IOM-POSR-2
6
2. Loosen locknut (20) by rotating CCW (viewed
from above) ONLY two revolutions. Relax
range spring (15) by turning adjusting screw
(19) CCW (viewed from above) until removed
from spring chamber (2). Set ad just ing screw
(19) with locknut (20) aside.
3. Draw or embed a match mark between body
casting (1) and spring chamber casting (2)
along flanged area.
4. Remove all diaphragm flange nuts (18) and
bolts (17).
5. Remove spring chamber (2) by lifting up wards.
Re move range spring (15) and spring button
(16).
6. Remove pressure plate(14). Inspect to en sure
that the pressure plate (14) has not been
deformed by overpressure by placing a
thin, straight bar or ruler across the side that
touch es the diaphragm (12). If the pressure
plate (14) does not touch the bar at its center
(i.e. a depression in center), the pressure plate
(14) is deformed and must be replaced.
7.
NOTE:
Pilot valves (PV) supplied with a 5–15
psig (0.34–1.03 Barg) range spring (15) have
only one di a phragm (12) supplied; all other
spring ranges use two diaphragms (12).
Using a putty knife or similar tool, remove
diaphragm(s) (12) and diaphragm gasket
(13). Inspect diaphragm(s) (12) for cracks
or de for ma tion. Radial creases and cracks
indicate over pressure. Cracks circumferentially
in di cate high cycles, and may be due to normal
cycling, or pulsing or chattering if premature.
Discard both diaphragm(s) (12) and gasket
(13).
7. Remove pilot valve (PV) from vise and set
aside.
C. Pilot Valve (PV):
1. Securely install the pilot valve body (1) in
a vise with the spring chamber (2) directed
upwards.
8. Using a 7/8" deep well socket, remove bel lows
(11) by rotating CCW (viewed from above).
Count and record the number of revolutions
required to remove the bellows (11) in the box
below:
Number of revolutions required to remove
bellows (11):________________.
Inspect the bellows (11) for a crack or joint
failure where leakage is occurring. Replace
bellows (11) if leaking.
9. Remove protruding stem extension (10).
10. Using a flat, sharp-edged tool, clean body (1)
flange where diaphragm gasket (13) seals.
11. Using a wire gauge tool, clean the 0.068"
(1.73 mm) diameter bleed orifice located in
the body cavity (smaller of two holes) of any
film or other buildup material that might be
restricting flow.
NOTE:
Any significant blockage of the
bleed or i fice will downgrade a POSR-2’s
per for mance. If a buildup is form ing, attempt to
determine the cause and remove the source.
12. Remove body (1) from vise and reorient with
body cap (9) on top; resecure body (1) in vise.
13. Remove body cap (9) by rotating CCW (viewed
from above) with hex-end wrench. Hammer-
rapping the wrench may be necessary, as the
body cap (9) has a metal-to-metal shoulder
joint with the body (1).
NOTE:
Plug (4.2) and
plug spring (7) may come out with body cap
(9) removal.
14. Remove plug spring (7) and plug (4.2) from
body (1) recess.
15. Using needle nose pliers, carefully remove
the screen (6) from the body (1) recess.
16. Inspect body cap (9), screen (6), plug spring
(7), and plug (4.2) for buildup or filming. If
parts are “sticking” together, then improper
condensate corrosion treatment is likely.
If scale or other debris is present, then an
up stream strainer is recommended.
17. Using a 5/8" deepwell socket, rotate valve seat
(4.1) CCW (viewed from above) to re mov al.
18. Remove seat gasket (8) using a tool with a
bent sharp end. Discard the seat gasket (8).
WARNING
SPRING UNDER COMPRESSION. Prior to re mov ing body
flange bolts, relieve spring com pres sion by backing out
the adjusting screw. Failure to do so may result in flying
parts that could cause personal injury.
