IOM-PGR-1
7
1. Shut down system in accordance Section VI.
2. Disconnect the external sensing line, from the
pilot valve sensing port.
3. Loosen all fittings and remove tubing that con-
nect the inlet filter to the stabilizer, the cover
dome to the metering valve and the outlet of
the metering valve to the outlet of the body.
4. Loosen and remove the two nuts (24) that
secure the mounting bracket (3) and pilot to
the cover dome (2).
5. Remove pilot assembly from main valve.
6. Place the pilot valve body (30.1) in a vise with
the spring chamber (30.2) upwards.
7. Loosen adjusting screw nut (30.18) one revolu-
tion CCW. Relax range spring (30.4) forces
by rotating adjusting screw (30.17) CCW until
removed from spring chamber (30.2).
8. Loosen the diaphragm flange bolts (30.19) and
nuts (30.21) uniformly and remove bolting.
9. Place match marks on body (30.1) and spring
chamber (30.2) flanges. Remove spring cham-
ber.
10. Remove spring button (30.5), range spring
(30.4) and pressure plate (30.6).
11. Remove diaphragm (30.13). Examine dia-
phragm to determine whether failed; determine
if op er at ing conditions are exceeding pressure,
pressure drop or temperature limits. If just
replacing the diaphragm, proceed to Step H.9
and skip the following instructions.
12. Grasp pusher post (30.12) and lift up to remove.
Place socket wrench over retainer (30.10) and
rotate CCW to remove from body.
13. Remove seal gasket (30.15), piston seal
(30.14) and a second seal gasket (30.15) from
bore inside the body.
14. To remove the stem (30.8), remove the body
from the vise and slowly turn upside down.
Stem will slide out of the body, Do Not let the
stem fall and hit the floor.
15. Place body (30.1) in a vise with the body cap
(30.3) upwards. Rotate cap bolts (30.20) CCW
to remove bracket and body cap. Remove
cap seal (30.16).
16. Remove return spring (30.11), ball holder
(30.9), and ball (30.22).
17. Place socket wrench over seat (30.7) and
rotate CCW to remove from body.
18. Remove body (1) from vise. Clean all re us able
metal parts according to owner's pro ce dures.
H. Pilot Valve Reassembly:
1. Place body (30.1) in a vise flange face down.
2. Apply "Gasoila" or equivalent, thread sealant
to the threads of the seat (30.7). Engage the
seat threads into the body and apply 20 - 25
ft-lbs. torque. Place the ball (30.22), ball
holder (30.9) and return spring (30.11) onto
seat.
3. Place the o-ring (30.16) into the groove in
the body cap (30.3) and place onto the body.
Position the bracket on the body cap and
re-install cap bolts (30.20). Make sure the
return spring (30.11) fits inside the bore of
the body cap. Tighten nuts evenly in a star
crossing pattern. Apply 15 - 18 ft-lbs. torque
to tighten the cap bolts.
4. Remove body from the vise. Reinstall body
again in vise with the bolt flange facing up.
5. Insert the stem (30.8) into the center hole
of the body and the seat (30.7), square end
first.
6. Place one seal gasket (30.15), one piston
seal (30.14) and one seal gasket (30.15)
into the center bore on top of the stem (30.8).
See Detail "A". Ensure to align the seal
and gaskets so they are centered inside the
threaded bore hole.
7. Engage the retainer (30.10) threads into the
center bore hole to hold the piston seal and
gaskets in place and apply 75 in-lbs. torque.
to tighten.
8. Insert pusher post (30.12) into retainer
(30.10).
9. Place diaphragm (30.13) on bolt flange,
centered between bolt holes. Center the
pressure plate (30.6) on top of the diaphragm.
10. Place range spring (30.4) in center of the
pressure plate (30.6) cup. Apply Mobile XHP
