Valve technology

Vacuum valves are used to control the vacuum and to improve the process safety in vacuum-gripper systems.

A distinction is made between three groups of valves, according to their principle of operation:

• Solenoid valves for vacuum and compressed-air


• Manually actuated vacuum and compressed-air valves


• Check valves and flow resistors

Solenoid valves

Solenoid valves are used to control the flow of vacuum and compressed- air. The valves themselves are controlled with the aid of electrical signals. Solenoid valves are available in various nominal sizes, permitting selection of a valve which precisely matches the customer-specific requirements. Solenoid valves are available in directly controlled versions (EMV, EMVO) and versions with pneumatic pilot control. The latter are particularly quick-acting valves.

Check valves, flow resistros and sensing valves

Check valves, flow resistors and sensing valves are used to improve process safety in a vacuum system.

Check valves close automatically when the volume-flow of air through them exceeds a preset value. They can thus be used to deactivate suction pads in a gripper system which are not in contact with the workpiece and to maintain the vacuum in the rest of the system.

Flow resistors reduce the cross-sectional area of the vacuum system and are used primarily in systems used for the handling of porous materials. The reduced cross-sectional area ensures that the system vacuum is maintained even if one or more suction pads are not in contact with the workpiece.

Sensing valves have a spring-loaded plunger which detects whether the suction pad is in contact with the workpiece. If this is the case, the valve opens and applies vacuum to the suction pad.

Important:
Sensing valves provide no protection against vacuum loss caused by suction pads which are only partially in contact with the workpiece!

Manually actuated vacuum and compressed-air valves

Valves of this type are used in particular for the manual activation and deactivation of vacuum or compressed-air circuits or of individual suction pads in lifting devices. They are available as 2/2-way or 3/2-way valves.

The following table should help you to select the appropriate components:

Helpful downloads

Further information:

© Schmalz 2012