2-1/2 S9A 1/2S 3SW

The S9A and S9W are heavy-duty gas powered valves suitable for ammonia and other refrigerants, certain oils and other fluids approved for use in refrigeration. They are pilot operated semi-steel bodied valves. The valves may be opened by means of the manual opening stem for servicing or in case of electrical power failure. The Type S9A and S9W are pilot operated valves but uses an external source of higher pressure gas to operate the valve, and, therefore requires no minimum pressure drop to open. The external gas pressure for the Type S9A must be at least 0.69 bar (10 psi), and 0.71 bar (10 psi) for the S9W, above valve internal upstream pressure for positive opening. This valve is normally closed. They are two-position valves using condenser gas pressure acting upon a piston for opening, and a strong spring for closing. A lapped seat at the top of the piston prevents the condenser gas from leaking around the piston to the compressor suction side of the valve. A twin Pilot Solenoid Valve assembly serves to admit condenser gas pressure to the piston for opening and to bleed this gas pressure to the suction line for valve closing. A single-pole, double throw thermostat or relay may be used to control these two Pilot Solenoid Valves.