INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F7000 / 8000 Series Rev. T
Pilot-Operated Safety Relief Valve Page 13 of 43
6) If the valve is IM construction, reinstall the spool piece with new softgoods. Apply a light coat of
lubricant (Molykote or equivalent) to the seals.
7) If the valve is fitted with a dome spring, reinstall the spring in the piston.
8) After checking placement of the top liner seal [see Step (2)], the valve cap can be positioned on top
of the body.
9) The cap bolts, with washers, can then be reinserted and torqued to the values listed below.
Main Valve Size Cap Bolt Size Torque (ft-lbs) – CS (B7) / SS
1x2, 1-1/2x3 & 2x3 (thru 1500#), 4x6 (thru 300#) 1/2-13UNC * 50 / 25
1-1/2x3 and 2x3 (2500#) 5/8-11UNC * 65 / 45
3x4, 4x6 (600-1500#), 6x8, 8x10, 10x12, 12x16 3/4-10UNC * 120 / 80
* UNF thread on older valves
10) If removed previously, reinstall the pilot valve and tubing. The pilot mounting bolts should be
treated with Loctite or Vibra-tite, if available, and firmly tightened.
11) The main valve is now completely assembled, and should be tested per Section 6.0 before being
returned to service.
4.0 PILOT VALVE MAINTENANCE
4.1 F100 PILOT VALVE
(See Illustration on Page 14)
A. F100 Disassembly
CAUTION: It is extremely dangerous to attempt to disassemble any valve while it remains in
service with incoming line pressure.
1) Remove the pilot valve from the main valve, or safely block the incoming pressure before
disassembling the valve and performing maintenance.
2) Unscrew the pressure adjustment screw cap from the pressure adjustment screw. Loosen the lock
nut.
3) Loosen but do not remove the pressure adjustment screw from the pilot valve bonnet.
4) Remove the bolts (also nuts and lockwashers on older bodies) that hold the valve body and bonnet
in place. Separate the bonnet from the body. Remove the spring and two spring washers.
5) With a wrench on the diaphragm lock nut and screwdriver in the top of the spindle, loosen the lock
nut and remove it from the spindle.
6) Remove inner/outer spacer(s) from the top of the valve body. Remove the diaphragm from the
spindle by unscrewing it counter-clockwise.
7) Turn the pilot valve body over and remove the nozzle and spindle. Unscrew the retainer screw
from the spindle. Remove the retainer and seat.
8) Replacement soft goods are listed in Section 8.0 of this manual.
B. F100 Assembly
NOTE: Exercise care in handling softgoods, nozzles, and other sealing surfaces.
1) Confirm pressure setting and associated parts required.
2) Place the valve body in a vise.
3) Apply Loctite 248 to retainer screw. Place the spindle, with the retainer and seat screwed into
place into the valve body, and assemble the nozzle (with seal and O-ring) into the body. Dow
Corning Molykote 33 or equivalent may be used to lubricate O-rings.
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