A retarder control valve assembly and system for controlling speed of rail cars, utilizes cartridge valves carried in a manifold body including piping and pilot control apparatus, but no wearing surfaces, dynamic seals, or moving parts. The cartridge valves are replaceable without replumbing, and include all moving valve elements and dynamic seals. The valves each include a piston controlled poppet carried on a spool movable within a cartridge body to open and close the valve and supported to withstand high side loads. The pressure sensing and feedback to the retarder system controller is at the manifold, in a pressure spike attenuating circuit having a phase modulating capability to mimic retarder pressure remotely.

A pressure relief valve includes a valve body, a valve seat, a bonnet, and a valve actuator. The valve body has an open top, a bottom, a back and a front with a cavity formed within. A cap with a first vent is removably attached to the open top. An inlet opening and a discharge opening are in fluid communication with the cavity is formed at the bottom and front of the valve body respectively. The valve seat is circumferentially disposed around the inlet opening within the cavity. A recessed area is formed on a surface on the distal end of the valve seat that is configured to receive a lip seal. The bonnet has a closed top end with a second vent. The valve actuator is coupled within the bonnet to a set-pressure enabling means that is not a mechanical spring.

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.

A speed controller capable of controlling an action speed of an external cylinder in one stroke in a step-wise manner. The speed controller includes a first flow path and a second flow path that allow a first port and a second port to be in communication with each other. The first flow path is provided with a first check valve for allowing flow from the first port to the second port. The second flow path is provided with a first needle valve, and an opening hole of the first check valve is constituted as a part of a flow path. The first needle valve adjusts the flow rate by changing an opening area of the opening hole with a tip portion fixed on a piston in the cylinder chamber. The speed controller further includes a third flow path allowing the first port and the cylinder chamber to be in communication with each other. The third flow path is provided with a second check valve for allowing flow from the first port to the cylinder chamber.

The annular space surrounding a flow tube in a subsurface safety valve is sealingly isolated at opposed ends of the flow tube and pressure compensated to the tubing pressure. The subsurface safety valve is inserted and aligned in an outer housing so that hydraulic operating connections are sealingly aligned with opposite hand split ring seals that are properly compressed when the safety valve is secured in its surrounding housing. The assembly is then able to meet high pressure, heavy debris, and marine environment service requirements for subsea conditions with minimal reconfiguration for what would otherwise serve as a borehole subsurface safety valve.

A three-position booster valve mechanism includes an operating member for moving a supply and exhaust valve. A piston-cylinder control system is provided for moving the operating member between a first position in which the supply and exhaust valve are closed, a second position in which the supply valve is open and the exhaust valve is closed, and a third position in which the supply valve is closed and the exhaust valve is open. A pilot port is provided for moving the operating member in between the first, second and third positions in dependence of a pilot pressure. The piston-cylinder control system connects to the operating member at a central point of application in between the supply and exhaust valve. The operating member extends in opposing directions from the central point of application towards the supply and exhaust valve.

A valve (10) comprising a bore (14) extending about an actuation axis (A), wherein a spool (34) inside the bore (14) is actuated between a first working position and a second working position, and a first circumferential seal wing (56A) and a second circumferential seal wing (56B) being arranged on the spool (34). In the first working position, the first seal wing (56A) abuts to an outer first recess wall (24a) and the second seal wing (56B) abuts to an inner second recess wall (24c), so as to open some flow paths and close other flow paths. In the second working position, the first seal wing (56A) abuts to an inner first recess wall (24b) and the second seal wing (56B) abuts to an outer second recess wall (24d), so as to close some flow paths and open other flow paths.

A flow control device includes a housing with an inlet and an outlet and a flow conduit disposed in the housing. The inlet, the flow conduit, and the outlet define a flow passage. A valve seat is disposed in the housing downstream of the inlet, and a shuttle is movably disposed in the housing and displaceable between a closed position engaging the valve seat to close the flow passage and an open position spaced from the valve seat to open the flow passage. A sealed chamber is defined between the housing and the flow conduit. A port coupled with a source of pressurized fluid communicates with the sealed chamber, where the shuttle is displaceable between the closed position and the open position based on a pressure in the sealed chamber. The threshold water pressure for displacing the flow conduit may be adjustable by modifying the pressure in the sealed chamber.

Example devices include a fluidic device, such as a fluidic valve, including a body formed from a rigid body material including a fluidic source, a fluidic drain, and a fluidic gate, each of which may have a fluid connection with a chamber, or a portion thereof. The device may further include a gate transmission element, located within the chamber, that is controllable between at least a first position and a second position using a gate pressure received through the fluidic drain. Adjustment of the position of the gate transmission element may allow control of fluid flow through the device. Other devices, methods, systems, and computer-readable media are also disclosed.

A check valve (1) which comprises an obturator (2) and a biasing mechanism, the biasing mechanism arranged to urge the obturator towards a closed condition, and the check valve further comprising an actuator assembly (5, 7a, 7b) which is arranged to be selectively activated to cause the obturator to be in an open condition, and the check valve comprising a controller which has a control signal input to cause the controller to selectively activate the actuator assembly.