Grain Systems PNEG-526 - Manual (Page 170)

To Change Spring
A. The outlet pressure ranges of spring 9 are given in the tables
on Pages 3 and 4. To change the spring:
1. Remove top cap 1.
2. Unscrew and remove adjustment button 3, 3a or 6 by turn-
ing counterclockwise, and remove spring 9.
3. Insert new spring. Make sure it is positioned correctly at the
bottom before replacing adjustment button 3, 3a or 6.
4. Adjust for the desired outlet pressure per previous section
“Set Point Adjustment”.
5. When adjustment is complete, replace top cap 1. Screw it
securely into place. Leaving it off could result in unstable
regulator operation.
6. New spring range should be marked on regulator. If old spring
range appears on regulator, it should be removed.
Shutdown
A. To take the regulator out of service, close the inlet stop valve
first. Close it carefully. Then close the outlet stop valve.
Before working on regulator, read the next section “General
Servicing Instructions” and the applicable servicing instructions.
Set Point Adjustment
A. The 121 is factory adjusted as specified on the order. To change
the set-point, readjust as follows:
1. Remove the top cap 1.
2. Adjust set-point with adjustment button 3, 3a or 6. Turn clock-
wise to increase and counterclockwise to decrease the
outlet pressure.
NOTE: a. Only make this adjustment when gas is actually
flowing through the regulator. The flow should be
small (approximately 1000 SCFH). Do not adjust
when the regulator is closed and there is no flow.
b. Do not increase the set-point beyond the upper
limit of the outlet pressure range for the spring 9
(refer to spring tables, Page 3).
c. Always check the outlet pressure with a pressure
gauge while adjusting the set-point.
3. When adjustment is complete, replace top cap 1. Screw it
securely into place. Leaving it off could cause unstable regu-
lator operation.
CAUTION
It is the user’s responsibility to assure that all
regulator vents and/or vent lines exhaust to a
non-hazardous location away from any po-
tential sources of ignition. Where vent lines
are used, it is the user’s responsibility to as-
sure that each regulator is individually vented
and that common vent lines are not used.
CAUTION
The diaphragm case vent must be positioned
to protect against flooding, drain water, ice
formation, traffic, tampering, etc. The vent
must be protected against nest building
animals, bees, insects, etc. to minimize the
chances for foreign material from collecting
in the vent side of the regulator diaphragm.
General Servicing Instructions
A. Before any disassembly of the regulator make sure it is com-
pletely depressured. Pressure must be fully released from the
inlet, the outlet and the control line connection. Failure to ad-
equately depressure could result in serious personal injury.
B. Carefully note the location and position of all disassembled
parts to be certain reassembly is correct. Inspect each part
carefully and replace any that are worn or damaged or other-
wise unsatisfactory.
C. Upon completion of servicing, make certain that the regulator
installation is entirely free of leaks.
CAUTION
Turn gas on very slowly. If an outlet stop valve is
used, it should be opened first. Do not overload
diaphragm with a sudden surge of inlet pressure.
Monitor the outlet pressure during start-up to
prevent an outlet pressure overload.
CAUTION
Regulators are pressure control devices with
numerous moving parts subject to wear that
are dependent upon particular operating
conditions. To assure continuous satisfactory
operation, a periodic inspection schedule
must be adhered to with the frequency of
inspection determined by the severity of
service and applicable laws and regulations.
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