Sicherheitsventil

摘要

An emergency isolation valve has a valve plug in a valve body (1) connected to a pipeline (3). The valve plug is connected to a valve shaft (4) around which a sector gear (16) is provided and engaged with a rack (14) of a piston rod (10) in a cylinder (2). The piston rod has a piston (11) at one end and is connected to a compression spring (13) at the other end. The piston (11) is moved by air supplied into a cylinder from a compressed air source via a fluid control and a solenoid selector valve. Air supply stops and a discharge hole (21) of the cylinder is opened, so that air is discharged to the outside. The piston (11) is returned by the compression spring (13) to close the discharge hole (21). At the same time stop of the piston rod (10) is detected by a sensor (25) thereby checking whether to actuate the valve plug normally even during operation.