// Catalogue

4/2 Way Valves for Driving Double-Acting Cylinders

4/2 way valves have four ports and two positions. They send pressure to one side of a double-acting cylinder or motor while the other side returns to tank. TSA Hydraulics Engineering supplies them within the Directional Control family of our Valves range, mainly for hydraulic circuits.

The question that matters most: what should the cylinder do when the power drops? A single solenoid valve springs home, while a double solenoid valve stays where it was last sent. Swap one for the other and the machine behaves differently. Send the model code, and we will match a genuine valve or an equivalent with the same behaviour.

// Buying guide

How a 4/2 Way Valve Works

The four ports are pressure (P), tank (T) and two work ports (A and B).

Position one: P connects to A, and B returns to T. The cylinder extends.
Position two: P connects to B, and A returns to T. The cylinder retracts.

There is no middle position, so the actuator is always being driven one way or the other.

Single Solenoid or Double Solenoid?

Single solenoid, spring return: one coil shifts the spool, and a spring pushes it back when the coil switches off. The valve always returns to a known position on power loss.
Double solenoid with detent: one coil for each direction. A small detent holds the spool where it was last shifted, so the valve remembers its position even with no power.
Double solenoid, spring centred: rare on 2 position valves, but some designs exist. Check the symbol carefully.

Pick the one that gives a safe result if the power fails mid cycle.

4/2 or a 3 Position Valve?

A 4/2 valve cannot stop a cylinder part way or let the pump unload at rest. To hold a load in the middle of its stroke, or let the pump idle between cycles, you need a 3 position valve with the right centre. In pneumatics, the 5/3 way valve does this job, and in hydraulics the 4/3 valve does the same.

4/2 in Air Circuits

Pneumatic 4/2 valves exist, but most air circuits use 5/2 valves instead. The extra exhaust port lets you fit a separate speed control on each stroke, which is hard to do with a single shared exhaust.

Mounting and Sizes

Most hydraulic 4/2 valves mount on a subplate or manifold to ISO 4401, and NG6 (CETOP 3) and NG10 (CETOP 5) are the most common sizes. Many sit on the manifold of a hydraulic power unit. Cartridge versions screw into a cavity in a custom block. Check the size and any extra pilot or drain ports before you order.

Switching Tips

DC coils switch more softly than AC coils, which reduces shock in the pipework.
If the valve stops shifting, use the manual override to test the spool.
Keep the oil clean. Fine dirt is the most common cause of a sticking spool.

Where 4/2 Way Valves Work

Clamping and work holding cylinders
Presses and forming machines with simple extend and retract cycles
Hydraulic motors driving conveyors, mixers and winches in either direction
Gates, doors and lifting tables
Machine tools and automation cells

4/2 Way Valves Specifications to Check

Spool symbol and position behaviour: spring return or detent
Size and mounting: CETOP 3, CETOP 5, cartridge or ported body
Coil voltage, AC or DC, and the connector
Maximum pressure and flow
Pilot and drain arrangement on larger valves

Why Buy From TSA Hydraulics Engineering

As a 4/2 way valves supplier, we match the spool behaviour, coil and mounting so the machine runs exactly as before. You get clear prices in AUD, OEM or equivalent options, and help sourcing 4/2 way valves replacement parts such as coils, connectors and seal kits. We tell you upfront whether a valve is genuine or an equivalent.

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