Pneumatics · Directional Control Valves
3/2-Way Valves – Pneumatic Switching & Control
3/2-way valves open, block and exhaust an airflow via three ports and two switching positions – the foundation for reliable pneumatic control in mechanical engineering, automation and plant construction. At STASTO you will find a broad range: from direct-acting solenoid valves and NAMUR versions for direct mounting on rotary actuators to the Serie K and Serie E+V product lines. Briefly describe your switching task – we will recommend the right variant.
Direct-Acting · NAMUR · Series K & E+V
Why STASTO
3/2-Way Valves from a Single Source
Whether a single 3/2-way solenoid valve or a matched valve combination – we support you in selecting the series, actuation type and port size.
Full Range of Functions
3/2-way valves as normally closed (NC) and normally open (NO), monostable or bistable, depending on the series – for control, exhaust and supply applications.
The Right Actuation
Electromagnetic (3/2-way solenoid valve), pneumatic, mechanical or manual actuation. Available actuation types vary by series.
Proven STASTO Series
Series K3.W, E+V and NAMUR combinations for direct mounting on rotary actuators. Exact technical data per item available in the datasheet.
Expert Advice from a Specialist Distributor
B2B contact for maintenance, engineering and purchasing – we assist with series selection, compatibility and accessories.
Product Range
3/2-Way Valves Overview
From direct-acting pilot valve to NAMUR version for actuators – choose the right series.
Variants compared
Direct Acting, NAMUR, Serie K & E+V
The key 3/2-way valve versions at a glance – exact performance data are available in the datasheet for each series.
| Direct-acting | NAMUR | Serie K | Serie E+V | |
|---|---|---|---|---|
| Control principle | Direct | Direct/pilot operated | depending on version | depending on version |
| Typical actuation | Electromagnetic | Electromagnetic | elec./pneum./mech. | elec./pneum./mech. |
| Connector width | depending on series | depending on series | 16 mm | 22 mm |
| Typical application | Pilot/control valve | Valve automation | Standard control tasks | Higher flow rates |
| Direct mounting rotary actuator | no | yes | no | no |
Applications
Where 3/2-way valves are used
3/2-way valves are the standard element for single-acting control tasks in pneumatics.
Single-acting cylinders
Extension via pressure actuation, return via spring force after exhaust – the classic 3/2 control task in mechanical engineering.
Pressurising and exhausting
Safe shut-off and pressure relief of pneumatic consumers within the compressed air supply.
Pilot and pilot control
As a pilot valve for actuating larger directional control or process valves in process engineering systems.
Valve automation (NAMUR)
Direct mounting on rotary actuators for opening and closing process valves – no additional tubing required.
Pneumatic actuation
Switching pneumatic functions in special vehicles and superstructures – compact valves for rugged environments.
Switching vacuum
Switching vacuum in pneumatic systems – depending on series and version.
Buyer's Guide
Selecting the Right 3/2-Way Valve
The most important selection criteria at a glance – from designation to port size.
Fundamentals & Function
- What does "3/2" mean?
- The first number indicates the number of ports (3), the second the switching positions (2): pressure (P), work port (A) and exhaust (R/E), plus two switching states.
- Normally Closed (NC) or Normally Open (NO)?
- In the rest position, a normally closed (NC) valve is blocked and only opens when actuated; a normally open (NO) valve is open in its default state. The choice depends on the safe state required by your application.
- Basic Function
- A 3/2-way valve pressurises an actuator and blocks or exhausts it in the second position – the basis of many pneumatic control systems.
Selection & Technology
- Actuation Type
- Electromagnetic (3/2-way solenoid valve) for signal control, pneumatic for pilot pressure, mechanical/manual for local operation. Availability varies by series.
- Direct-Acting or Pilot-Operated?
- Direct-acting valves switch independently of operating pressure and respond quickly; pilot-operated versions use the available pressure and allow higher flow rates.
- Port Size & Flow Rate
- Select the nominal bore and port connection (e.g. thread) to match the required flow rate. Exact performance data can be found in the series datasheet.
Availability & service
Delivery, accessories and enquiry
We supply not just valves, but the complete package for your control application.
Availability
Many 3/2-way valves are available at short notice depending on series and variant; please contact us for specific availability and lead times for the selected item.
Variants & accessories
Matching solenoid coils, connectors, port kits (e.g. NAMUR) and valve manifolds – depending on series and version.
Enquiry & quotation
For project quantities, special versions or coordinated combinations, we will be happy to prepare a tailored quotation.
Frequently Asked Questions
FAQ on 3/2-way valves
Answers to the most important questions about function, actuation and selection.
What is a 3/2-way valve?
A 3/2-way valve has three ports and two switching positions. It can pressurise an actuator and in the second position block and exhaust it – the basic function of many pneumatic control systems.
What is a 3/2-way valve used for in pneumatics?
Primarily for controlling single-acting cylinders, for pressurising and exhausting actuators, as a pilot/control valve and for switching vacuum.
What is the difference between a 3/2 and a 5/2-way valve?
The 3/2 valve typically controls single-acting actuators; the 5/2-way valve has five ports and is used for double-acting cylinders. Suitable 5/2 versions are also available from STASTO.
What do NC (normally closed) and NO (normally open) mean?
NC (normally closed) is blocked in the rest position, NO (normally open) is open in the rest position. The choice depends on the required safe default state.
What is a 3/2-way solenoid valve?
A 3/2-way valve with solenoid actuation: an electrical signal energises the solenoid coil and switches the valve. It is the most common actuation type for automated control systems.
What does the NAMUR version mean?
NAMUR refers to a standardised mounting interface that allows the valve to be mounted directly onto pneumatic rotary/quarter-turn actuators – without additional pipework.
Which series is the right one for me?
This depends on flow rate, actuation type and installation situation. Serie K (16 mm) and Serie E+V (22 mm) cover many standard applications; NAMUR versions are ideal for actuators. We are happy to advise you on the right variant.
Related categories
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Complementary directional control valves and series for your pneumatic control system.
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