Cashco 5400 User Manual
Page 5

5
IOM-5400
9. Install another new diaphragm (207) on
piston stud (230) and align the bolt holes
with parts of previous Steps 6 and 7.
10. Stack the upper pressure plate (246), the
wrench washers (228), the spring guide
(211) and piston stud lock washer (242)
over the piston stud (230).
11. Install and tighten piston stud nut (235) to
secure all parts. (Check alignment of the
bolt holes around the circumference.)
12. Position the range spring (215) and spring
button (212) on the spring guide (211).
13. Place diaphragm pressure ring (250) on
top of diaphragm (207).
14. Lower the upper diaphragm case (202) /
spring bonnet (204) assembly over the
spring (215), allow to rest on the diaphragm
pressure ring (250). (Ensure alignment of
match marks per previous B.3.)
15. Install diaphragm case screws (220), fl at
washers (221), lock washers (210) and
nuts (209) and tighten.
16 Apply a light coat of Bostik Never-Seez
to threads of blowndown needle (217).
Thread completely into body until the nut
(236) contacts the body (201) and then
back out two rotations. Rotate nut (236)
CW to secure nut tight.
17. Reinstall adjusting screw (213) and jam
nut (214) in spring bonnet (204).
18. Refer to Section IX for Calibration and
Testing
19. Install pilot body assembly on nipple (53)
tight with CW rotation. Ensure straight
connector (244) of the pilot valve assembly
is directly above sensing tube connector
(48) of the main valve assembly.
20. Reconnect tubing (243) to fi ttings (232),
(234) and tubing (57) to fi ttings (48),(244).
.
16. From opposite end of assembly use 1/8”
allen wrench to remove retaining screw
(229) and piston cap (223). Remove and
replace with new seat O-ring (233).
17.
Rotate blowndown needle jam nut
(236) CCW two rotations and remove
blowndown needle (217) from body (201).
Replace with new O-ring (218).
C. Re-assembly:
1. Install piston cap (223) and retaining
screw (229) into piston (208).
2. Lightly coat cylinder (227) bore with Dow
Corning Molykote 22 lubricant and insert
piston (208) through lower opening of the
cylinder (227) and press into place.
3. Position new body gasket (225) on top of
pilot body, align gasket holes and slide
piston (208) / cylinder (227) assembly
into the body (201). DO NOT COVER
SENSING HOLE.
4. Position another body gasket (225) on top
of cylinder fl ange. Align holes in the lower
diaphragm case (203) with the cylinder
and body. DO NOT COVER SENSING
HOLE. Use lock washers (240) and cap
screws (238) to secure lower diaphragm
case (203) tight to the body. (201).
5. Install new lower diaphragm gasket (226)
and one diaphragm washer (219) on
piston stud (230).
6. Place a new diaphragm (207) and the
lower pressure plate (206) on piston stud.
7. Install diaphragm spacer (247), a new
upper diaphragm gasket (226) and
diaphragm washer (219) on pIston stud
(230).
8. Place the large spacer (245) above the
diaphragm and align match marks per
previous B.3.
For Intermediate & High Pressure Pilots Only:
Install diaphragm case gasket (255) and
pressure ring (251).