Type 399A-161-112
15
Working Monitor Installations
1. Follow the procedures in the All Installations sec-
tion, and then continue with step 2 of this section.
2. On working monitor installations, the working
monitor regulator is always upstream and acts as a
first-stage regulator by using the working pilot during
normal operation. This arrangement allows the work-
ing monitor’s performance to be observed at all times.
Then, should the downstream second-stage regulator
fail-open, the upstream working monitor regulator as-
sumes the entire pressure reduction function of the
system through the monitoring pilot taking control of
downstream pressure.
StarStartuptup andand AdjustmentAdjustment
Note
The maximum inlet pressure for a specific
construction is given in table 2. Use pres-
sure gauges to monitor inlet pressure,
outlet pressure, and any intermediate
pressure during startup.
Startup for Both Single-Regulator and
Monitoring Installations
1. All block valves and vent valves (as shown in fig-
ure 3) are closed.
2. Back out the pilot adjusting screw(s).
3. As shown in figure 4, turn the Type 112 restric-
tor(s) to the START position.
4. SLOWLY OPEN the valves shown in figure 3, in
the following order:
a. Pilot supply and control line valve(s) E if used,
b. Inlet block valve A, and
c. Outlet block valve B.
5. Turn the restrictor(s) to RUN position 2.
6. For a single regulator, set the pilot to the de-
sired outlet (control) pressure according to the pilot
adjustment procedure.
7. For a wide-open downstream monitor installa-
tion, adjust the upstream working regulator pilot until
intermediate pressure is equal to inlet pressure. Adjust
the downstream monitoring regulator pilot to the de-
sired monitoring takeover pressure. Reduce the up-
stream working regulator pilot setting to normal control
pressure.
Figure 4. Restrictor Adjustment
W45591/IL
8. For a wide-open upstream monitor installa-
tion, adjust the downstream working pilot wide open.
Adjust the upstream monitoring regulator pilot to the
desired monitor takeover pressure. Reduce the down-
stream working regulator pilot setting to normal control
pressure.
9. For a working monitor installation, set the up-
stream working monitor override pilot adjusting screw
to a safe maximum pressure setting. Adjust the up-
stream working pilot to the desired intermediate pres-
sure setting. Adjust the downstream working regulator
pilot to a pressure setting slightly above the desired
override pressure setting. Adjust the upstream working
monitor override pilot to its desired set point. The set
point of the override pilot should be approximately one
proportional band greater than the downstream sys-
tem pressure (see table 3 for proportional band val-
ues). Finally, establish final desired downstream pres-
sure by adjusting the downstream working regulator
pilot.
Pilot Adjustment
Remove the pilot closing cap (key 16, figures 20 and
21 or key 3, figure 23) and loosen the locknut (for
Type 161, 161M, 161H, 161HM, 161EB, 161EBM,
161EBH, or 161EBHM only, key 12, figures 20 and
21). Turn the adjusting screw (key 11, figures 20 and
21 or key 2, figure 23) into the spring case to increase
the downstream pressure. Turn the adjusting screw
out of the spring case to decrease the downstream
pressure. When the required downstream pressure is
maintained for several minutes, tighten the locknut (for
Type 161, 161M, 161H, 161HM, 161EB, 161EBM,
161EBH, or 161EBHM only) to lock the adjusting
screw in position and replace the pilot closing cap.
Type 112 Restrictor Adjustment
The Type 112 adjustable restrictor (figure 4) controls
regulator proportional band (outlet pressure droop)
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