Parker A4WO User manual

Contact Information:
Parker Hannin Corporation
Refrigerating Specialties Division
2445 South 25th. Avenue
Broadview, IL 60155-3891
phone [phone]
fax [phone]
www.parker.com
Product Bulletin 22-05 A
Outlet Pressure Regulator
Type: A4WO, A4WOB, A4WOS, A4WOBS, A4WOK,
A4WOBK, A4WOE, A4WOES
Size: 20 - 50 mm (3⁄4” to 2”)
Design Pressure Rating: 32 bar (464 psig)
Purpose:
The A4WO outlet pressure
regulators modulate the ow of
refrigerant gas or liquid to maintain
a constant downstream pressure.
This improved design has a higher
working pressure, greater working
temperature range than competitive
products, and minimizes the effects
of system impurities for a more
durable operation. The A4WOs most
benecial features are its stainless
steel and aluminum construction,
which allows it to withstand corrosive
environments and its overall light
weight minimizes installation costs.
Product Features:
Suitable for Ammonia, CO •
2, R-22,
R-404a, and other common
refrigerants
Designed with corrosion resistant •
material – 304 stainless steel and
aluminum
No body wearing surfaces •
Stainless steel components are •
resistant to wiredrawing
Improved performance at low loads •
with a turn down ratio of 10% of
capacity
Design drastically reduces foreign •
material to ow from inlet to
diaphragm/seat and piston cavity
Light weight •
Can be mounted in a horizontal •
and vertical position
Several control options available •
Fluid temperature rating: -60 •
oC to
116oC (-76oF to 240oF)
Ambient temperature rating: -40 •
oC
to 60oC (-40oF to 140oF)
Complies with Pressure Equipment •
Directive 97/23/EC
A4WOB
A4WOS
A4WO
A4WOB
A4WOBS
Patent Pending

Page 2 / Bulletin 22-05 A
Port Size Connection Size
(SW, BW) Body Size Kv Cv
20 mm (3/4”) 3/4”, 1” 1” 10.8 12.6
25 mm (1”) 3/4”, 1”, 1-1/4” 1”, 1-1/4” 12.5 14.6
32 mm (1-1/4”) 1-1/4”, 1-1/2” 1-1/4”, 2” 22.3 26
40 mm (1-1/2”) 1-1/2”, 2” 2” 30 35
50 mm (2”) 1-1/2”, 2” 2” 41.1 48
A4W Port, Connection, and Flow Coefficient Table
A4WO Outlet Pressure Regulator Cross Section
(1-1/2” Valve Body Shown)
Seal
Cap
Bonnet
Assembly
Diaphragm
Outlet
Pressure
Passage (N)
Closing
Spring
Modulating
Plug (Piston)
Stainless
Steel Body
Gauge
Port
Aluminum
Port Plate
Adjustment
Stem
Passage (T)
Passage (P)
Inlet Pressure
Passage (N)
Pilot Plug
Description
All A4WO outlet pressure regulators
are pilot operated and require a
minimum of 0.14 bar (2 psig) pressure
drop across the valve to fully open.
e valves are an integrated assembly
of three modules:
A body, which contains the1.
modulating plug, but is ordered to
suit a particular connection size.
e port size denes the size of
the body;
A port plate, which denes the2.
valve function. Control features
can be added by incorporating
pilot solenoids: either an Electric
Shut-O (S) or a Electric Wide
Open Bypass (B);
e bonnet, which contains the3.
range set spring and adjustment
stem.
e A4WO is a normally closed valve
furnished with socket weld and weld
neck options only. is unique design
allows the regulator to be welded
into the line without disassembly, yet
provides full access for cleaning and
servicing from the top only.
ese valves will modulate to maintain
a pressure as set for in the eld, in
spite of uctuations in load, changes
in ambient, changes in available
refrigerant ow paths, and other
operating variances. Appropriately
sized, these valves will modulate the
ow of liquid or vapor, high side or
low side in a wide variety of system
arrangements. Each port size will
have a specic maximum capacity
at full opening corresponding to the
available or sensible-pressure.
