NZ/NZ-M and NZOS/NZOS-M Series
9
Be sure to slowly introduce pressure into the system to prevent downstream overpressure due to potential rapid
pressure increase. Pressure gauges should always be used to monitor downstream pressure during Startup.
Procedures used in putting this regulator into operation must be planned accordingly if the downstream system is
pressurized by another regulator or by a manual bypass.
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 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 JP Series
pilots, loosen locknut 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 set point adjustment is completed and verified,
tighten the locknut to lock the adjusting screw in position. If the outlet pressure is adjusted by the remote pressure loaded
pilot, the pressure should be slowly loaded or released to the spring cover. Remote loading pressure does not exceed 10 bar.
Adjusting the monitor regulator (Figures 3 and 4) is the same as adjusting the main regulator. Monitor set points 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.
JP Series Pilot Restrictor Screw Adjustment
Note: The Type JPHOM/JPLOM/JPHCM/JPLCM (upstream monitor pilot in working monitor installations) does not have a
restrictor screw.
The restrictor on the pilot controls the regulator’s proportional band droop and speed of response. The restrictor on the pilot
should be adjusted carefully. The restrictor is normally set at the tightest mode till it can no longer be screwed in the clockwise
direction. Observe extreme caution during unscrewing the restrictor so that it does not come out of the pilot body face. In the
event of hunting of the stable outlet pressure, unscrew the restrictor slowly in increment of 1/4 turn until pressure stabilizes,
two turns at most.
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. Introduce upstream pressure by slowly opening inlet valve.
4. Crack open the outlet block valve or bypass valve to allow minimum flow.
5. For a single regulator (Figures 1 and 2), set the pilot to the desired outlet (control) pressure according to the Pilot
Adjustment procedure.
Pre-startup Considerations
Each regulator is factory-set for the outlet pressure specified on the order. If no setting was specified, outlet pressure was
factory-set at the mid-range of the pilot control spring. Before beginning the start-up procedure in this section, make sure the
following conditions are in effect:
• Block valves isolate the regulator
• Vent valves are closed
• A bypass, if any, is in operation
In all cases, check the pilot control spring setting to make sure it is correct for the application.
5.
Startup and Adjustment
CAUTION
1. Follow the procedure in the All Installations section, and then continue with step 2 of this section. The sense line of the
upstream monitor pilot and the bleed and sense lines of the downstream pilot will be connected to the downstream
piping (see Figures 5 and 6).
2. Connect the pilot supply line “S” port for the downstream regulator to the upstream pipe.
3. Connect a sense line from the “BW” port of the upstream working JP Series pilot to the intermediate pressure portion of
piping, using 8 mm or larger outside diameter tubing.
4. Connect a sense line from the “CM” port of the upstream monitor JP Series pilot to the intermediate pressure portion of
piping, using 8 mm or larger outside diameter tubing.
5. Connect a sense line from the upper casing of monitor main valve to intermediate pressure portion, using 10 mm or
large outside diameter tubing (for NZ and NZOS Series 1”, outside diameter of tubing must be at least 14 mm, and inside
diameter not less than 11 mm).