Installation; Disassembly And Assembly - Parker A4W Series Installation And Service Information

Fig. 6 – A4WR
Adjustment
See the appropriate bulletin as listed above under "Principles of
Operation".

Installation

It is necessary that all installation personnel read and become familiar
with the Refrigerating Specialties Division's Refrigeration Safety Bulletin
(RSBCV) before installing any valves.
All valves are packed for the maximum protection during storage and
shipment Read the literature packed with the valve and save it for reference
after installation.
Do not remove the protective covers from the inlet and outlet of the valve
until ready to install, as they protect the interior from dirt and other foreign
matter.
Select a location for installation where the valve will be easily accessible
for adjustment and maintenance and where a pressure gauge installed on
the regulator can be seen. Avoid locations where the valve may be damaged
by personnel, traffic, material handling or other equipment.
Before installing the valve, check to see that all chips, scale, dirt, moisture
and other foreign material are removed from the connecting pipes. Be
sure the arrow on the A4W valve body is pointing in the direction of fluid
flow for the regulator to function properly. Backward flow through the
regulator is uncontrolled and will vary with the reverse pressure drop
encountered. The regulator is NOT a check valve. Remove the protective
covers from the valve. It is not necessary to disassemble or to manually
open the valve before welding in place.
The A4W family of regulators will give optimum performance if mounted in
a horizontal line in a vertical position with the Manual Opening Stem on
the top. This is particularly true for regulators with an electrical feature,
such as the "B", "S" or "D" variations. Where other positions are desired,
the factory should be consulted; please give valve type, application and
piping details.
After installation, check the valve and the welded joints for external
leaks with refrigerant or other appropriate gas before putting the system
into operation
If pilot solenoid valves are a part of the regulator, connect the solenoid
lead wires to an electrical supply source the same as indicated on the
valve coil. The power source must be capable of supplying full, constant
voltage. The wires to which the solenoid leads are connected must be of
the proper gauge.
When it is necessary to insulate the regulator (and companion strainer),
the insulation should be installed to allow access to the regulator (and
companion strainer) for adjustment and maintenance. Do not insulate a
solenoid coil and coil housing. Proper indicating gauges should be
installed to be easily visible to the operating engineer for system checking
and adjusting purposes.
Refrigerating Specialties Division
Electrical (For A4WS, A4WB and A4WD)
The Refrigerating Specialties Division molded, water resistant Class "B"
solenoid coil is designed for long life and powerful opening force. The
standard coil housing meets NEMA 3R and 4 requirements. This sealed
construction can withstand direct contact with moisture and ice. The coil
housing far exceeds the requirements of NEMA Standard ICS, 1-110.57
salt spray test for rust resistance.
By definition, Class "B" coil construction will permit coil internal
temperatures, as measured by the resistance method, as high as 130
deg. C (266 deg. F). Final coil temperatures are a function of both fluid
and ambient temperatures. The higher fluid temperatures require lower
ambient temperatures so the maximum coil temperature is not exceeded.
Conversely, low fluid temperatures permit higher ambient
temperatures.
The molded Class "B" coil is available, from Refrigerating Specialties Div.
stock, with most standard voltages. However, coils are available for other
voltages and frequencies, as well as for direct current. Coils are also
available as transformer type with a 6 volt secondary winding for use with
the Refrigerating Specialties Division Pilot Light Assembly. (See current
copy of Bulletin 60-10, "Pilot Light Assembly and Solenoid Transformer
Coil".)
The solenoid coil must be connected to electrical lines with volts and
Hertz the same as stamped on the coil. The supply circuits must be properly
sized to give adequate voltage at the coil leads even when other electrical
equipment is operating. The 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 voltages below the limit will definitely result in lowering the valve's
maximum opening pressure differential. Power consumption during normal
operation will be 33 watts or less. Note that no coil should ever be energized
when it is not securely mounted on the solenoid tube.
Inrush and running current is listed below:
Standard Coil
Volts/Hertz
120/60 (Blue leads)
208/60 (Blue & Red leads
240/60 (Red leads)
440/60 (Yellow & Red leads)
115/50 (Yellow & Blue leads)
230/50 (Yellow leads)
Other
(On transformer coil, the 6 volt leads are always black.)

Disassembly and Assembly

General Procedure (See Figs. 8, 9, and 10)
Before disassembling any A4W type regulator, read the information in
this bulletin and Bulletin RSBCV (Safety Procedures for Refrigerating
Specialties Division Refrigeration Control Valves).
Before a regulator is disassembled in the line, make sure that all refrigerant
has been removed from the regulator, including the Bonnet (where
applicable), the close coupled Strainer (if used) and the adjacent pipes at
the inlet and outlet of the valve. The regulator must be isolated from the
rest of the system in a safe manner. When pumping down to remove the
refrigerant, the Manual Opening Stem 11 must be turned in (clockwise)
to make sure that the valve is open.
All service or disassembly work is done from only the top side of all A4W
Regulators. The construction of the regulator and the method of
disassembly are relatively simple, but some procedures must be followed
to avoid damage or injury. The following describes the procedure for the
basic A4W: special instructions for other types are included in the
appropriate sections.
See Fig. 9 for S6A Pilot Solenoid Valve and Fig. 10 for A2D Pilot Regulator
Valve. See also Bulletin DN23-06 for additional information about the
S6A Pilot Solenoid and the A2D Pilot Regulator Valves.
Disassembly (See Figs. 8 , 9 and 10)
Take care when removing Seal Caps 15 and 57 in case some refrigerant
may be trapped inside. Back the Adjusting Stem 52 all of the way out
(counterclockwise) to remove any pressure from the Range Spring 49,
5
Inrush Running Fuse
Current Current Size
(Amps) (Amps) (Amps)
1.18 0.46 1
0.63 0.26 1
0.60 0.23 1
0.39 0.13 1
1.22 0.21 1
0.65 0.26 1
(Contact Factory)