Parker A4W Series 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 22-00 A
Inlet Pressure Regulator
Type: A4W, A4WB, A4WS, A4WBS, A4WK, A4WBK,
A4WE
Size: 20 - 50 mm (3⁄4” to 2”)
Design Pressure Rating: 32 bar (464 psig)
Purpose:
The A4W inlet pressure regulators
modulate the ow of refrigerant
gas or liquid to maintain a
constant upstream 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 A4Ws 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
A4WS
A4WS
A4W
A4WB
A4WBS
Patent Pending

Page 2 / Bulletin 22-00 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
A4W Inlet Pressure Regulator Cross Section (1-1/2” Valve Body Shown)
Seal
Cap
Bonnet
Assembly
Diaphragm
Inlet 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
Manual
Opening
Stem
Description
All A4W inlet 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 A4W 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 22-00 A / Page 3
A4W Principle of Operation
e inlet pressure enters the valve
lling the areas inside the piston
and inlet. e pressure above the
piston prevents the piston from
moving upward. Inlet pressure travels
through passage (N), shown in the
A4W principle of operation cross-
section diagram, lling the chamber
underneath the diaphragm. When the
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.
Note: Upstream pressure,
communicated through passage (N),
is “sealed” under the diaphragm.
e tight seal of the pilot plug and
pilot plug piston o-ring maintains
the inlet pressure as an independent
pressure source. e upstream
pressure is not used as a pilot force
to move the piston. It simply works
against the force exerted by the range
spring which ultimately moves the
diaphragm. is greatly enhances
the ability of these regulators to
operate despite the presence of system
impurities.
e upward movement of the pilot
plug piston causes the pilot plug
piston seat to unseat, allowing the
pressure on top of the piston to vent
through the pilot plug, passage (P),
to the downstream side of the valve,
passage (T). e lowering of the
pressure above the piston combined
with a higher inlet pressure causes it
to move upward, and the valve begins
to regulate upstream pressure at its
set point. As the valve regulates, a
bleed hole in the piston allows for
the continuous equalization of inlet
pressure to the top of the piston. A
piston seal ring ensures that this bleed
hole is the sole source of equalization.
e pressure on top of the piston
varies with the position of the pilot
plug piston and the pressure drop
across the valve. As the pilot plug
A4W Principle of Operation Cross Section
A4WB Principle of Operation Cross Section (‘B’ Coil De-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
A4W Port Plate Passage Table
N
T
PPilot Plug
Piston
Seat
Pilot Plug
Piston Seal
O-Ring
Diaphragm
Pilot
Spring
Manual
Bypass
Stem
Pilot Plug
Piston
H
N
P
T
B
M
N
Electric
Wide
Open
Manual
Bypass
Stem
T
P
Seal Cap

Page 4 / Bulletin 22-00 A
piston changes position, the pressure
on top of the piston changes also.
erefore, a decrease in upstream
pressure will result in the range spring
pushing both the diaphragm and pilot
plug piston downward. Increasing
pressure on top of the piston causing
the valve to close, thereby decreasing
ow through the main valve as the
piston begins to regulate towards
a closed position. Conversely, an
increase in upstream pressure will
move the diaphragm up along with
the pilot plug. Resulting in a lower
pressure on top of the piston and
causing the valve to opening.
Note: In the A4W port plate there are
two channels illustrated in the inlet
side cross sectional drawing. e
internal channel running horizontally
from the gauge port, passage (H),
to the pilot plug is used for an R/S
outlet regulator, A4WO, variation and
is not required for a standard A4W
inlet regulator. A plug is installed at
the factory to prevent any pilot ow
through this channel.
A4WB Principle of Operation
e port plate for the A4WB is a
slightly dierent construction, shown
in the A4WB principle of operation
cross-section diagram, than the
standard A4W, but the regulating
portion of the valve works in the same
manner as described in the A4W
principles of operation.
Note: e passages in the A4WB port
plate are not in the same cross section
as shown in the diagram. e upper
half of passage (N), 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
A4WS Principle of Operation Cross Section (‘S’ Coil Energized)
A4WBS Principle of Operation Cross Section (‘B’ Coil De- Energized
and ‘S’ Coil Energized)
Electric
Shut-Off
N
P
T
B
M
N
Electric
Wide
Open
Manual
Bypass
Stem
T
P
N
P
T
B
M
N
Electric
Shut-Off
Manual
Bypass
Stem
T
P
Seal Cap
Passage Description
N Inlet Pressure
P Piston Pressure, Top
TOutlet Pressure
BElectric Wide Open Bypass
SElectric Shut-Off
MManual Opening Stem
A4W Port Plate Passage Table

