Directly controlled vacuum valves
When using a solenoid to control the valve, the valve flap is operated directly and a pneumatic line is not necessary. Versions with the switching functions NO (normally open) and NC (normally closed) are available separately.
Valves supported by compressed air
These valves are used in applications that require short cycle times and correspondingly fast switching operations. The valve function is supported by controlled compressed air.
The switching functions, NO and NC, can be realized with the same valve, since the vacuum supply and blow-off / bleeding or vent connections can be interchanged. It is not necessary to have a pneumatic line for these vacuum valves.