e throttle range on this new design
is greatly enhanced, resulting in
optimal performance at low load
conditions. Current regulator designs
can regulate down to 20% of a valves
maximum rating. e A4W series or
regulators can regulate down to 10% of
the valves maximum capacity.
ese valves are generally ordered
with close upstream strainer to
prevent entrance of foreign material
into the valve and the rest of the

Bulletin 22-05 A / Page 3
A4WO Principle of Operation
e outlet pressure enters the space
under the diaphragm through passage
(T), shown in the A4WO principle
of operation cross-section diagram,
lling the chamber underneath the
diaphragm. When force created by
this pressure acting on the underside
of the diaphragm exceeds the force
of the range spring acting on top of
the diaphragm, the diaphragm moves
upward. is also results in an upward
movement of the spring loaded pilot
plug installed directly underneath the
diaphragm. e upward movement
of the pilot plug forces the pilot
plug piston to close, preventing any
pressure above the piston to escape
through passage (P) and into passage
(T). e pressure on top of the piston
is equalized to the pressure below,
inlet pressure, through the piston
bleed hole and the piston moves
downward, closing the valve due to
the weight of the piston and the spring
closing force. A piston seal ring
ensures that this bleed hole is the sole
source of equalization.
Note: the inlet passage (N), shown
in the A4WO principle of operation
cross-section diagram, is blocked o at
the port plate. is passage (N) is used
for the A4W inlet regulator variation
and is not required for a standard
A4WO outlet regulator. A plug is
installed at the factory to prevent any
pilot ow through this passage.
When the outlet pressure decreases,
such that the range spring overcomes
the pressure force underneath the
diaphragm, the diaphragm moves
downward forcing the pilot plug to
move downward opening passage
(P), releasing the pressure above the
piston through the pilot plug and into
passage (T). is lowers the pressure
on top of the piston and the inlet
pressure underside the piston forces
the piston to open.
Note: passage (P) and passage (T) in
the port plate use the same piping
system. e pilot plug prevents both
passages from being utilized at the
same time.
A4WO Principle of Operation Cross Section
A4WOB Principle of Operation Cross Section (‘B’ Coil Energized)
system. (See Bulletin 00-20 for more
information) Passage Description
N Inlet Pressure
P Piston Pressure, Top
TOutlet Pressure
BElectric Wide Open Bypass
SElectric Shut-Off
MManual Opening Stem
A4WO Port Plate Passage Table
N
T
BM
B
Electric
Wide
Open
Manual
Bypass
Stem
Seal Cap
N
T
P
Pilot Plug
Piston
Seat
Diaphragm
Pilot
Spring
Manual
Bypass
Stem
Pilot Plug
Piston
T
P
P
P

Page 4 / Bulletin 22-05 A
A4WOB Principle of Operation
e port plate for the A4WOB is a
slightly dierent construction, shown
in the A4WOB principle of operation
cross-section diagram, than the
standard A4WO, but the regulating
portion of the valve works in the same
manner as described in the A4WO
principles of operation.
Note: the passages in the A4WOB port
plate are not in the same cross-section
as shown in the diagram. e upper
half of passage (B), passage (M), and
the piston pressure release passage
(P) are all located on dierent cross-
sections of the port plate. e cross-
section shown is to better illustrate
how the valve operates.
e ‘B’ feature, electric wide open,
when energized will cause the
solenoid plug to lift and the valve will
fully open. e pressure on top of the
piston is released through passage
(B) and into passage (T), lowering
the pressure. e inlet pressure
acting on the bottom side of the
piston overcomes the outlet pressure,
therefore forcing the piston upward
and fully opening the valve. is
pressure does not feed back through
the pilot plug, because the pilot plug
piston is fully seated.
Simply de-energize the ‘B’ feature on
the valve to regulate.
