| 摘要 |
<p>The invention relates to a device for dynamically monitoring pressure differences in at least two pressure pipes (207, 211), preferably in safety valves of pneumatically operated consumers. The inventive device is characterized in that, if the pressure in the two pressure pipes is equal, the restoring force of the at least one readjusting spring (205) together with the pressure force acting upon the pressure surface (A2) facing the at least one readjusting spring is larger than the pressure force (a1) acting upon the pressure surface facing away from the readjusting spring, thereby maintaining the piston-cylinder unit (202) in its rest position. The piston-cylinder unit changes to a storage position even if the pressure force acting upon the pressure surface facing the at least one readjusting spring (205) is reduced only for a short time. In said storage position, the pressure force acting upon the pressure surface facing away from the readjusting spring (205) is larger than the sum of the elastic force and the pressure force acting upon a third entrance surface (A3) when again impinged upon with a pressurized fluid. The piston-cylinder unit can only be restored from the storage position to the rest position by removing the pressure acting upon the pressure surface facing away from the readjusting spring.</p> |
