| 摘要 |
The invention relates to a High Integrity Pressure Protecting Systems (HIPPS 1), wherein the HIPPS has an ON/OFF valve (2), with a housing (10), wherein the housing has an inlet (11) and an outlet (12), and a conduit (13) for passage of a fluid from the inlet to the outlet, and with a closure member (14), and a hydraulic actuator (3), having a control element (23) that is kinematically fixed to the closure member, and a switchable hydraulic supply unit (4), which in an active state supplies a control face (25) of the control element (23) with a control pressure, and in a passive state releases the control pressure from the control face (25), a sensor measuring a pressure of the fluid, downstream of the outlet (12), and a logic solver that compares the pressure to a critical value, that switches the hydraulic supply unit to the active state for allowing the closure member to stay in the open position, whenever the pressure is below the critical value, and that switches the hydraulic supply unit to the passive state for allowing the closure member to move into, or to stay in the closing position, whenever the pressure exceeds the critical value. The invention suggests that an opposite face of the control element, opposite to the control face is exposed to the downstream pressure of the fluid, so that the downstream pressure of the fluid pushes the closure member into the closing position. |
