A temperature control fluid is introduced through a first port. The temperature control fluid introduced into the first port is discharged through a second port. A piston is configured to be moved by a pressure to open or close a path connecting the first port and the second port. A pressure control space is provided at at least one side of a moving direction of the piston when the path is opened or closed. Air is supplied into the pressure control space through a third port. A leak portion communicates with the pressure control space, and allows the air supplied into the pressure control space to leak therethrough.

A temperature control fluid is introduced through a first port. The temperature control fluid introduced into the first port is discharged through a second port. A piston is configured to be moved by a pressure to open or close a path connecting the first port and the second port. A pressure control space is provided at at least one side of a moving direction of the piston when the path is opened or closed. Air is supplied into the pressure control space through a third port. A leak portion communicates with the pressure control space, and allows the air supplied into the pressure control space to leak therethrough.

An actuator includes a housing defining an inlet port, a piston and a return spring disposed within the housing, and an elastically deformable element. The return spring is configured to apply a biasing force to the piston to move the piston to a spring return position. A first fluid pressure applied to the inlet port moves the piston against the biasing force of the return spring to a first actuated position in which the piston indirectly engages a stop portion of the actuator housing. A second fluid pressure, greater than the first fluid pressure, applied to the inlet port moves the piston against the elastically deformable element to compress the elastically deformable element to move the piston to a second actuated position beyond the first actuated position.

A subplate mounted (SPM) valve includes a valve body having pilot port, a piston configured to be actuated by fluid from the pilot port, a first control chamber and second control chamber each formed in the valve body and fluidicly isolated from the pilot port, a first flow restrictor fluidicly disposed between the first control chamber and the second control chamber and configured to restrict flow in at least one direction between the first control chamber and the second control chamber, a cage coupled to the valve body and having a supply port, a return port, and a work port, and a spool slidably engaged with the cage and configured to selectively restrict flow between the supply port and the return port by actuation of the piston.

A fluid control device, capable of detecting leaks even if the leaks is slight, is provided. The fluid control device includes a valve body in which the flow path is formed, a diaphragm isolating a closed space from the flow path, a bonnet forming the closed space between the diaphragm and providing a penetration hole connected to the closed space and penetrated to be able to vertically move a diaphragm retainer, the diaphragm retainer vertically moving in the penetration hole to press the diaphragm and providing an increased diameter portion not to be removed from the penetration hole, a pressure sensor detecting a pressure inside of the closed space, and an elastic body interposing between the increased diameter portion of the diaphragm retainer and the bonnet inside of the closed space and elastically expanding and deflating between the increased diameter portion of the diaphragm retainer and the bonnet as the diaphragm retainer vertically moves.

A technique facilitates actuation of a downhole device, e.g. a flow control valve. The downhole device is shifted between positions by an actuator piston, which is movable in a first direction via hydraulic actuating fluid supplied by a first control line and in a second direction via hydraulic actuating fluid supplied by a second control line. A hydraulic circuit is coupled between the first control line and the second control line to enable a complete stroke of the actuator piston in one direction, e.g. the second direction, while limiting movement of the actuator piston to incremental movements in the other direction, e.g. the first direction. The hydraulic circuit employs a hydraulic enabled regulator having a plurality of pistons arranged to control the supply of hydraulic actuating fluid to achieve the desired incremental movements of the actuator piston.

An apparatus for applying viscous material to workpieces has at least two material outlets. A needle valve is assigned to each material outlet, the valve needle of which being able to close the respective material outlet on a valve seat. Each valve needle is assigned a cylinder, in the piston chamber of which a piston is movable by pressure applied by a fluid, and which cylinder has a piston rod for impingement on the respective valve needle, the piston rod being connected to the piston, being guided out of the piston chamber on an end face facing the valve seats and extending longitudinally. The cylinders are arranged one behind the other longitudinally and the piston rod of at least one of the cylinders is guided in a sealed manner through the piston chamber of at least one further cylinder arranged closer on the valve seats.

An apparatus for applying viscous material to workpieces has at least two material outlets. A needle valve is assigned to each material outlet, the valve needle of which being able to close the respective material outlet on a valve seat. Each valve needle is assigned a cylinder, in the piston chamber of which a piston is movable by pressure applied by a fluid, and which cylinder has a piston rod for impingement on the respective valve needle, the piston rod being connected to the piston, being guided out of the piston chamber on an end face facing the valve seats and extending longitudinally. The cylinders are arranged one behind the other longitudinally and the piston rod of at least one of the cylinders is guided in a sealed manner through the piston chamber of at least one further cylinder arranged closer on the valve seats.

Provided is an actuator including a ball-type thrust amplifier therein that controls a valve in which a high-pressure fluid flows, and having less wear between members and a long lifespan. This actuator for a valve includes a thrust amplification mechanism therein, in which the thrust amplification mechanism includes a disk, a ball presser, a stem, and a plurality of balls that are sandwiched by and in contact with an upper surface of the disk, a tapered surface of the ball presser, and a tapered surface of the stem and disposed to move outward as the stem moves downward, the surfaces of the parts constituting the thrust amplification mechanism are coated with grease containing an additive, and the additive of the grease includes at least chloroalkane.