S9A-series Parker - Refrigerating Specialties Gas Powered Suction Stop Valve- Pilot Assemblies

This heavy duty gas powered valve is suitable for Ammonia, R-12, R-22, and R-502, 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 is a pilot operated valve 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) above valve internal upstream pressure for positive opening. This valve is normally closed.
The S9A valve is designed to promptly and fully open or close under conditions which make conventional solenoid valves unreliable or unsuitable, such as viscous oil conditions, location in a vertical pipeline, or where very low valve pressure drop is required.
The S9A valve is a two-position valve 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.
The S9A is not a check valve and will permit reverse flow if the downstream pressure is higher than the upstream pressure. Features:

• Low Pressure Drop for Low Temperature Operation
• Suitable to -50°C (-60°F)
• Can Be Installed in Vertical or Horizontal Position
• Manual Opening Feature
• 27.6 bar (400 PSIG) Maximum Rated Pressure (MRP)