AUTHOR : admin FROM : 未知 ADD TIME : 2020-12-28 11:37  HITS : BELONG : INDUSTRY NEWS
  • Actuator and Local Panel Schematic Diagram of Shutdown Valve

    In typical the shutdown valve (ball valve) is actuated by a piston type actuator with solenoid valve as a trigger

    by supervise the instrument air supply to the actuator. In simplify manner, the shutdown valve actuator and local

    panel can be constructed from a pressure regulator valve (usually comes complete with pressure gauge and filter)

    and solenoid valve. Further modification may be needed depends on the ball valve or shutdown valve actuated

    triggering and also the requirement of closing speed, opening speed etc. The modification can be an additional

    quick exhaust, flow control, solenoid valve with manual reset, manual key operated valve for partial stroke test etc.

    But all of them is derived from the basic actuator and local panel schematic diagram (see picture below).

    At no electric power applied to the solenoid valve, the solenoid valve is on its failure position (normally close).

    The instrument air supply to the actuator is blocked. The ball valve is on its failure position (failure close).

    When the solenoid valve is energized, the instrument air supply can go to the actuator and causing a valve

    actuated (in open position). Once again if the electric power to the solenoid valve is off, the instrument air

    supply will be blocked and the actuator spring will try to force the actuator back to its failure position (failure close).

    This movement will make the instrument air inside the piston vented through the exhaust port of