Parker S4A-DN Installation And Service Information

SOLENOID VALVE
Type S4A-DN
Port Size 20-100mm (3/4"-4")
FOR AMMONIA, R12, R22, R502
AND OTHER COMMON REFRIGERANTS
FEATURES
• Standard Coil Housing Meets NEMA 3R and
NEMA 4-Rain Tight
• Coil Housing Surpasses NEMA Salt Spray Test
• Plunger-Needle Assembly Same for
S4A,S5A,S6N,S6A,S8F
• Molded Class "B" Coil Construction
• Same Coil Fits Most Refrigerating Specialties
Solenoid Valves
• Pilot Light Available
• Stainless Steel Needle
• Manual Opening Stem
• Design Pressure (PS): 28 bar (406 PSIG)
• Complies with Pressure Equipment Directive 97/23/EC
Description
This heavy duty solenoid valve is suitable for Ammonia, R-12, R-22,
and R-502, other refrigerants, certain oils and other fluids approved
for use in refrigeration. The S4A is a pilot operated, semi-steel bodied
valve. The valve may be opened by means of the manual opening
stem for servicing or in case of electrical power failure.
The Type S4A Solenoid Valve is furnished with FPT Internal NPT (U.S.
Standard Taper Pipe Thread), Socket Weld, Weld Neck or ODS (solders
over copper tubing of given diameter) connections. The valve may be
easily removed from between the flanges for servicing.
Fig. 1
Refrigerating Specialties Division
310226
BULLETIN DN30-94B
Type S4A-DN
January 2007
Installation and Service Information
It is advisable to install a strainer upstream of each valve to prevent
entrance of foreign material into the valve and the rest of the system.
Refrigerating Specialties strainers are available to close-couple to valve
inlets.
Purpose
Type S4A is a spring closing valve, suitable for use in refrigerant liquid,
hot gas or suction lines in a temperature range of -50° to 105°C (-60°
to 220°F).
Principles of Operation
The Type S4A is a pilot operated solenoid. The valve in its closed
position, with the solenoid coil de-energized and the plunger needle
and main port plug in the seated position, is shown in Figure 1.
Electrical energization of the solenoid coil forms a magnetic field,
pulling up the plunger which strikes the needle, lifting it off its seat.
Upward motion of the needle permits entrance of the fluid from the
valve inlet M through Port N and down through the pilot port to the top
of the power piston. This forces the piston downward and pushes the
main port plug open, thereby permitting flow of the refrigerant through
the valve. The closing spring meanwhile is held in a compressed
position.
De-energization of the solenoid coil permits the spring-assisted needle
to drop back into its seat, stopping the flow through the pilot port.
Bleed-off, through the bleed hole in the piston, decreases the pressure
above the piston and allows the closing spring to force the main port
plug upward into a closed position to stop the flow. The pressure
difference across the valve, acting upon the area of the valve seat,
plus the force of the closing spring, holds the main port plug in a
tightly closed position.
Manual Opening Stem
The manual opening stem on the Type S4A is for the purpose of
opening the valve without energizing the solenoid coil. Refer to the
applicable exploded view and parts list for location of the stem and
other related parts. For access to stem the seal cap on the bottom of
the valve must be removed. This must be done with caution as
refrigerant may have been trapped inside the seal cap. To open the
valve manually, turn the stem counterclockwise as far as it goes. To
reset for automatic operation turn the stem clockwise until only the
flats on the end of the stem protrude from the packing nut.
1
I S O 9 0 0 1 C E R T I F I E D