A4WOS Principle of Operation
e port plate for the A4WOS is the
same port plate used for the A4WOB.
e only dierence is that the seal
cap and coil assembly are located in
the opposite location, as shown in the
A4WOS principle of operation cross-
section.
e ‘S’ feature, electric shut o, when
energized will cause the solenoid
plug to lift and allow the valve to
regulate. e regulating portion of the
valve works in the same manner as
described in the A4WO principles of
operation.
When the ‘S’ feature is de-energized
passage (P) is blocked o and the inlet
pressure bleeds through the bleed hole
in the piston allowing for continuous
equalization of inlet pressure to the
A4WOS Principle of Operation Cross Section (‘S’ Coil Energized)
A4WOBS Principle of Operation Cross Section (‘S’ Coil Energized &
and ‘B’ Coil De-Energized)
Electric
Shut-Off
N
T
BM
B
Manual
Bypass
Stem
Seal Cap
P
P
Electric
Wide
Open
Electric
Shut-Off
N
T
BM
B
Manual
Bypass
Stem
P
P
Passage Description
N Inlet Pressure
P Piston Pressure, Top
TOutlet Pressure
BElectric Wide Open Bypass
SElectric Shut-Off
MManual Opening Stem
A4WO Port Plate Passage Table

Bulletin 22-05 A / Page 5
Manual Opening Stem
ese valves are equipped with a
pressure driven manual opening
system versus the mechanical screw
thread mechanism. A small valve is
opened that allows the inlet pressure
trapped above the piston to escape
via passage (M), through the port plug
and into passage (T), the valve outlet.
top of the piston. e top and bottom
pressure on the piston equalizes and
the weight of the piston along with the
closing spring force prevents the valve
from regulating.
Note: when the ‘S’ feature solenoid
is de-energized the piston remains
closed regardless of the outlet
pressure. Simply energize the ‘S’
feature on the valve to regulate.
A4WOBS Principle of Operation
e port plate for the A4WOBS is the
same port plate used for the A4WOB
and A4WOS. e regulating portion
of the valve works in the same manner
as the A4WOS described earlier. e
A4WOBS principle of operation cross-
section shows the ‘B’ and ‘S’ solenoid
features. When both solenoids are
de-energized, there is no ow from
the top of the piston and therefore
the pressure on top of the piston is
equalized to that on the bottom, inlet
pressure, through the bleed hole and
the valve is closed due to the weight
of the piston in combination with the
closing spring. When the ‘S’ solenoid
is energized it allows the valve to
regulate. When the ‘B’ solenoid is
energized it overrides the ‘S’ feature
and the valve will is fully open.
Note: for more details on the
principles of operation for the ‘B’ and
‘S’ features see the previous single
operations.
A4WOK and A4WOBK Principle of
Operation
e A4WOK and A4WOBK operate in
the same manner as the A4WO and
A4WOB. ese regulators are factory
set for a given set pressure. e seal
cap is wired to the bonnet cap screw
and the wires are sealed with a lead
seal. e relief pressure setting is
stamped on the seal.
Note: if the lead seal is removed from
the ‘K’ featured valves prior to one
year of installation the warranty is
voided.
A4WOE and A4WOES Principles of
Operation
e A4WOE and A4WOES version
of the outlet regulator has a remote
sensing connection, which allows A4WO Manual Opening Stem Cross Section
Installation
All regulators are packed for a
maximum protection. Unpack
carefully. Check the carton to make
sure all items are unpacked. Save the
Passage Description
TOutlet Pressure
MManual Opening Stem
e small valve stem is located on the
side of the port plate as shown in the
A4WO manual opening stem cross-
section diagram. Using a screw driver,
turn the CCW to manually open the
valve. Turn the stem CW to put the
valve back into automatic operation.
ere must be at least a 2 psi pressure
drop across the valve to completely
open the valve. If there is less than
a 2 psi pressure dierence available
the valve will be partially open and at
some point less than 2 psi will close.
ere is still a leak path between the
valve inlet and outlet through the
manual opening valve for pump down
purposes.
