The lifetime of solenoid valves depends on many factors. The decisive factors here are the differential pressure, the number of cycles, the type and density of the medium used and finally the seals used. Due to the higher moving masses and the associated forces, large solenoid systems have a shorter service life than smaller and therefore lighter solenoid systems. In order to precisely determine the lifetime for the special customer application, an endurance test under realistic conditions is most of the times unavoidable..
Ways to increase service life:
Use of guide rings:
When using guide rings, the magnetic core is guided precisely, so there is no metallic contact friction between the magnetic core and the guide tube. In addition, the core speed is slightly slowed down during the shifting process. This optimization step can significantly increase the lifetime of the valve.
Spring-loaded damping:
The use of damping by a spring-loaded pin protruding about 0.1mm (see figure) or a spring-loaded elastomeric bumper cushions the impact of the plunger on the pole.
Damping discs:
The use of damping discs between the plunger and the pole can increase the lifetime of the solenoid system and also reduce the noise during the switching process, since metal parts no longer collide. This type of damping can only be used with direct current systems, because with alternating current the plunger and the pole must lie directly next to each other without any gap in order to prevent increased power consumption (inadmissible heating) and “hum”. With suitable damping discs, we have already been able to successfully test switching numbers of >100 million switching cycles.
