Startup
1.
Make sure all block valves, vent valves and
control line valve(s) are closed.
2.
Back out the pilot adjusting screw(s).
3.
Slowly open
the valves in the following order:
a. Pilot supply and control line valve(s), if used
b. Inlet block valves
4. Crack open the outlet block valve or bypass valve
to allow minimum flow.
5.
For a single regulator
, set the pilot to the desired
outlet (control) pressure according to the Pilot
Adjustment procedure.
For a single regulator with a Type PRX/131 pilot
,
turn the adjusting screw on the Type PRX/131 all the
way into the spring case. Adjust the Type PRX/120
pilot to the desired setpoint of the Type PRX/131,
which should be 5 to 10 psi / 0.34 to 0.69 bar above
the desired Type PRX/120 control pressure. Adjust the
three-way valve (key 77) to vent-to-atmosphere to be
able to hear when gas starts flowing from the port. Turn
the Type PRX/131 out of the spring case until you hear
audible flow, then return the three-way valve handle to
vent downstream. Then adjust the Type PRX/120 pilot
to the desired outlet (control) pressure according to the
Pilot Adjustment procedure.
For a wide-open downstream monitor installation
,
adjust the upstream working pilot until intermediate
pressure is higher than the desired setpoint of the
monitor pilot. Adjust the downstream monitoring pilot to
the desired monitoring takeover pressure. Reduce the
upstream pilot to the normal outlet pressure setting.
For a wide-open upstream monitor installation
,
adjust the downstream working pilot to a setpoint
higher than the setpoint of the monitor pilot. Adjust the
upstream monitoring pilot to the desired monitoring
takeover pressure. Reduce the downstream pilot to the
normal outlet pressure setting.
For a working monitor installation
, adjust the
setpoint of the upstream monitor pilot to the desired
maximum pressure. Adjust the upstream working pilot
to the desired intermediate pressure setting. Adjust the
downstream pilot to a pressure setting slightly above
the upstream monitor pilot pressure setting. Adjust the
upstream monitor pilot to its desired setpoint. Establish
final desired downstream pressure by adjusting the
downstream working regulator pilot.
For a wide-open monitor installation with a
Type PRX/131 pilot (Figure 3)
, turn the adjusting
screw on the Type PRX/131 all the way into the spring
case. Adjust the Type PRX/120 working pilot to a
setpoint higher than the Type PRX/120 monitor pilot.
Set the Type PRX/120 monitor pilot to the desired
setpoint of the Type PRX/131 pilot, which should be
5 to 10 psi / 0.34 to 0.69 bar above the monitor pilot
setpoint. Adjust the three-way valve (key 77) to vent to
atmosphere to be able to hear when gas starts flowing
from the port. Turn the Type PRX/131 adjusting screw
out of the spring case until you hear audible flow, then
return the three-way valve handle to vent downstream.
Reduce the Type PRX/120 monitor pilot to the desired
monitor takeover pressure. Reduce the Type PRX/120
working pilot to the normal outlet pressure setting.
6. After adjusting the PRX Series pilot(s) to the
desired pressure setting(s), slowly open the
downstream block valve wide open.
7.
Close the bypass valve, if used.
Pilot adjustment
The adjustment of the regulators is performed by
means of the pilot adjustment screw, which varies
the compression of the control spring. Adjustment is
performed while the regulator is in in operation with
the aid of a pressure gauge to monitor downstream
pressure. The shutoff valve downstream of the
regulator must not be completely closed, as it
is necessary that a small quantity of gas flows
downstream to allow the outlet side to vent, when it is
necessary to lower the pressure.
For PRX Series pilot (Figure 10), loosen locknut
(key 2) and turn the adjusting screw into the spring
case (clockwise) to increase and out of the spring
case (counterclockwise) to decrease the downstream
pressure. When the desired setpoint adjustment is
completed and verified, tighten the locknut to lock the
adjusting screw in position.
No adjustment is needed to the Type SA/2 pilot supply
filter regulator.
Adjusting the monitor regulator (Figure 3) is the same
as adjusting the main regulator. Monitor setpoints
are set slightly higher than the main regulator. The
monitor pressure setting should be adjusted so it is at
minimum two times the pilot accuracy band pressure
above the working regulator pressure setting.
PRX Series Pilot Restrictor and Damper
Screw adjustment
note
The Type PRX/125 (upstream monitor
pilot in working monitor installations)
does not have a restrictor screw.
10
Type FL
North America
Only