T
M
Manual
Bypass
Stem
Manual Opening
Stem in Closed
Position:
Manual Opening
Stem in Open
Position:
T
M
Manual
Bypass
Stem
control of downstream pressure at a
point remote from the regulator outlet.
e port plate gasket (#35) has no
hole, thus blocking ow of upstream
pressure to the under side of the
diaphragm. e sensing pressure from
the desired control point, downstream
of the regulator, is connected to the
gauge port (#26). us the regulator
will control the pressure at the sensing
point. e regulator operation and
adjustment is the same as the A4WO
and A4WOS.

Page 6 / Bulletin 22-05 A
Adjustment
Adjustment of a regulator’s set
point requires that the pressure
being controlled be monitored by
an accurate pressure gauge. Before
making any adjustments, the seal
cap must be removed. In all cases
where the regulator is administering
Caution
Regulators with ‘B’ features can only
be adjusted with the pilot solenoid
de-energized. Regulators with the
‘S’ feature can only be adjusted with
the solenoid energized.
!
A4WO Disassembly
(See also Bulletin RSBCV)
All A4WO series regulators can be
disassembled and all serviceable
and moving parts replaced without
disturbing the piping, but of course,
disassembly will cause exposure of
some section of piping to atmosphere,
which should be addressed before
disassembly by evacuation and re-
claim of the refrigerant.
For the A4WO series outlet regulators,
the seal cap (#1) should be loosened
and the adjustment stem (#7)
backed out until no further spring
compression is felt. If it is known that
access to the range spring (#9) and
diaphragm (#14) is not required, the
sub-assembly from the port plate up
can remain intact and the regulator set
point can thus be preserved, avoiding
the need for gross adjustments when
the valve is put back in service. If
enclosed instruction for the installer
and eventual user.
Do not remove the protective
coverings from the inlet and outlet
of the regulator until the regulator
is ready to be installed. Protect the
inside of the regulator from dirt and
chips before and during installation.
e valves should not be disassembled
before welding. is grade of stainless
steel is a poor conductor of heat and
conventional weld processes (stick,
MIG, and TIG) do not create enough
heat that transfers to the valve’s
internal parts that could be aected.
Contractors need to follow a WPS
(Welding Procedure Specication) for
all welding. e procedure must be
qualied and welder doing the weld
qualied to perform that procedure.
For welding the stainless steel 304L
body to carbon steel pipe, E309L and
ER309L-15,-16, or -17 ller metal
is a common choice. Contractors
can develop their own standards
and have them qualied based on
the equipment they use and the
environment they may encounter.
e codes applicable to the welding
of socket weld valves require that the
pipe be inserted into the socket until
bottomed against the stop. e pipe is
then to be backed out approximately
1/16 of an inch before welding. Use
of welding rings is optional, but
recommended for butt weld valves.
Set Point
Range
Approx. Pressure
Change per Turn of
Adjusting Screw
Factory Set Point
(unless otherwise
specified)
V: 500mm hg to 8.3 bar
(20” hg to 120 psig)
0.7 bar
(10 psi)
2.8 bar
(40 psig)
D: 5.2 to 19.3 bar
(75 to 280 psig)
4.1 bar
(60 psi)
9.7 bar
(140 psig)
A4WO Pressure Setting Ranges
Suffix Description Typical Application
A4WOB Outlet Pressure Regulator
Electric Wide Open Crankcase Pressure Regulator
Receiver Pressure Control
Heat Reclaim
A4WOS Outlet Pressure Regulator
Electric Shut-Off
Suffix Table
ey help alignment, control gap for
full penetration welding, and reduce
welding debris entry.
Note: When welding carbon steel
and stainless steel the welded joint
should be painted to prevent galvanic
corrosion.
Socket welding where allowed is the
preferred connection. is connection
does help to reduce the amount of
welding debris in the piping system.
