Solenoid valves: interfaces between the electric control level and the pneumatic actuator

Solenoid valves by SAMSON
|   Know how

Solenoid valves serve as switching elements for the opening and closing of the valve assembly or act as safety control circuits for connected valve accessories to form the interface between the electric control level and the pneumatic actuator.

SAMSON solenoid valves are characterized by their high level of operational reliability and minimal power consumption. The Type 3969  Solenoid  Valve  also  operates  without  consuming  air  and is a particularly energy-efficient solution.

SAMSON  solenoid  valves  are  available  with either Whitworth pipe threads (G) or threads according to national pipe thread standards (NPT).

3/2, 5/2, 5/3 or 6/2-way functions can be implemented depending on the solenoid valve version used.

Switching functionType

Numerous types of attachment are available for SAMSON solenoid valves. In addition to direct attachment to linear actuators according to IEC 60534-6 (NAMUR) and rotary actuators according to VDI/VDE 3845 or 3847, the solenoid valves can be mounted on rails or walls.

Direct attachment to actuator 
Hooked up as required 
VDI/VDE 3845

The solenoid valves meet high quality requirements and are suitable for use in safety-instrumented systems up to SIL 3 (redundant configuration) observing the requirements of IEC 61511 and the required hardware fault tolerance.

In safety-instrumented systems, solenoid valves are often used in redundant setups. In this way, if one solenoid valve fails, the fail-safe action of the actuator is still guaranteed by a second solenoid valve. SAMSON has designed a redundancy plate for this version to allow two solenoid valves to be connected in series or in parallel without any additional hook-up. The solenoid valves are mounted on the left and right side to the NAMUR interfaces of the redundancy plate.

Safety function SIL

The switching function in the solenoid valves is performed by an electropneumatic binary converter, which has proven reliable in service a million times over. Thanks to its low power consumption, the type of protection intrinsic safety (Ex i) is possible.

Other possible types of protection include flameproof enclosure (Ex d) and non-sparking equipment (Ex n).

Type of protectionType
Intrinsic safety Ex i
Flameproof enclosure Ex d
Non-sparking equipment Ex n  


Emergency venting

The hook-up consists of a pneumatic actuator with positioner, limit switch and solenoid valve for emergency venting of the actuator. The signal issued by the limit switch when the valve travel exceeds or falls below an adjusted limit can be used to activate the solenoid valve.

1 Solenoid valve – 2 Supply pressure regulator – 3 Control valve – 4 Positioner – 5 Limit switch

On/off service

On/off applications can be implemented by a solenoid valve as the single mounted device on the valve assembly. An additional external power supply is not required for this hook-up since the air supply is fed internally to the solenoid valve.

1 Solenoid valve - 2 Supply pressure regulator - 3 Control valve

In combination with a positioner

In combination with a positioner, the solenoid valve provides additional emergency shutdown to extend the control function of the valve assembly. In this case, the solenoid valve is connected directly upstream of the actuator.

In the event of emergency, the solenoid valve ensures that the actuator is vented and moves to the  fail-safe position. In throttling service, an external pilot supply of the solenoid valve is always necessary.

1 Solenoid valve – 2 Supply pressure regulator – 3 Control valve – 4 Positioner

Together with valve accessories, pneumatic control valves serve as engineered solutions for special applications. SAMSON has been developing and manufacturing high-quality valves, actuators and valve accessories for over 100 years. Thanks to our experience and expertise as well as customer requirements, we have continuously developed the individual components and optimized their interaction.

Click here for information on other valve accessories and hook-ups: