical Working Monitor Installation
6350 SERIES PILOT
6350 SERIES PILOT
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 6) so
that the monitoring pilot senses the intermediate
pressure. The intermediate pressure then
appears to the monitoring pilot as if it was
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.
5. Slowly open the downstream block valve.
6. Slowly close the bypass valve, if any.
6350 SERIES PILOT
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