Welded valves may be installed in
horizontal or vertical pipelines. In a
horizontal pipeline the valve can be
mounted 90 degrees to either side
from the upright position. ese
valves can not exceed below the
3-O’clock and 9-O’clock positions. It is
important that the valves are installed
in the correct direction of ow,
because these regulators can control
ow in one only direction.
Before putting valves into service, all
pipe connections, valve seats, bonnet
seals, and stem seals should be tested
for leaks at pressure levels called for in
appropriate codes.
a pressure condition and a solenoid
feature is not overriding that function,
and the ow is in the normal direction,
turning the adjusting stem in the
(i.e. clockwise) direction will raise
the set point, and turning it (i.e.
counterclockwise) direction will lower
the set point. One complete turn of
the adjusting screw will change the set
point 0.69 bar (10 psig).
Depending on system responses, the
gauge may reect some delay before
change in set point actually results
in a change in the pressure being
maintained. is can also sometimes
be observed following the energization
or de-energization of the solenoid
features.
e pressure gauge can be connected
to the gauge port on the inlet side of
the regulator.
Always re-tighten the seal cap once
adjustments are complete.

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 Te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 o the
range spring as described above, and
the bonnet bolts (#4) removed. If a
solenoid feature 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 o, and will usually leave the
diaphragm resting on top of the gasket
(#15) and o-ring (#16). e bolts (#25)
retaining the lower sub-assembly can
now be removed. 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. 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. 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 lm of refrigerant oil, simply
wiped on with the ngers, All gaskets
and o-rings should be renewed, and
insertion and sealing will be facilitated
if a similar 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

A
A
A4WOB, A4WOS,
A4WOBS
Valves Only
Page 8 / Bulletin 22-05 A
1
3
2
4
5
7
9
8
6
11
13
15
10
12
14
18
16
19
20
21
22
23
24
25
26
27 29
31
28
32
30
34
33
23
48
47
46
45
44
35
36
37
38
39
40
41
42
43
A4WO Exploded Parts View (A4WOS shown)
Note: The port plate for a A4WO and A4WOE outlet pressure regulator does not
contain coil options and is a separate port plate as shown.
17
18A
49

Bulletin 22-05 A / Page 9
Item No. Kit Description
Port Size
20 mm
(3/4”)
25 mm
(1”)
32 mm
(1-1/4””)
40 mm
(1-1/2”)
50 mm
(2”)
1, 2 Seal Cap 208757 208757 208757 208757 208757
2, 3 , 5 - 13 Bonnet 208759 208759 208759 208759 208759
2, 5 - 13 Spring, Bonnet (Range V) 208760 208760 208760 208760 208760
2, 5 - 13 Spring, Bonnet (Range D) 208818 208818 208818 208818 208818
14 - 16 Diaphragm 208802 208802 208802 208802 208802
18 - 21 Pilot Plug (A4WO, A4WOK Only) 208765 208765 208765 208765 208765
17, 18A - 21 Pilot Plug (A4WOB, A4WOS,
A4WOBS Only) 208766 208766 208766 208766 208766
22 - 24 Seal Cap 208758 208758 208758 208758 208758
26 -27 Gage Plug (A4WO Only) 208808 208808 208808 208808 208808
28 - 31 Manual Opening Stem 208809 208809 208809 208809 208809
