5/2-Way Pneumatic Valve | Glossary

Read the circuit symbol before the port labels

The two adjacent boxes show the two switching states. Flow arrows and blocked-port marks inside each box show the connections in that state. Port numbering often follows a common convention, but the product diagram and marking remain authoritative for the actual valve.

Monostable and bistable behavior

A spring-return 5/2 valve returns to its defined normal state when the actuation signal is removed. A double-solenoid or double-pilot valve can remain in its last commanded state until the opposite signal arrives. That memory behavior changes the machine response after signal or power loss.

A 5/2 label is not a complete replacement specification

Two valves can share the same port/position count but differ in flow capacity, pressure range, pilot requirement, voltage, connector, response time, spool overlap, manual override, manifold interface, thread, seal material, and environmental protection.

Selection checklist

What to verify before selection

01
Circuit symbol and normal state
02
Spring return or bistable actuation
03
Required flow and pressure range
04
Pilot supply and minimum pilot pressure
05
Coil voltage and connector
06
Port thread and manifold interface

Application caution

Common mistakes

Assuming every manufacturer uses the same visible port arrangement
Replacing a bistable valve with spring return
Selecting from 5/2 and port size without checking flow or pilot pressure

FAQ

Questions engineers often ask

01Terminology checkCan a 5/2 valve control a single-acting cylinder?

It can be adapted in some circuits, but a 3/2 valve is normally the simpler functional choice for a single-acting actuator.

02Terminology checkWhat happens when a 5/2 solenoid valve loses power?

It depends on the actuation design. A spring-return valve returns to its normal state; a bistable valve may remain in its last state.