A dual trip manifold assembly (TMA) includes an isolation valve assembly having a first valve configured to receive a flow of fluid from a hydraulic system fluid supply. The first valve is configured to channel the flow of fluid to at least one hydraulic circuit. The isolation valve assembly also includes a second valve configured to receive the flow of fluid from the at least one hydraulic circuit. The second valve is further configured to channel the fluid flow to a trip header. The first valve and the second valve are synchronized to each other such that rotation of one valve causes a substantially similar rotation in the other valve.

The subject matter of this specification can be embodied in, among other things, a fluid actuator system including a fluid actuator having a housing having an inner wall defining an interior cavity, a piston having a piston head configured for reciprocal movement within the interior cavity, the piston head contacting the inner wall and dividing the interior cavity into a first fluid chamber and a second fluid chamber, a first valve configured to control fluid flow between the first fluid chamber and a bypass conduit, and a second valve configured to control fluid flow between the bypass conduit and the second fluid chamber.

The subject matter of this specification can be embodied in, among other things, a fluid actuator system including a fluid actuator having a housing having an inner wall defining an interior cavity, a piston having a piston head configured for reciprocal movement within the interior cavity, the piston head contacting the inner wall and dividing the interior cavity into a first fluid chamber and a second fluid chamber, a first valve configured to control fluid flow between the first fluid chamber and a bypass conduit, and a second valve configured to control fluid flow between the bypass conduit and the second fluid chamber.

A high-flow valve arrangement in an electro-hydraulic safety control unit to discharge oil volume on instructions from a steam turbine safety system to actuate actuators to stop steam flow in steam turbines to shut-off, is provided. The valve includes a valve body with a flange having a plurality of spaced-apart through holes, a flat-circular plate cartridge and a valve housing configured to each other. The housing includes a chamber to accommodate oil volume; an inlet/outlet port to enable the oil volume to enter and exit therefrom, and a peripheral seat where the cartridge seats. The plate cartridge is capable of being moved upward, defining a very small stroke, upon the increase or decrease of the oil volume in the chamber to open and close the outlets defined via the plurality of spaced-apart through holes to enable and stop the fluid flow therefrom.

The emergency shutoff device is provided with a casing (21) in which inflow ports (22) through which control oil flows into a space (A1) provided therein and a plurality of outflow ports (23) through which the control oil flows outside of the space (A1) are formed; and a switching unit (24) configured to slide along an inner circumferential surface of the casing (21) in which the space (A1) is formed, to change its position relative to the plurality of outflow ports (23), and thus to switch a circulation state of the control oil in the space (A1). The switching unit (24) switches the circulation state between the first circulation state in which the control oil is circulated from a first inflow port (221) to a first outflow port (231) and the third circulation state in which an open and closed state of a test outflow port (236) is switched while the control oil is being circulated from the first inflow port (221) to the first outflow port (231).

A steam turbine valve abnormality monitoring system according to an embodiment includes a detection unit detecting the state of a steam turbine valve or a steam turbine valve drive device, a determination unit, and an abnormality processing unit. Based on the detected result of the detection unit, the determination unit determines whether or not an abnormality has occurred in the opening degree control of the steam turbine valve. The abnormality processing unit issues an alarm or issues a turbine stop command when the determination unit determines that an abnormality has occurred in the opening degree control of the steam turbine valve.

A steam turbine valve abnormality monitoring system according to an embodiment includes a detection unit detecting the state of a steam turbine valve or a steam turbine valve drive device, a determination unit, and an abnormality processing unit. Based on the detected result of the detection unit, the determination unit determines whether or not an abnormality has occurred in the opening degree control of the steam turbine valve. The abnormality processing unit issues an alarm or issues a turbine stop command when the determination unit determines that an abnormality has occurred in the opening degree control of the steam turbine valve.

An emergency shut-off device shuts off supply of control oil to a trip-and-throttle valve of a steam turbine and closes the trip-and-throttle valve in an emergency. The emergency shut-off device includes: a cylinder; a piston that slides into the cylinder; a spring that applies a biasing force to the piston; a plurality of piston valves disposed on the piston; and a plurality of chambers that are formed by the piston valves. The control oil is supplied to and drained from the plurality of chambers, and a sliding surface of each of the piston valves has a groove to leak the control oil in a corresponding one of the chambers to another one of the chambers that is adjacent to the corresponding chamber in an axis direction.

An emergency shut-off device shuts off supply of control oil to a trip-and-throttle valve of a steam turbine and closes the trip-and-throttle valve in an emergency. The emergency shut-off device includes: a cylinder; a piston that slides into the cylinder; a spring that applies a biasing force to the piston; a plurality of piston valves disposed on the piston; and a plurality of chambers that are formed by the piston valves. The control oil is supplied to and drained from the plurality of chambers, and a sliding surface of each of the piston valves has a groove to leak the control oil in a corresponding one of the chambers to another one of the chambers that is adjacent to the corresponding chamber in an axis direction.

A hydraulic lock apparatus includes a hydraulic actuator, a pressure storage device connected to the hydraulic actuator, and a control valve configured to actuate to a first position and a second position. The control valve fluidly isolates the pressure storage device from the hydraulic actuator when the control valve is in the first position. The control valve fluidly connects the pressure storage device to the hydraulic actuator when the control valve is in the second position.