18 - 21, 26 - 34 Port Plate (A4WO, A4WOK Only) 208761 208761 208761 208761 208761
17, 18A - 23, 26,
28 - 35, 46 - 49 Port Plate (A4WOB, A4WOBK Only) 208762 208762 208762 208762 208762
17, 18A - 24, 26,
28 - 35, 46 - 49 Port Plate (A4WOS Only) 208763 208763 208763 208763 208763
17, 18A - 21, 26,
28 - 32, 33 - 35,
46 - 49
Port Plate (A4WOBS Only) 208764 208764 208764 208764 208764
18 - 21, 27 - 34 Port Plate (A4WOE Only) 208943 208943 208943 208943 208943
17, 18A - 24,
28 - 35, 46 - 49 Port Plate (A4WOES Only) 208944 208944 208944 208944 208944
35 - 42 Piston 208778 208779 208780 208781 208782
35 - 39 Spring, Piston 208795 208796 208797 208798 208799
35 - 39, 41 - 42 Wear Seal, Piston 208819 208819 208820 208821 208821
2, 5 - 6, 13, 15 - 16, 20
35 - 38, 41-42 Gasket / O-Ring (A4WO, A4WOK Only) 208838 208839 208840 208841 208842
2, 5 - 6, 13, 15 - 16,
20, 23, 28, 35 - 38,
41-42
Gasket / O-Ring (A4WOB, A4WOS,
A4WOBS, A4WOBK Only) 208843 208844 208845 208846 208847
4 Bolt, Bonnet 208800 208800 208800 208800 208800
25 Bolt, Port Plate 208801 208801 208801 208801 208801
23, 33, 46 - 48 * Solenoid Pseudo (“S” or “B” Only) 208940 208940 208940 208940 208940
44 - 45 Coil, 120/60 or 110/50 18.5 Watt Leaded 204843 204843 204843 204843 204843
44 - 45 Coil, 240/60 or 220/50 18.5 Watt Leaded 204844 204844 204844 204844 204844
44 - 45 Coil, 208/60 18.5 Watt Leaded 204845 204845 204845 204845 204845
44 - 45 Coil, 240/50 18.5 Watt Leaded 204846 204846 204846 204846 204846
44 - 45 Coil, 24/60 18.5 Watt Leaded 206244 206244 206244 206244 206244
* If repairing a A4WOBS valve two kits must be ordered.
A4WO, A4WOB, A4WOS, & A4WOBS Repair Kits
Item No. Description Material Qty
44 Coil Clip S.S. 1
45 Coil (“S” & “B” Only) ------- 1
46 Solenoid Pseudo Assembly (“S” &
“B” Only) S.S. 1
47 Armature, Coil (“S” & “B” Only) S.S. 1
48 Ring, Seal Teon (PTFE) 1
49 Spring, Coil (“S” & “B” Only) S.S. 1
A4WO, A4WOB, A4WOS, & A4WOBS Parts List (continued)

12.334
8.938
1.938
3.540
.719
12.334
8.938
1.938
3.540
.551
Page 10 / Bulletin 22-05 A
A
B
C
D
E
Dimension
Port Size
20 - 25 mm
(3/4” - 1”)
32 mm
(1-1/4”)
40 - 50 mm
(1-1/2” - 2”)
A144.5 mm
(5.69”)
176.3 mm
(6.94”)
227.1 mm
(8.94”)
B11.2 mm
(0.44”)
13.7 mm
(0.54”)
14.0 mm
(0.55”)
C90.0 mm
(3.54”)
90.0 mm
(3.54”)
90.0 mm
(3.54”)
D266.7 mm
(10.5”)
299.5 mm
(11.79”)
312.7 mm
(12.31”)
E41.4 mm
(1.63”)
53.1 mm
(2.09”)
49.3 mm
(1.94”)
A4WO Butt Weld (BW) Dimensions
A
B
C
D
E
Dimension
Port Size
20 - 25 mm
(3/4” - 1”)
32 mm
(1-1/4”)
40 - 50 mm
(1-1/2” - 2”)
A144.5 mm
(5.69”)
176.3 mm
(6.94”)
227.1 mm
(8.94”)
B12.7 mm
(0.50”)
12.7 mm
(0.50”)
16.0 mm
(0.63”)
C90.0 mm
(3.54”)
90.0 mm
(3.54”)
90.0 mm
(3.54”)
D266.7 mm
(10.5”)
299.5 mm
(11.79”)
312.7 mm
(12.31”)
E41.4 mm
(1.63”)
53.1 mm
(2.09”)
49.3 mm
(1.94”)
A4WO Socket Weld (SW) Dimensions

Bulletin 22-05 A / Page 11
corresponding gaskets be aligned
with the appropriate location. Ensure
that all access ttings, solenoid
features, and bypass plug are sealed
when re-installing the corresponding
parts. Prior to installing the port plate
inspect the piston, using your hand,
by pulling up and pushing down. e
piston should move freely, without
dragging or hesitation. Adjust all
torques to the values indicated by
torque requirement table.
