10 | Baker Hughes
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10. PILOT GAS HEATERS (OPTIONAL):
Pilot supply gas can
be heated to prevent the formation of ice or hydrates in the
pilot system. Pilot supply gas heaters should be connected
after the pilot filter (if one is used).
11. CONTROL LINES:
The user will need to install a
DOWNSTREAM SENSE line (CONTROL LINE) from
the back port on the actuator to a location at least 8-10
pipe diameters downstream (see Figure 6). Since there
is flow in the DOWNSTREAM SENSE line, ½” tubing is
recommended
NOTE: The control line connection should be 8-10 pipe
diameters away from areas of turbulence (such as valves,
reducers, and elbows) and should have a full opening into
the pipe, free from burrs, drill peels, and weld slag. Shutoff
valves are not required in the control line(s), but if installed,
they should be of the full opening type. The control line
connection should be in a section of pipe where the gas
velocity is less than 100 ft/s (30 m/s) for stability.
12. VENT VALVES AND GAUGE CONNECTIONS:
Troubleshooting recommendation. To aid in maintenance
and Troubleshooting, shut off and vent valves can be
installed in tubing connections, and should be of the full
open or ball style.
Maintenance
Pilot parts are subject to normal wear and must be inspected
and replaced as necessary. The frequency of inspection and
replacement of parts depends on severity of service conditions
and/or the requirements of local, state, and federal regulations.
Be certain that the name plates are updated to accurately
indicate any field changes in equipment, materials, service
conditions, or pressure settings.
NOTE: Before disassembly make sure the regulator and
pilot have been isolated from the process by closing block
valves on the inlet and outlet sides of the regulator. Safely
release pressure and process fluid from the regulator body
and pilot system. Failure to properly complete these steps
may result in personal injury and property damage.
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.
NOTE: A spare Body Insert assembly may be installed and
the regulator 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. Be sure to lube the
new stem O-Ring prior to installation.
Pilot Disassembly - All Series 22 pilots
3.
Remove the Bottom Cap from the Body Insert and remove
the internal parts. The Orifice Assembly can be easily pushed
out of the Body Insert using a heavy paper clip or 0.045”
(1.14mm) diameter wire. See Figure 9.
NOTE: Do not scratch or damage the O-Ring sealing
surface of the Body lnsert.
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. Remove Spring Housing Cap
Screws and remove Diaphragm Assembly & Disassemble
Diaphragm Assembly and inspect Diaphragm. Replace if
necessary.
Pilot Assembly - Series 22
1.
Diaphragm Assembly: Install the Pilot Diaphragm with
convex side toward Diaphragm Plate and Main Spring (Refer
to Figure 9). Tighten nut on the Diaphragm Retainer to
approximately 5 to 6 ft-lbs. (6.78 - 8.1 n-m) torque.
NOTE: Over-tightening will distort the Pilot Diaphragm
.
Figure 9
- The orifice can be pushed out of the Body
Insert (Cartridge) using a paper clip.
Spring
Nut
Diaphragm Plate
Diaphragm
Diaphragm Retainer
Figure 8
- A paper clip, or pick
easily extracts the O-Ring out of
the pilot body.
Figure 10
- Diaphragm Assembly for the 22 Series Pilot.
