An oil returning valve set with multi-stage throttling control includes an oil returning channel implemented in oil in an oil hydraulic equipment. The two ends of the oil returning channel are connected to a pressurized oil collecting cavity and a pressurized oil discharging cavity respectively. A plurality of throttling valve plugs and oil returning valve plug are arranged in the oil returning channel, and a normally-open draining gap is also formed among the plurality of throttling valve plugs. When the oil returning valve plug is opened, a plurality of the throttling valve plugs are arranged in series to generate multi-stage throttling oil hydraulic draining control, which improves the problem that the valve opening allowance of the throttling valve for oil returning and pressure relief of traditional oil hydraulic equipment is not sufficient.

A hydraulic valve includes a valve housing, a valve cone, a spring housing, a check valve, a first hydraulic connection and a second hydraulic connection. The valve housing has a valve seat and the valve cone is movable in the valve housing between a closed position and an open position. In the closed position, the valve cone is in contact with the valve seat and blocks a first flow path between the first and the second hydraulic connection. In the open position, the valve cone is lifted off the valve seat and the first flow path is opened. A spring element is disposed in the spring housing, which biases the valve cone into the closed position. The check valve is disposed in the valve cone and opens a second flow path from the second hydraulic connection to the first hydraulic connection when pressure is applied to the second hydraulic connection.

The present invention relates to a fluid control system comprising a first chamber, a second chamber and a passage extending between said upstream chamber and said downstream chamber. An elongate valve spool core (8) is moveable arranged in passage in a fluid-tight and snug-fit manner, the spool core containing a groove (9). An actuator (18) typically connected to the elongated valve spool core to move the valve spool core in relation passage. Thereby a flow rate of a fluid flowing from the upstream chamber to the downstream chamber may be changed by moving the spool core relative to the passage to increase an orifice area.

A valve device that includes a first valve body including an opening; a second valve body arranged within the first valve body and movable relative to the first valve body; a first valve seat arranged around an opening of a valve chamber, wherein the first valve body contacts the first valve seat; a second valve seat arranged around the opening of the first valve body, wherein the second valve body contacts the second valve seat; a piston applying a force to the second valve body by contacting the second valve body such that the second valve body is separated from the second valve seat; a movement restricting member fixed to the first valve body and restricting a movement of the second valve body in an axial direction relative to the first valve body; and a rotation restricting member restricting rotation of the first valve body relative to the second valve body.

A vent having a vent housing defining a mounting structure, a first opening between a first end and a second end of the vent housing, a first airflow pathway from the first opening, a second airflow pathway from a second opening, and a draining pathway from the first airflow pathway through the first end of the vent housing. The first airflow pathway has a first segment and a second segment extending in opposite axial directions. An inlet relief valve and an outlet relief valve are arranged in parallel between the first and second airflow pathways. The inlet relief valve opens upon exceeding a first threshold pressure differential of the second relative to the first airflow pathway. The outlet relief valve opens upon exceeding a second pressure differential of the first relative to the second airflow pathway. A filter assembly is disposed in the vent housing across the second airflow pathway.

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.

An on-off valve that operates between an open position and a closed position, particularly with high-pressure working fluids, has a valve body that defines a valve cavity having a first chamber and a second chamber. A valve poppet is slidably mounted within the valve cavity. The valve poppet has a larger first end positioned within the first chamber and a smaller second end positioned within the second chamber. The valve poppet has a fluid seal around the first end and a second fluid seal around the second end. Each fluid seal is isolated in the space between the seals and the space is connected to the atmosphere. A pilot control valve is fluidly connected to the first chamber of the valve body and sends a control fluid or working fluid in and out of the first chamber and moves the valve poppet between the open position and the closed position. The pilot valve has a control tube or control rod having fluid passages made on or inside the control rod. The control rod is positioned inside a cylindrical cavity and the cavity has rod seals and bushings that define 3 separate fluid chambers, including an inlet chamber, an exit chamber and a cocking chamber. The inlet chamber is fluidly connected to the source of the control fluid. The exit chamber is fluidly connected to the exterior of the pilot valve. The cocking chamber of the control rod cavity is fluidly connected to the first chamber of the main valve. The control rod can be moved with an outside force to a first position and to a second position such that the main valve will be open when the control rod is at its first position and the main valve will be closed when the control rod is at its second position. The pilot valve can be mounted inside or outside of the main valve. The pilot valve can also be integrated into the valve poppet to form a valve cartridge for a simplified valve construction.

An interposed coaxial valve system designed for internal combustion engines. The system comprises a single main valve integrating two coaxial valves: an interior valve and an exterior valve. The interior valve may move independently from the exterior valve during engine operation. The system minimizes spatial occupancy for internal combustion engine valves. By interposing the interior valve within the exterior valve, the system achieves a compact and efficient design. The system may also comprise adjacent intake and exhaust ports to promote heat transfer between the two ports.

A hydraulic valve includes a valve housing, a valve cone, a spring housing, a check valve, a first hydraulic connection and a second hydraulic connection. The valve housing has a valve seat and the valve cone is movable in the valve housing between a closed position and an open position. In the closed position, the valve cone is in contact with the valve seat and blocks a first flow path between the first and the second hydraulic connection. In the open position, the valve cone is lifted off the valve seat and the first flow path is opened. A spring element is disposed in the spring housing, which biases the valve cone into the closed position. The check valve is disposed in the valve cone and opens a second flow path from the second hydraulic connection to the first hydraulic connection when pressure is applied to the second hydraulic connection.

A fluidic device comprises an inlet and an outlet connected by a body forming a channel between the inlet and the outlet. The fluidic device further comprises a non-return valve shaped to prevent a fluid from passing from the outlet to the inlet, and a flow restrictor shaped to allow a fluid to pass from the inlet to the outlet at a first flow rate when the differential pressure between the outlet and the inlet is below a threshold(S). Fluid passes from the inlet to the outlet at a second flow rate, significantly lower than the first flow rate, when the differential pressure between the outlet and the inlet is above the threshold.