IOM-POSR-1
7
nuts (18) onto bolts (17) along un der neath
side of body (1) flange and finger-tighten.
40. Remove the two upside-down bolts (17) and
nuts (18) and rotate to position of other bolts
(17). Place nameplate tag (21) over one of
the bolts (17) before replacing into bolt hole.
Fin ger-tighten nuts (18).
41. Observe through opening in top of spring
cham ber (2) to ensure the concentricity of the
recess in the spring button (16) with the top
opening. It may be necessary to use an awl
or similar tool to realign the spring button (16)
as much as possible. The spring cham ber (2)
is not tightened down, and may be temporarily
“shifted” to help ensure alignment for the
adjusting screw (19) en gage ment.
42. Place lubricant onto the upper exposed
threads of the spring chamber’s (2) ad just ing
screw (19) opening. Place lu bri cant onto
the ad just ing screw (19) lower-end threads.
Engage adjusting screw (19) back into spring
cham ber (2) by rotating CW (viewed from
above). Engage only until resistance is made
with the range spring (15) via the spring button
(16).
43. Realign the spring chamber (2) flange with the
body (1) flange, and wrench-tighten bolting
(17, 18) in an al ter nat ing, crossing pattern.
Final tightening should be done with a torque
wrench to 15 ft.-lbs. (20 N-M).
D. Main Valve (MV):
1. Securely install the body (1) in a vise with the
loading chamber (2) directed upwards.
2. Draw or embed a match mark between body
(1) casting and spring chamber (2) casting
along flanged area.
3. Remove all cap screws (14) and nuts (15).
4. Remove loading chamber (2), diaphragms
(12), diaphragm gaskets (13) and pusher
plate (11). Clean body (1) and diaphragm (12)
flange surface.
5. Rotate cap screws (10) CCW to remove, lift
shield plate (9) out of body (1) cavity.
6. Remove body (1) from vise, rotate body (1)
with body cap (4) directed upwards and re-
secure body (1) in vise.
7. Loosen and remove body cap (4) using a hex
head wrench with a lever length of at least 15"
inches. The wrench should be rapped with a
hammer to loosen.
8. Remove piston spring (6), piston (3.2) and
cylinder (3.1). Inspect parts for excessive
wear, especially at seat surfaces. Replace if
worn.
9. Remove the cylinder gasket (8) and clean
contacting surface in body (1).
10. Clean flat mating surfaces of body (1) to body
cap (4) shoulder.
11. Clean debris from within body (1) cavity and
all parts to be reused.
12. Reinstall a new cylinder gasket (8). Use
the cylinder (3.1) to firmly and evenly press
the gasket (8) into place. Gasket surfaces
maybe lightly coated with pipe sealant prior
to in stal la tion.
13. Ensure cylinder (3.1) is concentrical within the
body (1) opening. Slide the piston (3.2) into
the cylinder (3.1).
14. Place piston spring (6) into piston cavity.
15. Apply pipe thread sealant to body cap (4)
threads and screw into body (1). When body
cap (4) shoulder is resting fully down against
body (1), use a wrench with 15" lever handle
and a hammer to impact the body cap (4) tight
WARNING
Never replace bolting (17, 18) with just any bolting if
lost. Bolt heads and nuts are marked with spec i fi ca tion
identification markings. Use only proper grades as
replacements.
44. Continue CW rotation (viewed from above) of
ad just ing screw (19) until locknut (20) touches
spring chamber (2). Back adjusting screw (19)
out by rotating CCW (viewed from above) two
revolutions. This position will ap prox i mate the
pressure setpoint prior to dis as sem bly if the
locknut (20) is only loosened two revolutions as
directed in article 2. previous, this sub-section.
45. Pressure leak test pilot valve (PV) assembly
when rejoined with the main valve (MV)
as sem bly including interconnecting nipple
(19), tubing (21), and tubing fittings (20).
