16 | Baker Hughes
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Pilot Disassembly
(Figure 16 from pilot IOM)
1. After depressurizing the pilot and main valve unscrew and
remove Body Insert Assembly.
2. Remove the Stem O-ring from the pilot body using a suitable
tool and being careful not to scratch the O-ring Groove.
Figure 16
A paper clip easily extracts the O-Ring out of the pilot body.
Note: A spare Body Insert Assembly may be installed and
the main valve returned to service if time is a factor. Make
sure the Stem O-Ring is in place in the Pilot Body before
installing the new Body Insert Assembly or, if removed, slip
a new O-Ring over the Stem of the Body Insert Assembly
prior to installing it in the Pilot Body.
3. Remove the Bottom Cap from the Body Insert and remove
the internal parts. The Orifice Assembly can be easily pushed
out of the Insert Body by pushing on the stem coming out at
the top of the Insert Body.
ATTENTION: Do not scratch or damage the O-Ring sealing
surfaces of the Body Insert.
4. Inspect all parts for wear or damage. Replace as necessary.
5. Pilot Diaphragm: Release all Main Spring tension by
unscrewing Adjusting Screw. Remove Closing Cap, Spring
Follower, and Main Spring.
6.
Remove Spring Housing Cap Screws and remove
Diaphragm Assembly.
7. Disassemble Diaphragm Assembly and inspect Diaphragm.
Replace if necessary.
Pilot Assembly
1. Diaphragm Assembly: Install the Pilot Diaphragm with
convex side toward Diaphragm Plate and Main Spring
(Figure 16). Tighten nut on the Diaphragm Retainer to
approximately 5 to 6 ft-lbs (6.78 - 8.14 n-m) torque.
ATTENTION: Overtightening will distort the Pilot Diaphragm.
Note: The high pressure constructions (Series 20H &
20HS) differ from the Series 20 & 20S with the addition of a
diaphragm spacer assembly.
Figure 17
Diaphragm Assembly for the Flowgrid Series 20 & 20S
Pilot.
Figure 18
Insert Body Insert (Cartridge) with lubricated Stem O-Ring
into the Pilot Body.
2. Place Diaphragm Assembly in the pilot body with the
diaphragm touching the grooved sealing surface of the pilot
body. (Figure 13)
Figure 19
Placing Diaphragm Assembly on Pilot Body.
3. Place Spring Housing on Pilot Body with the vent port aligned
with the loading port so that it will face down when the pilot
is mounted on the regulator so that condensation will drain
away instead of accumulating and possibly freezing.
Figure 20
Placing the Spring Housing on the Pilot Body.
4. Install Spring Housing Cap Screws. Use cap screws
supplied and tighten evenly to 10 ft-lbs (13.56 n-m) torque.
5. Install Spring and Spring Follower. Lubricate Spring Follower
with a Petroleum Oil Grease such as Lubriplate No. 1051.
