The HC-2 Type Controlair Valves are handle operated 4-way, exhausted center, pressure control valves.
The typical unit contains two directional control 3-way side valves and a pressure graduating portion that is arranged to increase, decrease or maintain air pressure to (2) separate delivery lines. In neutral position both 3-way side valves exhaust both delivery lines. A movement of 10 degrees either side of center position opens
the appropriate side valve and directs pressure to the indicated outlet port. Continued move-ment past 10 degrees up to full travel or 46 degrees either side of neutral continues to ac-tuate the pressure-graduating portion to deliver a graduated pressure according to the value of the control spring.
There are four models with similar valve func-tions, but different handle operating character-istics.
HC-2-X Controlair Valve -Handle is spring returned to neutral position from all positions in the handle travel. Some special models exist.
HC-2-LX Controlair Valve – Handle is spring returned to neutral position from all positions except at the maximum pressure setting on both sides of center. The handle is held in both extreme positions by a mechanical detent.
HC-2-FX Controlair Valve – Handle is equipped with a friction brake that will hold the handle in any position selected in the handle travel.
HC-2-SX Controlair Valve – Handle holds in only one maximum pressure position. The han-dle is spring returned to neutral position from all other positions in the handle travel. The valve can be ordered to hold in either extreme position.