14 | GE Oil & Gas
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Maintenance
(cont’d)
Assembly
1. Disconnect control lines(s) and pilot supply line from
pilot system.
2. Loosen main spring case nuts in a crisscross pattern.
The main spring will lift the spring case as the nuts
are removed.
3. Remove spring, diaphragm/throttling element,
spacer, throttle plate and O-rings in that order.
4. Inspect all parts for wear and damage. Replace as
necessary.
NOTE: The periphery of the downstream (outlet)
portion of the throttling plate is the primary shutoff
surface and should be inspected most closely for wear
and damage. Nicks and/or wear on the support ribs
will usually not affect shutoff.
The outside “rib” on the downstream side of the throttle
plate is where shutoff takes place in the Flowgrid
Regulator.
NOTE: Nitrile O-rings can swell after disassembly
of a regulator that has been in service (due to
gas permeating the nitrile rubber). This does not
necessarily mean they must be replaced. Set O-ring
aside for several hours and it will gradually return
to normal size. Placing the O-ring(s) on ice will speed
the process considerably. Before placing the O-ring
back into service inspect for defects.
Cleaning
1. DO NOT clean O-ring grooves with sharp metal
tools. The bottom of the groove must have a
smooth finish to prevent leakage. The mating
surface of adjacent parts must also be smooth to
prevent leakage.
Assembly
NOTE: Do not lubricate diaphragm sealing surface.
1. Reassemble parts on the body per the assembly
drawing in the parts supplement for the particular
regulator size.
NOTE: Both the throttle plate and the diaphragm can
be rotated 180 degrees (not turned upside down) to
renew the shutoff capability if the inlet side is in better
condition than the outlet.
2. Tighten main bolts in increments using a crisscross
pattern. Torque bolting as indicated on regulator
nameplate (or refer to Table 6).
Bolting Torque Values
Clean Dry Bolts- Non-Lubricated
Regulator Size
Min. Torque
Ft/Lbs (n-m)
Flowgrid 250
20 (27.09)
1” (ALL)
1
25 (33.86)
2’ x 1” (ALL)
1
25 (33.86)
2” (ALL)
1
60 (81.26)
3” (ALL)
1
125 (169.28)
4” x 3” (ALL)
1
125 (169.28)
4” (ALL)
1
125 (169.28)
6” CL 150 & CL 300 Flanged
125 (169.28)
6” CL 600 Flanged
200 (270.86)
10” CL 150 & CL 300 Flanged
125 (169.28)
10” CL 600 Flanged
200 (270.86)
12” CL 150 & CL 300 Flanged
125 (169.28)
12” CL 600 Flanged
200 (270.86)
All Flowgrid Pilots
10 (13.54)
1
Refer to WARNING below.
Table 6
WARNING
Overtightening the bolting can damage the diaphragm
in the 1” and 2” sizes of the Flowgrid
regulator.
WARNING
DO NOT replace the studs or nuts with any bolt or
stud and nut combination that does NOT have an SAE
Grade 7 or ASTM Grade B7 rating.
3. Reconnect the pilot system. Follow Start up
procedures when returning to operation.
