Type WSV soft-start valves are used for controlled, slow pressure build-up within a pneumatically controlled system. They can be used either in front of a valve group, a single valve or between a valve and cylinder.

The system pressure pe at port 1 is fed to outlet 2 via the charging throttle. The adjustable charging throttle controls the pressure increase over time. When approx. 60% of the system pressure pe is reached, the valve switches through abruptly and the full nominal size of the valve is opened.

If the mains pressure is switched off, the soft-start valve vents from port 2 to port 1.

Due to their properties, soft-start valves are primarily used to protect devices. The continuous, slow, adjustable pressure increase protects the connected devices and therefore enables a significantly longer service life for actuators such as air cylinders, but also for valves. A hard stop (e.g. compressed air cylinder) is prevented but the full force of the actuator is still called up with a defined time delay.

Soft-start valves are also used to move systems slowly and gently into the starting position.

Due to their special properties, soft-start valves are often installed in conjunction with maintenance units.

We at SFS build this special “pneumatic soft-start valve” in sizes G1/4 and G1/2.

We would be happy to advise you on the correct design for your pneumatic application.