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6. Slide the travel indicator bushing (key 38) over the
travel indicator stem (key 34) and tighten firmly in
place with a torque of 3.7 ft-lbs / 5.0 N•m.
7.
Replace the travel indicator cover (key 40) and
tighten firmly in place.
PRX Series Pilot Maintenance
CaUTiOn
always remove spring (key 7) tension
before performing maintenance on this
unit. To remove spring tension, loosen
locknut (key 2) and back out adjusting
screw (key 1) until compression is
removed from the spring.
note
apply an anti-seize compound to the
adjusting screw threads and other areas
as needed.
Lower Case Maintenance
1. Remove pressure from the pilot.
2.
Remove screws (key 10) from lower cover (key 21)
and the separate lower cover from the body (key 16).
3. Use a wrench to hold the stem (key 23) and break
loose the stem nut (key 20). Remove the stem nut
and washer (key 11).
4. Remove the upper diaphragm plate (key 13),
diaphragm (key 14), pad holder (key 22) and
O-ring (key 18). Inspect the parts for damage or
wear and replace if necessary.
5. Remove orifice (key 19) and O-ring (key 17).
Inspect the parts for damage or wear and replace
if necessary. Lightly lubricate the O-ring and place
in the body (key 16). Install the orifice.
6. Set the pad holder (key 22) in the body (key 16).
7.
Lightly lubricate the rims of the diaphragm (key 14)
and place it on top of the pad holder (key 22).
Set the upper diaphragm plate (key 13) on the
diaphragm (key 14).
8. Lightly lubricate the O-ring (key 18) and place it in
the lower case (key 21).
9.
Place the washer (key 11) and stem nut (key 20)
on the stem (key 23) and tighten.
If also performing
Upper Case Maintenance, skip to step 2 of the
Upper Case Maintenance section.
10.
Insert machine screws (key 10) in the lower
cover (key 21) and tighten uniformly to ensure
proper seal.
Upper Case Maintenance
1. Remove pressure from the pilot.
2.
Loosen locknut (key 2) and back out adjusting
screw (key 1) until compression is removed from
the spring. Remove cap (key 3).
3. Lift the upper spring seat (key 6), spring (key 7)
and O-ring (key 4) out of the upper cover (key 8).
Inspect O-ring and replace if necessary.
4. Remove machine screws (key 10) from lower
cover (key 21) and the separate lower cover from
the body (key 16), unless removed during lower
diaphragm maintenance. Use a wrench to hold
stem (key 23) securely while removing the stem
nut (key 26).
5.
Remove remaining loose components: washer,
upper diaphragm plate, diaphragm, lower
diaphragm plate and O-rings (keys 11, 13, 14, 15,
18 and 25). Inspect diaphragm and O-rings for
damage or wear and replace if necessary.
6. Lightly lubricate the O-ring (key 25). Place O-ring
over the stem (key 23) and press it down into the
body (key 16).
7.
Set the lower diaphragm plate (key 15) into the
body (key 16).
8. Lightly lubricate the rims of the diaphragm (key 14)
and place it in the body (key 16) on top of the lower
diaphragm plate (key 15).
9.
Set the upper diaphragm plate (key 13) on top of
the diaphragm (key 14).
10.
Place washer (key 11) and stem nut (key 26) on
the stem (key 23) and tighten using a wrench to
hold the stem.
11.
Place the lower spring seat (key 9) on the upper
diaphragm nut (key 26) and mount the upper
cover (key 8) on top of the body (key 24) and the
diaphragm (key 14).
12. Place and uniformly tighten the machine
screws (key 10) to hold the body (key 24) and
upper cover (key 8) together. Position the
diaphragm convolution facing down and make
sure that the diaphragm is not deformed and is
properly installed.
13. Install spring (key 7) and upper spring seat (key 6)
on top of the lower spring seat (key 9) inside the
upper cover (key 8). Install cap (key 3).
13
Type FL
North America
Only