Air/Hoist Control Valves - 290 Series
  The Kingston 290 Series "two step" air control valves are designed for operating single acting cylinders as found on various lifting devices. When compressed air is directed through the inlet side, or "first step" of the valve to the cylinder port, the cylinder is extended. As long as the lever remains in the neutral position, the air pressure in the cylinder holds the piston extended. When the exhaust port, or "second step" is opened, the air pressure is exhausted to atmosphere, allowing the load on the cylinder to return the piston to its "rest" position.

Valves are of brass construction with Buna-N seals. Inlet stem is designed to provide restricted flow on initial opening, with full flow when fully open. Maximum operating pressure, 150 PSI.

CAUTION: If during normal operation the inlet port is disconnected from its air pressure source, under certain conditions reverse flow can occur, resulting in system pressure loss. Reduced system pressure will allow the load to be lowered proportionally, possibly causing injury. In this type of use, a check valve attached to the inlet to prevent reverse flow is mandatory for safety.