Cashco DA5 - Manual (Page 5)

IOM-DA5 5
B. Main Valve Disassembly:
1. Shut down the system in accordance with
Section VI.
2. Disconnect the external sensing line, if in-
stalled.
3. Though it is possible to disassemble the regu-
lator while installed in a pipe line, it is rec om-
mend ed that main te nance be done in a shop
when pos si ble. The de scrip tions here af ter will
assume shop dis as sem bly. Remove regulator
from pipe line.
4. Place the body (23) in a vise with the spring
chamber (4) oriented upwards.
5. Loosen adjusting screw lock nut (2) and relax
range spring (6) forces by turning adjusting
screw (1) CCW (viewed from above) until
removed from spring chamber (4).
6. Loosen the diaphragm fl ange bolts (11) and
nuts (12) uniformly.
7. Place matchmarks on body (23) and spring
chamber (4) fl anges. Com plete ly remove bolt-
ing (11,12) Re move the spring cham ber (4).
8. Remove spring follower (5) and range spring
(6).
9. Grasp opposite edges of diaphragm (9) and
withdraw the ITA from within the cage (19).
Set the ITA aside.
10. Evenly loosen the cage cap screws (18) in
single revolution increments until fully loos-
ened; remove cage cap screws (18).
11. Pull cage (19) up and out of body.
12. Remove o-ring cage seal (15).
13. Remove lower cage gasket (21).
14. If supplied, remove internal sensing drilled plug
(32) using 5/32" (4 mm) Allen key wrench for
1/2" - 2" size regulators. Use 3/16" Allen key
wrench for 2 1/2" - 4" size regulators.
NOTE: Valves with “Large Internal Sensing” will not
be equipped with any plug (32,33).
15. For metal diaphragm constructions, remove
diaphragm gasket (37) from body (23) di a -
phragm fl ange.
16. Remove body (23) from vise. Solvent clean
all removed metal parts.
C. Disassembly of the ITA:
1. Body Sizes 1/2" – 2". (See Figures 3 and 4):
a. Obtain two pieces of square-section
barstock with a 3/8"-7/16" dimension,
approximately 2 inches long.
b. Place plug (20) into a vise using the bars
of a. above, use "fl ats" located on plug
(20) to prevent vise jaw marks from direct
surface contact with the plug (20). Orient
with diaphragms on topside.
c. Sizes 1/2"-1": Remove diaphragm lock nut
(7) by rotating CCW.
Sizes 1-1/4"-2": Remove diaphragm cap-
screw (7) by rotating CCW.
d. Remove upper diaphragm pressure plate
(8).
e. Remove diaphragm(s) (9, 9.1, 9.2, 9.9).
Examine diaphragm(s) to determine
wheth er failed; determine if op er at ing
conditions are ex ceed ing pressure drop
or temperature lim its.
f. For composition diaphragm con struc tion,
remove upper stem seal (14.1).
g. For metal diaphragm con struc tion, re move
lower pusher plate gasket (14.4).
h. Remove lower diaphragm pusher plate
(10).
i. Remove middle stem seal (14.2).
j. Remove plug (20) from vise, ro tate end-
for-end, and resecure in vise using same
metal bars above.
k. Loosen seat disc nut (30) CCW (viewed
from above) ap prox i mate ly two (2) rev o -
lu tions.
l. Remove assembly (20, 27, 28, 29, 30)
from vise. Complete re mov al of seat disc
nut (30), seat disc washer (29), and seat
disc (28).
2. Body Sizes 2-1/2" – 4". (See Figure 2):
a. Place seat disc nut (30) into a vise with
the plug (20) oriented ver ti cal ly. DO NOT
over-tighten nut (30) in vise.
b. Place closed-end hex wrench onto di a-
phragm locknut (7). Place sock et wrench
on hex upper end of plug (20). Loos en
diaphragm lock nut (7) while holding plug
(20) from ro tat ing by socket wrench.
WARNING
SYSTEM UNDER PRESSURE. Prior to per form ing any
maintenance, isolate the reg u la tor from the sys tem and
relieve all pressure. Failure to do so could result in per-
sonal injury.*
* Includes external sensing connection if applicable.