ASCO 4-WAY Valve Operation

Four-ported valves are generally used to operate double-acting cylinders or actuators.

They have four or five pipe connections, commonly called ports:

  • One pressure inlet
  • Two cylinder ports providing pressure to the double-acting cylinder or actuator.
  • One or two outlets to exhaust pressure from the cylinders.

In a de-energized position, pressure is connected to one cylinder port; the other port is connected to the exhaust. In an energized position, pressure and exhaust are reversed. Four ports means less piping is required. With five ports, independent speed controls can be mounted in each port.

Three Types of Constructions Apply

Single Solenoid – When the solenoid is energized, the valve shifts, then returns to the original position when de-energized.

Dual Solenoid – When one solenoid is energized, the valve shifts, then returns when the other solenoid is energized. They may be energized momentarily or continuously, but never concurrently. Some valves, both single and dual solenoid, may change position on loss of fluid pressure.

Single Air Operator – When the operator is pressurized, the valve shifts, then returns when the pressure is removed.

ASCO Engineering Guide (PDF)