Parker S5A-DN Installation And Service Information

SOLENOID VALVE
Type S5A-DN (S5AE-DN)
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
• 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 S5A 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 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 flanges for servicing.
Fig. 1
Refrigerating Specialties Division
310225
BULLETIN DN30-93B
Type S5A-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 valves and the rest of the system.
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 field, pulling up the plunger which strikes the needle, lifting
it off its seat. This permits the refrigerant trapped above the piston-main
valve assembly to flow 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 pressure against the underside
of the piston-main valve assembly forces it upward. This puts the valve
in the open position permitting flow 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 flow 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 flow 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 removed.
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 flats on the end of the stem protrude
from the packing nut. To reset for automatic operation turn the stem
counterclockwise as far as it goes.
1
I S O 9 0 0 1 C E R T I F I E D