Valve shutter control system comprises sealed variable-volume chamber containing incompressible fluid and freely-moving rod

摘要

The control system consists of a sealed chamber (1) of variable volume, filled with an incompressible fluid (5) of any chemical or physical nature and having a sealed aperture for a moving rod (6). The rod is moved axially or rotated by a control unit (8) to vary the volume of the chamber, while the latter is in contact with the valve shutter (3) via a piston (2), so that an increase in the chamber's volume presses the shutter against the valve seat (4). When the pressure is released the valve is opened by a return spring (10).