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Refrigerating Specialties Division
SOLENOID VALVE
Type S5A (S5AE)
Port Size 32-75mm (1¼”-3”)
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
• Replaceable Piston Plug Assembly
• Molded Class “B” Coil Construction
• Pilot Light Available
• Stainless Steel Needle
• Manual Opening Stem
• MOPD 20.7 bar (300 PSIG)
• 27.6 bar (400 PSIG) maximum rated pressure (MRP)
BULLETIN 30-93E
Type S5A
May 2005
Installation, Service and Parts Information
050261
Description
This heavy duty solenoid valve is suitable for Ammonia, R-12, R-22,
and R-502, other refrigerants, certain oils and other fl uids approved
for use in refrigeration. The S5A is a pilot operated semi-steel bod ied
valve. The valve may be opened by means of the manual open ing stem
for servicing or in case of electrical power failure.
The Type S5A 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 fl anges for servicing.
It is advisable to install a strainer upstream of each valve to prevent
entrance of foreign material into the valves and the rest of the sys tem.
Refrigerating Specialties strainers are available to close-couple to
valve inlets.
Purpose
Type S5A is recommended for use in refrigerant liquid or suction lines.
It is not recommended for hot gas lines and other applications where
high pressure drops will exist when the valve is open.
Principles of Operation
The Type S5A is a pilot operated solenoid. Operation is as follows: The
valve, in its closed position, with the solenoid coil de-energized and the
plunger-needle in its seated position, is shown in Figure 1. Before the
valve is opened, the pressure above the piston-main valve assembly is
equalized through the bleed hole and is the same as the inlet pressure.
Electrical energization of the solenoid coil forms a magnetic fi eld,
pulling up the plunger which strikes the nee dle, lifting it off its seat. This
permits the refrigerant trapped above the piston-main valve assembly
to fl ow through the pilot and through Port N to the downstream side of
the valve. The pressure above the piston-main valve is reduced and the
higher inlet pres sure against the underside of the piston-main valve
assembly forces it upward. This puts the valve in the open position
permitting fl ow of the refrigerant. The minimum pressure drop to hold
the valve wide open is 0.07 bar (1.0 PSI).
De-energization of the solenoid coil permits the spring-assisted needle
to drop back into its seat, stopping the fl ow through the pilot port,
and the pressure above and below the piston-main valve is equalized.
The weight of the piston-main valve then causes it to drop to its seat,
stopping the fl ow of the refrigerant. The pressure difference across
the valve, acting upon the area of the valve seat, holds the piston-main
valve in a tightly closed position.
Manual Opening Stem (See Fig. 1)
The manual opening stem on the Type S5A is for the purpose of opening
the valve without energizing the solenoid coil. For access to the stem
the seal cap on the bottom of the valve must be re moved. This must be
done with caution as refrigerant may have been trapped inside the seal
cap. Manual opening is accomplished by turning the stem clockwise
until only the fl ats on the end of the stem protrude from the packing
nut. To reset for automatic opera tion turn the stem counterclockwise
as far as it goes.
Fig 1
I S O 9 0 0 1 - 2 0 0 0 C E R T I F I E D
