The present invention provides an electronically controlled valve in each air distribution line for delivering product-conveying air to a boom section of an agricultural machine. The valves can be used to balance airflow between lines by controlling back pressure at the boom sections. In one aspect, an electronically controlled butterfly valve can be installed in each air line between a fan's plenum outlet and a dry product delivery meter. Each valve can be configured to allow some flow when in a closed position. This could be achieved, for example, by configuring a valve plate with a circular perimeter shape that has a smaller diameter than an inner diameter of the line or tube in which the valve plate is mounted.

A poppet of a check valve includes a base, a shaft extending from the base, and a sealing head coupled to the shaft and extended away from the base by the shaft. A flow channel is defined between the base, the shaft, and the sealing head. The base includes a plurality of holes.

The invention provides a system for equalizing airflow in lines delivering product-conveying air to boom sections of an agricultural machine by controlling valves, such as electronically, in each air distribution line to induce additional pressure drops in lines which would cause imbalance in the system. Such valves can include, but are not limited to: ball valves, butterfly valves, gate valves, globe valves, diaphragm valves, pinch valves and/or plug valves. With the proposed system, the lines of least pressure drop can be induced with additional pressure drop by particular valves in order to bring the lines back to a balanced state.

A pressure relief valve is provided that includes a valve housing, a poppet valve and a damper. The valve housing includes a valve seat and a bore. The poppet valve includes a head and a stem. The head is configured to engage the valve seat when the poppet valve is in a closed position. The head is configured to disengage the valve seat when the poppet valve is in an open position. The stem projects axially out from the head and through the bore. The damper includes a damper chamber axially between the valve housing and the head.

The disclosure provides a valve core assembly and an electronic expansion valve having the valve core assembly. The valve core assembly includes: a valve head, herein an inner wall surface of the valve head is provided with a flange portion which is inwardly protruded, and the flange portion is configured to divide an inner cavity of the valve head into an upper cavity body and a lower cavity body; a screw penetrating into the valve head; and an annular member sleeved at a lower end of the screw and located in the lower cavity body, herein an upper end face of the annular member is in contact with a lower end face of the flange portion. Herein the flange portion is provided with a balancing channel, and the balancing channel connects the upper cavity body and the lower cavity body.

Provided is a linear solenoid valve having at least one notch that opens on an end surface of the land of the spool on the drain chamber side and is formed on an outer peripheral surface of the land. In response to movement of the spool, a state is formed in which the end surface of the land on the drain chamber side is located inside the communication chamber and the output chamber and the drain chamber communicate with each other via the notch and the communication chamber, and a state is formed in which the end surface of the land on the drain chamber side is located inside the output chamber and the output chamber and the drain chamber communicate with each other via the communication chamber.

An artificial sphincter includes an inflatable occlusion means for occluding a body passage, a stretchable fluid reservoir, a pump means and an occlusion means. A pressurizing fluid is selectively transferred from the occlusion means to the reservoir for deflating the occlusion means so that a blocked body passage may be opened. The artificial sphincter also includes a semipermeable check valve which always allows fluid flow towards the stretchable fluid reservoir. A semipermeable check valve allows only a restricted fluid flow from the stretchable fluid reservoir. A pressure sensitive check valve is located in between the pressure compensation balloon and the lumen of the balloon holder. The pressure sensitive check valve always allows fluid flow from the pressure compensation balloon towards the lumen so that the fluid contained in the pressure compensation balloon is freely flowable towards the inflatable occlusion means.

A valve and a method are for controlling fluid flow between a fluid supplying device and a fluid receiving device. The valve has an inlet for connection to the fluid supplying device, and an outlet. The valve has a piston arrangement slidable with respect to a valve body between a closed first position, and an open second position providing fluid communication between the inlet and the outlet upon exposure to a fluid pressure exceeding a predetermined level. The piston arrangement has a first piston area when the valve is in the closed first position, and an additional second piston area when the valve is in the open second position. The valve further has a restrictor arrangement for delaying closing of the valve to allow a fluid supply pressure to bleed off.

Various systems and methods are described for generating vacuum within an engine intake. A system may comprise an intake throttle including a throttle plate, where the throttle plate may comprise a hollow interior passage, which in turn may be coupled to a vacuum consumption device. When vacuum is demanded by the vacuum consumption device, the throttle plate may be adjusted to increase airflow through the interior passage and vacuum may be generated at a constricted portion of the interior passage by flowing intake air through the interior passage of the throttle plate.

A variable flow check valve device is proposed comprising an inlet connected with a first pressure fluid reservoir, an outlet connected with a second pressure fluid reservoir, which is separate and/or separable from the first pressure fluid reservoir, a check valve closing member configured to open and to close the outlet in response to a pressure difference of the pressure fluid on opposite sides of the check valve closing member, and a spool valve with a movable spool disposed in a flow path of the pressure fluid extending from the inlet to the outlet, the spool valve forming a variable orifice within the flow path of the pressure fluid, wherein the variable flow check valve device further comprises a force balancing unit disposed in the flow path of the pressure fluid and configured to create a balancing force to at least partially counteract a force acting on the spool when the pressure fluid passes the at least partially opened spool valve.