Tighten all bolts equally to draw the
assembly together evenly, to ensure
properly sealing of all joints. Replace
all seal caps as applicable. When
re-adjusting following servicing,
prevent excessive pressures by starting
with the adjustment stem at low
spring compression until the system
approaches the desired operating
pressures, then re-set as per “AD-
JUSTMENT”, above.
A4WOK and A4WOBK Disassembly
For disassembly and assembly
follow the general procedure
and the procedure for the A4WO.
is regulator has a sealed wire
connection to keep the seal cap from
being removed. is wire must be
removed before the regulator can be
disassembled.
Note: breaking or removal of the seal
voids any Refrigerating Specialties
Division factory responsibility for the
regulator pressure set-point.
Electrical
e Refrigerating Specialties Division
molded water resistant Class “H”
solenoid coil is designed for long
life and powerful opening force. e
standard coil housing meets NEMA
3R and 4 requirements. is sealed
construction can withstand direct
contact with moisture and ice. By
denition, Class “H” coil construction
will permit coil temperatures, as
measured by resistance method,
as high as 185°C. (366°F.) Final coil
temperatures are a function of both
uid and ambient temperatures. e
higher uid temperatures require
lower ambient temperatures for the
maximum coil temperature not to
be exceeded. Conversely, low uid
temperatures permit higher ambient
temperatures.
A solenoid coil should never be
energized except when mounted on its
corresponding solenoid tube.
e molded Class “H” coil is available
from stock with most standard
voltages. However, coils are available
for other voltages and frequencies, as
well as for direct current.
e solenoid coil must be connected
to electrical lines with volts and
Hertz same as stamped on coil. e
supply circuits must be properly
sized to give adequate voltage at the
coil leads even when other electrical
equipment is operating. e coil is
designed to operate with line voltage
from 85% to 110% of rated coil voltage.
Operating with a line voltage above
or below these limits may result
in coil burn-out. Also, operating
with line voltage below the limit
will denitely result in lowering the
valve’s maximum opening pressure
dierential. Power consumption
during normal operation will be 18.2
watts or less.
Caution
All personnel working on valves
must be qualied to work on
refrigeration systems. If there
are any question, contact
Refrigerating Specialties before
proceeding with the work.
Before doing any service work,
always be sure to disconnect
the power and isolate the valve.
Failure to do so will result in
venting of ammonia.
!
Valve
Port Size
20 mm
(3/4”)
25 mm
(1”)
32 mm
(1-1/4””)
40 mm
(1-1/2”)
50 mm
(2”)
A4WO,
A4AWOE,
A4WOK
5.0 kg
(11 lbs)
5.0 kg
(11 lbs)
6.1 kg
(13.3 lbs)
6.1 kg
(13.3 lbs)
6.8 kg
(15.1 lbs)
A4WOB,
A4WOBK
5.4 kg
(11.8 lbs)
5.4 kg
(11.8 lbs)
6.4 kg
(14.2 lbs)
6.4 kg
(14.2 lbs)
7.4 kg
(16.2 lbs)
A4WOS,
A4WOES
5.4 kg
(11.8 lbs)
5.4 kg
(11.8 lbs)
6.4 kg
(14.2 lbs)
6.4 kg
(14.2 lbs)
7.4 kg
(16.2 lbs)
A4WOBS 5.7 kg
(12.5 lbs)
5.7 kg
(12.5 lbs)
6.8 kg
(15.0 lbs)
6.8 kg
(15.0 lbs)
7.8 kg
(17.2 lbs)
Socket Weld (SW) and Butt Weld (BW) Valve Weights

© 2008 Parker Hannin Corporation
ISO 9001 CERTIFIED
312069 ECN: 9078 06/11/09
Safe Operation (See Bulletin RSBCV)
People doing any work on a refrigeration system must be
qualied and completely familiar with the system and the
Refrigerating Specialties Division valves involved, or all other
precautions will be meaningless. is includes reading and
understanding pertinent Refrigerating Specialties Division
Product Bulletins and Safety Bulletin RSB prior to installation
or servicing work.
