IOM-123-1+6 +S DIFF
3
B. Disassembly:
1. Securely install the body (1) in a vise with the
spring chamber (2) directed upwards.
2. Remove closing cap (22).
3. Loosen sealing locknut (9) by rotating CCW.
Relax range spring (18) by turning adjusting
screw (17) CCW.
4. Draw or em bed a match mark be tween
body (1) casting and spring chamber (2)
sub as sem bly along flanged area.
5. Re
move all body flange hardware
(7,8,30,41,42).
6. Re
move spring chamber (2) and connected
parts, range spring (18) and spring but ton
(19).
DO NOT AT TEMPT TO REMOVE ADJUSTING SCREW
(6) FROM TOP OF SPRING CHAM BER (2). The
ad just ing screw (6) is threaded up from inside the
spring chamber (2) and the CCW rotation used to
relieve range spring (14) tension will come to a stop.
At the stop ping point, do not apply any torque to
ad just ing screw (6) or dam age may occur and ren der
the unit in op er a ble.
See Figure 1.
CAUTION
7. Adjusting screw (17) o-ring inspection:
a. With locknut (9) and closing cap (22)
re moved, turn adjusting screw (17) CW
as far as possible by grasping the flats
on top end. Care ful ly reach in side spring
cham ber (2) and grasp ad just ing screw
(17) by hand. Remove ad just ing screw
(17) by rotating CCW. See Fig ure 1A.
b. Inspect the backup ring (28) and quad ring
(29) for wear. If nicked or torn - replace.
NOTE: Make certain the teflon backup
ring (28) will insert into spring cham ber
(2) first, before the quad ring (29). (See
Fig ure 7 blow-up illustration). Make sure
the quad ring (29) is on straight with
no twist. Use a good grade light weight
grease on the ring seals (28,29).
c. Lubricate adjusting screw (17) threads.
Carefully re in stall adjusting screw (17)
up into the spring cham ber (2) by ro tat ing
adjusting screw (17) CW until top of
ad just ing screw (17) protrudes from top
of spring chamber (2) (See Fig ure 1B.).
NOTE: Care should be taken when
hold ing and ro tat ing adjusting screw (6)
so the quad ring (29) and back up ring
(28) are not in ad vert ent ly nicked or torn.
Grasp top of ad just ing screw (17) and turn
CCW until rotation stops
(see CAUTION
C)
.
d. Loosely install the lock nut (9) and closing
cap (22).
8. Lift up and remove the diaphragm sub as sem bly
con sist ing of the pis ton (14), piston nut (6),
di a phragm (3), di a phragm cov ers (24) (NACE
unit only, Cashco Dwg. 32934), pres sure
plate (20), pusher plate (21), seal ing washer
(27), pres sure plate o-ring (31) and pusher
plate o-ring (34). Re move the flange o-ring
(32).
9. Loosen piston nut (6) and separate all parts
(3,24 (NACE units only),14,20,21,27,31,34)
of the diaphragm (3) sub as sem bly.
Figure 1:
Adjusting screw (17) o-ring inspection.
9
28
29
28
29
9
17
17
2
B.
Reassembly
A.
Removal
2
When body flange hardware (7,8,30,41,42) is re moved
from this unit it should al ways be re placed with new.
The new hardware (7,8,30,41,42) must have the prop er
grade spec i fi ca tion iden ti fi ca tion mark ings and meet
the following stan dards:
1. All cap screws (7,30) and flange stud nuts (8)
must have "heavy hex heads".
2. All studs (41,42) and cap screws (7,30) must
comply with or exceed the requirements of
ASTM-A-193, Grade B7.
3. All flange stud nuts (8) must comply with
or exceed the requirements of ASTM A-194,
Grade 2H.
New body flange hardware (7,8,30,41,42) may be
pur chased from Cashco, Inc. or through the OEM.
CAUTION
