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Type PS/79-1 and PS/79-2
In addition:
o . Once lever (key 36) and stem (key 12) have been
mounted, check that, with stem (key 12) against
body (key 19), clearance between forked stem
(key 31) and register (A) of lever (key 36) is 0 .2 to
0 .3 mm If not, use register to correct .
▲
The above clearance can be checked by
gently pulling the stem (key 12) upward.
Use the proper tool to make sure that
support of diaphragm (key 9) on the
stem (key 12) is on the same plane as
that supporting the diaphragm (key 9) in
the body (key 19).
p . Mount diaphragm (key 9) and screw on plate
(key 8), first by hand then with box wrench, always
keep diaphragm (key 9) firmly in place to avoid
damage to stem (key 12) and underlying levers .
q . Holding plate (key 8) firmly in place with box
wrench, tighten nut (key 7) .
r . Before remounting cover (key 6), center
diaphragm as follows: mark a reference point
(with pencil) on the diaphragm; turn it to the right
without forcing and mark another reference on
body . Now turn diaphragm to the left and mark a
Troubleshooting
SYMPTOMS
Desired set point is not reached
Outlet pressure drops well below set point
Outlet pressure increases over set point
Slow response to changes in gas demand
Overly rapid response to changes in gas
demand, i .e . Hunting
Gas continually escaping from relief (S)
4
4
CAUTION
Table 2. Troubleshooting for Type PS/79-1, PS/79-2, RE/79-1, and RE/79-2 Pilots
Calibration spring (key 5) is too weak
Filter (key 41) is clogged preventing proper
Pad holder (key 45) is swollen preventing
Pad holder (key 29) is swollen preventing
Faulty sealing of pad holder (key 45)
Faulty sealing of pad holder (key 29)
Insufficient flow rate of valve seat (key 25)
(only for Types PS/79-1 and PS/79-2)
Excessive flow rate of valve seat (key 25)
(only for Types PS/79-1 and PS/79-2)
(only for Types PS/79-1 and PS/79-2)
further reference . Position the diaphragm mark
midway between the two marks on the body .
s . Tighten all screws uniformly to ensure
proper sealing .
The pilot has a wide range of self-
adjustment values. However, given
actual operating conditions, it may be
necessary to assist it at times by finding
the best setting of pin screw/register
(key 24) or the most suitable calibration
orifice (key 18).
Spare Parts
Spare parts storage shall be done by proper
procedures according to national standard/rules to
avoid over aging of rubber parts or any damage to
critical parts .
Waste Disposal Requirements
The disposal of waste and e-waste from packaging,
spare parts, lubricants, whole equipment/systems
and produced in occasion of on-site surveillance
activities (during service life and/or at the end of
their service life), shall be carried out in accordance
with the requirements of applicable local regulation
(laws and rules) .
CAUSE
Leaks from pilot connections
through-flow of gas
proper feed flow
proper feed flow
Over large calibration jet (key 18)
Calibration jet (key 18) is too small
Incorrect internal parts assembly
Defective seal of pad (key 59)
▲
CAUTION
ACTIONS
Check the springs catalog and replace it with a stronger one
Check pilot feed connections and proper gas flow feeding
Clean or replace filter
Replace pad holder
Replace pad holder
Replace pad holder
Replace pad holder
Increase flow by means of register/pin screw (key 24)
Replace calibration jet with a smaller one
Reduce flow by means of a pin screw (key 24)
Replace calibration jet with a larger one
Check clearance between lever (key 36) and valve seat (key 25)
Replace pad
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