Bulletin 22-00 A / Page 5
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.
A4WS Principle of Operation
e port plate for the A4WS is the
same port plate used for the A4WB.
e only dierence is the seal cap
and coil assembly is located in the
opposite location, as shown in the
A4WS principle of operation cross-
section. e regulating portion of the
valve works in the same manner as the
A4W principle of operation.
e ‘S’ feature, electric shut o, when
energized will cause the solenoid plug
to lift and allow the valve to regulate.
e pressure on top of the piston is
released through passage (P), the pilot
plug, 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.
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
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.
Simply energize the ‘S’ feature on the
valve to regulate.
A4WBS Principle of Operation
e port plate for the A4WBS is the
same port plate used for the A4WB
and A4WS. e regulating portion of
the valve works in the same manner
as the A4WS described above. e
A4WBS 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 be fully open.
Note: for more details on the
principles of operation for the ‘B’ and
‘S’ features see the previous single
operations.
A4WK and A4WBK Principle of
Operation
e A4WK and A4WBk operate in the
same manner as the A4W and A4WB.
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.
A4W Manual Opening Stem Cross Section
T
M
Manual
Bypass
Stem
T
M
Manual
Bypass
Stem
Manual Opening
Stem in Closed
Position:
Manual Opening
Stem in Open
Position:
Passage Description
TOutlet Pressure
MManual Opening Stem
Note: If the lead seal is removed from
the ‘K’ featured valves prior to one
year of installation the warranty is
voided.
A4WE Principle of Operation
e A4WE version of the inlet
regulator has a remote sensing
connection, which allows control of
upstream pressure at a point remote
from the regulator inlet. 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, upstream 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 A4W.

Page 6 / Bulletin 22-00 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
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.
Installation
All regulators are packed for a
maximum protection. Unpack
carefully. Check the carton to make
sure all items are unpacked. Save the
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.
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.
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)
A4W Pressure Setting Ranges
Suffix Description Typical Application
A4WB Outlet Pressure Regulator
Electric Wide Open
Evaporator Pressure Regulator
Defrost Relief Regulator
Head Pressure Control
Heat Reclaim
Back Pressure Regulator
A4WS Outlet Pressure Regulator
Electric Shut-Off
Suffix Table
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.
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.
e small valve stem is located on the
side of the port plate as shown in the
A4W 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.

Bulletin 22-00 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
A-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 x 0.062 Neoprene 1
18 Plug, Pilot 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 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
A4W, A4WB, A4WS, A4WBS Parts List
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.
!
A4W Disassembly
(See also Bulletin RSBCV)
All A4W 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 A4W series inlet 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 access to the
pilot assembly (#17 – 21) on an A4W
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

Page 8 / Bulletin 22-00 A
1
3
2
4
5
7
9
8
6
11
13
15
10
12
14
17
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
A4W Exploded Parts View (A4WB shown)
Note: The port plate for a A4W and A4WE inlet pressure regulator does not contain
coil options and is a separate port plate as shown.
49

Bulletin 22-00 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
17 - 21 Pilot Plug 208767 208767 208767 208767 208767
22 - 24 Seal Cap 208758 208758 208758 208758 208758
26 -27 Gauge Plug 208808 208808 208808 208808 208808
28 - 31 Manual Opening Stem 208809 208809 208809 208809 208809
16 - 21, 26 - 34 Port Plate (A4W, A4WK Only) 208814 208814 208814 208814 208814
16 - 23,
26 - 35, 46 - 49 Port Plate (A4WB, A4WBK Only) 208815 208815 208815 208815 208815
16 - 24,
26 - 35, 46 - 49 Port Plate (A4WS Only) 208816 208816 208816 208816 208816
16 - 21, 26 - 32, 33,
34- 35, 46 - 49 Port Plate (A4WBS Only) 208817 208817 208817 208817 208817
16 - 21,
27 - 32, 34- 35 Port Plate (A4WE Only) 208945 208945 208945 208945 208945
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, 14, 16 - 17,
20, 35 - 38, 41-42 Gasket / O-Ring (A4W, A4WK Only) 208823 208803 208804 208805 208806
2, 5 - 6, 13, 14,
16 - 17, 20, 23, 28,
35 - 38, 41-42
Gasket / O-Ring (A4WB, A4WS, A4WBS,
A4WBK Only) 208824 208824 208807 208812 208813
4 Bolt, Bonnet 208800 208800 208800 208800 208800
25 Bolt, Port Plate 208801 208801 208801 208801 208801
33, 46 - 49 * 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
----- Gauge Kit, S.S. 208938 208938 208938 208938 208938
----- Gauge Kit, Plated 208939 208939 208939 208939 208939
* If repairing a A4WBS valve two kits must be ordered.
A4W, A4WB, A4WS, & A4WBS Repair Kits
Item No. Description Material Qty
44 Clip, Coil 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
A4W, A4WB, A4WS, & A4WBS Parts List (continued)

Page 10 / Bulletin 22-00 A
12.334
8.938
1.938
3.540
.551
A
B
C
D
E
12.334
8.938
1.938
3.540
.719
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”)
A4W Butt Weld (BW) Dimensions
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”)
A4W Socket Weld (SW) Dimensions

Bulletin 22-00 A / Page 11
Valve
Port Size
20 mm
(3/4”)
25 mm
(1”)
32 mm
(1-1/4””)
40 mm
(1-1/2”)
50 mm
(2”)
A4W, A4WK, A4WE 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)
A4WB, A4WBK 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)
A4WS 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)
A4WBS 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
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 def-
inition, 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.
!
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.
A4WK and A4WBK Disassembly
For disassembly and assembly
follow the general procedure and the
procedure for the A4W. 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.
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
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.

© 2008 Parker Hannin Corporation
ISO 9001 CERTIFIED
312068 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
A4W 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
Gauge Port Plug 1/4” NPT 1.4 (10)
Pilot Plug 7/16-20 Snug
A4W Torque Requirement Table