Bulletin 22-05 A / Page 7
Item No.
Description
Material
Qty
1
Seal Cap
6061 Al
1
2
O-Ring, 0.551 ID x 0.691 OD x 0.07
Neoprene
1
3
Bonnet
304L S.S.
4
4
M6 x 18MM Bolt
DIN-ISO Standard
3506-1
1
5
O-Ring, 0.25 ID x 0.35 OD x 0.062
Neoprene
1
6
Washer, 0.39 ID x 0.625 OD x 0.031
Acetal
1
7
Stem
303 S.S.
1
8
Top Plate, Spring with Roll Pin
1215 Steel
1
9
Spring, Bonnet
Music Wire ASTM -228
1
10
Bottom Plate, Spring
1215 Steel
1
11
Ball, 0.281 DIA
440C S.S.
1
12
Follower, Diaphragm
1215 Steel
1
13
O-Ring, 1.5 ID x 1.625 OD x 0.062
Neoprene
1
14
Gasket, 1.875 ID x 2.3 OD x 0.015
Klingersil C-4401
1
15
Diaphragm
301/302 S.S.
1
16
O-Ring, 2.0 ID x 2.125 OD x 0.062
Neoprene
1
17
O-Ring, 0.25 ID x 0.375 OD x0.062
Neoprene
1
18
Plug, Pilot (A4WO Only)
303 S.S.
1
18A
Plug, Pilot
(A4WB, A4WS, & A4WBS Only)
303 S.S.
1
19
Seat, Pilot
1215 Steel
1
20
O-Ring, 0.437 ID x 0.563 OD x 0.062
Neoprene
1
21
Spring, Pilot
S.S. ASTM A-313
1
22
Seal Cap
6061-T6 Al
1
23
O-Ring, 0.813 ID x 0.938 OD x 0.062
Neoprene
1
24
Seat, Pilot Plug (“S” Only)
303 S.S.
1
25
Bolt, M10 x 45MM
DIN-ISO Standard
3506-1
4
26
Plug, Gauge 1/4” NPT
PTFE Coated Steel
1
27
Plug, Pipe 1/16” NPT (A4WO Only)
Black Oxide
Finish Steel
1
28
O-Ring, 0.125 ID x 0.25 OD x 0.062
Neoprene
1
29
Stem, Manual Opening
303 S.S.
1
30
Nut, Retainer
416 S.S.
1
31
Plug Cap, Manual Opening 7/16-20
6061-T6 Al
1
32
Pin, Roll
420 S.S.
1
33
Seat, Solenoid
303 S.S.
1
34
Port Plate
6061-T6 Al
1
35
Gasket, Port Plate 0.031
MP 15
1
36
Ring, Retaining 2.174 Internal
302 S.S.
1
37
Ring, Backing
302/304 S.S.
1
38
Ring, Seal 2.528 ID x 2.706 OD
PTFE S.S.
1
39
Spring, Piston
Music Wire
ASTM A-228
1
40
Piston
303 S.S.
1
41
Ring, Seal
Tefl on (PTFE)
1
42
Ring, Wear
PTFE EMS-103
1
43
Body
304L S.S.
1
A4WO, A4WOB, A4WOS, A4WOBS Parts List
access to the pilot assembly (#17 – 21)
on an A4WO is required, then the
compression must be taken off the
range spring as described above, and
the bonnet bolts (#4) removed. If a
solenoid fea ture is incorporated, the
solenoid coil (#45) should now be
removed by removing the coil clip
(#44). Never energize a solenoid coil
that is not mounted and secured on its
solenoid actuator (#46).
After removing the bonnet assembly
bolts, the bonnet can be easily
lifted off , and will usually leave the
diaphragm resting on top of the gasket
(#15) and o-ring (#16). Th
e bolts (#25)
retaining the lower sub-assembly can
now be removed. Th
e wear aspects of
the port plate (#34) are the diaphragm
and the pilot assembly, which is
pressed into the top of the port plate.
Remove the diaphragm and inspect
carefully for cracks, or scarring around
the pilot seat area. Th
is is most easily
done by looking down a piece of
large tubing, through the diaphragm,
at a safety lamp or similar light
source. Inspect the pilot seat area of
inlet regulators for erosion or other
damage; it should be dead smooth to
maintain a good metal-to-metal seat.
Removal of the port plate may require
a sharp tap on their sides to unseat the
parts from their sealed position, for
which a rubber or rawhide hammer is
recommended so as to avoid damage
to the sealing surfaces. Removal of
the port plate will expose the top of
the piston. Th
e piston spring (#39)
and piston (#40) should be removed
and inspected. Continue to inspect
the wear ring (#42), metal rings, and
gaskets.
Before re-assembly, all parts must
be cleaned with a suitable solvent,
permitted to dry, and lubricated with
a light fi lm of refrigerant oil, simply
wiped on with the fi ngers, All gaskets
and o-rings should be renewed, and
insertion and sealing will be facilitated
if a similar fi lm of oil is applied to
them as well.
Re-assembly is exactly the reverse
of disassembly, with the precaution
that the reliefs cut into each module
of the valve assembly and the
