THREE-POSITION PNEUMATIC ACTUATOR

The three-position actuator is mainly used for the process control of 3-way or 4-way valves or other three-position rotating devices.We provide 2 kinds of three-position actuators: 90° range (mid-position from 20° to 80°) and

180° range (mid-position from 90° to 170°)
 

The mid-position of three-position actuator is achieved by a set of mechanical stops from 2 auxiliary pistons and adjusting limit screws.

Position 1 (middle position)

Air source pressure enters port 2 and port D at the same time, air is discharged from port 4 and port C, port 2 moves as an internal piston, and port D is limited by the auxiliary piston push rod to limit the internal piston to be positioned at a predetermined intermediate position.

Position 2 (full open position)

The air source pressure enters port 2 and port C at the same time, the air is discharged from port 4 and port D, and the internal piston of port 2 continues to move.causing the pinion to rotate to the full open position.

Position 3 (full closed position)

Air source pressure enters port 4, air is discharged from port 2, and the internal piston moves to the middle direction to reach the full closed position.