# 5/2-Way Pneumatic Valve

> Source: https://rodlesspneumatic.com/resource-center/pneumatic-glossary/5-2-way-pneumatic-valve/
> Language: en-US
> Category: Valves & circuits

## Definition

A 5/2 pneumatic valve has five ports and two switching positions. One supply port is alternately connected to either of two working ports, while the opposite working port is connected to one of two exhaust ports. This arrangement is commonly used to extend and retract a double-acting cylinder.

## Key facts

- **Port count:** 5: supply, two working, two exhaust
- **Position count:** 2 switching states
- **Typical load:** Double-acting cylinder

## 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.

## What to verify before selection

- Circuit symbol and normal state
- Spring return or bistable actuation
- Required flow and pressure range
- Pilot supply and minimum pilot pressure
- Coil voltage and connector
- Port thread and manifold interface

## 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

## Frequently asked questions

### Can 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.

### What 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.

## Technical references

- [ISO 1219-1:2012 — Fluid power graphical symbols](https://www.iso.org/standard/60184.html): Rules and basic elements for fluid power symbols used on components and circuit diagrams.
- [ISO 4414:2010 — Pneumatic system safety](https://www.iso.org/standard/44790.html): General rules and safety requirements for pneumatic systems and their components.