Provided is a check valve device having a structure with which pressurized fluid is less likely to leak from a flowpath blocked by a valve. A flowpath is formed in a block, and a main valve and a sub-valve are provided in series along the flowpath. A primary-side chamber, an intermediate chamber, and a secondary-side chamber, which form a section of the flowpath, are formed in that order from the one end of the flowpath to the other end thereof. The main valve and the sub-valve are opened by a pilot valve.

A valve assembly structured to reduce the volume of water along a path of fluid flow of a water supply line, including a valve body having a stabilizing chamber, a receiving chamber, and a valve member disposed therein. The valve member is disposable between an open orientation and a closed orientation relative to fluid flow between the stabilizing and receiving chambers. A biasing structure is disposed to normally bias said valve member into the closed orientation and is configured to exert a predetermined biasing force on said valve member. A transfer passage is disposed in fluid communication with and between the stabilizing and receiving chambers and is configured to define and direct a decreased volume of fluid flow, at an increased water pressure, on said valve member, wherein the increased water pressure is greater than the predetermined biasing force and sufficient to dispose the valve member in the open orientation.

A device for holding a hydraulic cylinder stem in position includes a hydraulic block having series-connected primary and secondary check valves. The latter includes a secondary control stem having a secondary valve body and a seal. A first throttle upstream and a second throttle downstream are closed in a secondary control stem closed position where the seal tightly blocks the secondary check valve, each throttle having a tiny throttle closing gap, preferably 0.1 mm or less. The control stem can move axially into an intermediate position where the throttles remain closed, that is, have a tiny closing gap, but valve body and seal are lifted from a secondary valve seat. The control stem can be moved further into an opening position where the throttles are open, each having an opening gap much larger than the closing gap, and the valve body and seal are lifted from the valve seat.

An adjustable compact check valve for a pneumatic self-inflating mattress. The compact check valve includes a preload selector which is adjustable to user selected settings, each of which will vary the load on a preload compression spring, to thereby vary the pressure at which the check valve opens. Such adjustment allows a user to vary the firmness of a self-inflating mattress to which the compact check valve is affixed. The compact check valve also has a fully closed position, where air cannot enter or leave the self-inflating mattress, and a fully open position, where air can enter the self-inflating mattress to allow it to fully inflate, or where a user can compress the mattress for storage, by expelling air from the self-inflating mattress. Once air has been expelled from the mattress, the compact check valve may be closed, to prevent inflation of the mattress.

A hydraulic machine includes an actuator, a tank, a directional control valve disposed between the actuator and the tank, and an adjustable return check valve disposed between the directional control valve and the tank. The directional control valve includes an attachment actuator directional control valve disposed between an attachment actuator of the actuator and the tank and a swing actuator directional control valve disposed between a swing actuator of the actuator and the tank. The adjustable return check valve allows fluid to flow from the attachment actuator directional control valve toward the tank while applying the low back pressure but blocks a flow, and allows fluid to flow from the swing actuator directional control valve toward the tank while applying the high back pressure but blocks a reverse flow.

A valve assembly, comprising: a valve housing body extending along a longitudinal axis X between a first end and a second end and defining a cylindrical passage therethough from the first to the second end; a fluid inlet at the first end for receiving a pressurized fluid; and a fluid outlet provided in between the first and second end of the housing body; and a piston provided in said cylindrical passage, said piston being axially movable between a first position wherein said fluid outlet is blocked by said piston such that the piston blocks the flow of fluid from the inlet to the outlet, and a second position wherein said outlet is not blocked by said piston and a fluid flow path is formed from the inlet to the outlet.

Hydraulic fluid release valve assemblies are described herein. The hydraulic fluid release valve assemblies may include a hydraulic unit base with a hydraulic fluid return channel and a hydraulic fluid release valve that is at least partially inserted in the hydraulic fluid return channel. The hydraulic fluid release valve assembly may further include a driving assembly to contact with the hydraulic fluid release valve to apply a pushing force on the hydraulic release valve to open the hydraulic fluid release valve, and an electrically powered driver connected to the driving assembly, the electrically powered driver, when actuated, causes the driving assembly to move to apply the pushing force to the hydraulic fluid release valve.

A valve actuating assembly for actuating an internal valve between a closed position and an open position is provided. The valve actuating assembly comprises a cam holder stem securely connected to a valve body of the internal valve; a cam holder operably coupled to the cam holder stem; a cam operably mounted to the cam holder; an actuating shaft extending through at least a portion of the valve body, rotation of the actuating shaft causing rotation of the cam holder and the cam; and a locking ring configured to rotatably secure the cam holder to the cam holder stem, wherein the actuating shaft is removably coupled to the cam holder such that the actuating shaft can be removed from the valve body while the cam and cam holder remain coupled to the valve body.

A valve device (10) having a check valve mechanism (20) having a valve rod (21) and a closing element (22) disposed on one end of the valve rod (21) and intended for the compressed-air supply to a consumer (11), the valve device (10) further having an actuation mechanism (30) having a hydraulic cylinder (31), the piston (32) of the hydraulic cylinder (31) being firmly connected to the valve rod (21) and being hydraulically driven within the cylinder casing (33) of the hydraulic cylinder (31) in order to actuate the check valve mechanism (20). A control mechanism (40) for controlling the piston movement and a measuring mechanism (50) for detecting the piston position is comprised, a proportional-valve mechanism (60), which is controllable by the control mechanism (40) as a function of the piston position, being connected to the hydraulic cylinder (31) in a fluid-conducting manner. A molding machine and method for controlling a valve device are also disclosed.

Valve subassemblies include a check valve attached to a first attachment hole in a body, and an electromagnetic valve attached to a second attachment hole in the body. A second flow passage includes a common port, a linear first portion extending from the common port, a linear second portion extending from the first portion while being bent, a linear third portion connecting the first attachment hole to the second portion, and a linear fourth portion connecting the second attachment hole to the second portion. The third portion intersects the second portion at an angle equal to or smaller than 90 with respect to a first connection point of the second portion to the first portion. The fourth portion extends parallel to the second portion from an end opposite to the first connection point with respect to a second connection point of the second portion to the third portion.