Where cold refrigerant liquid lines are used, it is necessary
that certain precautions be taken to avoid damage which
could result from liquid expansion. Temperature increase in a
piping section full of solid liquid will cause high pressure due
to the expanding liquid which can possibly rupture a gasket,
pipe or valve. All hand valves isolating such sections should
be marked, warning against accidental closing, and must
not be closed until the liquid is removed. Check valves must
never be installed upstream of solenoid valves, or regulators
with electric shut-o, nor should hand valves upstream of
solenoid valves or downstream of check valves be closed until
the liquid has been removed.
It is advisable to properly install relief devices in any section
where liquid expansion could take place. Avoid all piping
or control arrangements which might produce thermal or
pressure shock.
For the protection of people and products, all refrigerant
must be removed from the section to be worked on before a
valve, strainer, or other device is opened or removed. Flanges
with ODS connections are not suitable for ammonia service.
Warranty
All Refrigerating Specialties products are under warranty
against defects in workmanship and materials for a period of
one year from date of shipment from factory. This warranty
is in force only when products are properly installed, field
assembled, maintained, and operated in use and service as
specifically stated in Refrigerating Specialties Catalogs or
Bulletins for normal refrigeration applications, unless other-
wise approved in writing by the Refrigerating Specialties
Division. Defective products, or parts thereof returned to the
factory with transportation charges prepaid and found to be
defective by factory inspection, will be replaced or repaired at
Refrigerating Specialties option, free of charge, F.O.B. factory.
Warranty does not cover products which have been altered,
or repaired in the field, damaged in transit, or have suffered
accidents, misuse, or abuse. Products disabled by dirt or other
foreign substances will not be considered defective.
e express warranty set forth above constitutes the only
warranty applicable to Refrigerating Specialties products, and
is in lieu of all other warranties, expressed or implied, written
including any warranty of merchantability, or tness for a
particular purpose. In no event is Refrigerating Specialties
responsible for any consequential damages of any nature what-
soever. No employee, agent, dealer or other person is authorized
to give any warranties on behalf of Refrigerating Specialties, nor
to assume, for Refrigerating Specialties, any other liability in
connection with any of its products.
Symptom Probable Cause Correction
Failure to open,
close, or regulate
Piston jammed due to excessive dirt Flush clearance space between piston and
cartridge bore with refrigeration oil solvent
Valve Manually Open Close manual bypass stem by tuning clockwise
Adjusting stem improperly positioned:
a. Turned in too far. Does not open (inlet regulator)
b. Not turned far enough. Does not close (inlet
regulator). Does not open (outlet regulator)
Position adjusting stem properly
Passage “N” clogged Clean passage “N”
Pilot seat dirty or eroded Clean and smooth pilot seat. If diaphragm is
removed, replace with new gasket and O-Ring
Regulator installed backwards Re-install regulator in proper position
System Control
cannot be
maintained -
unstable valve
operation
Improper regulator selection:
a. Actual load is mush lower than regulator capacity
b. Actual pressure drop across valve higher than
originally intended
c. Combination of a and b
Replace cartridge with one of suitable size
A4WO Service Pointers
Location Description (SAE) Torque mkg (Ft-Lbs)
Bonnet Screws M6 x 18 MM (7)
Port Plate Screws M10 x 45 MM (35)
Bonnet Seal Cap —Snug
Solenoid Pseudo
Assembly —Snug
Gages Port Plug 1/4” NPT 1.4 (10)
Pilot Plug —Snug
A4WO Torque Requirement Table