Hydraulic valves for dampening pressure spikes and associated methods are disclosed herein. In one embodiment, a hydraulic valve for dampening pressure spikes includes a valve body, a poppet at least partially inside the valve body, and a pilot piston at least partially inside the valve body and away from the poppet. The pilot piston contacts the poppet in response to a pressure spike.

Valve disc assemblies for fluid valves having soft seats are disclosed herein. An example valve disc assembly for a fluid valve comprises a first portion to slidably engage a wall of the fluid valve to guide movement of the valve disc assembly and a second portion to receive a valve stem to control a position of the valve disc assembly, the second portion including an angled surface to retain a seal between the first and second portions.

A system for continuous supply of ink to a printer includes an ink tank, a supporting seat including several inkjet cartridges, and several check valves. The check valve includes a connecting tube having a first through port and a second through port, and a piston shaft movably installed in the connecting tube. The piston shaft moves to open or close the first through port. The first through port communicates with the ink tank by an ink tube and leakage of ink when the printer is lifted or when an inkhead is changed is prevented.

A flow control valve including a valve body, stepper motor, and valve member. The valve member includes a poppet that can slide longitudinally within a bore of the valve body when the stepper motor receives electricity. A diaphragm, extending inwardly from the valve body to the valve member, deflects in response to movement of the valve member. A flow control needle, mounted to the poppet of the valve member, is at least partially received in an outlet port of the valve body. The flow control needle cooperates with an inner surface of the outlet port to define an outlet flow orifice that varies in size when the valve member moves between open and closed positions. In the closed position, a seat engagement surface of the valve member contacts a valve seat of the valve body to create a fluid-tight seal.

A pressure-limiting valve for use in a gas line conveying a gas that includes aerosols. The pressure-limiting valve has a movable valve body, a valve seat, and a compressible coalescing medium placed therebetween. The valve body has passages and nozzle openings and the valve seat has through-holes. In the closed position, the valve functions in separator mode and in the fully open position, in impactor mode. The pressure-limiting valve according to the invention provides a more sensitive response to varying flow conditions, due to deviating surface profiles of the valve seat and coalescing medium, which provide intermediate stages of separator and impactor modes as a function of the volume of flow.

A pressure-limiting valve for use in a gas line conveying a gas that includes aerosols. The pressure-limiting valve has a movable valve body, a valve seat, and a compressible coalescing medium placed therebetween. The valve body has passages and nozzle openings and the valve seat has through-holes. In the closed position, the valve functions in separator mode and in the fully open position, in impactor mode. The pressure-limiting valve according to the invention provides a more sensitive response to varying flow conditions, due to deviating surface profiles of the valve seat and coalescing medium, which provide intermediate stages of separator and impactor modes as a function of the volume of flow.

A pressure relief valve having two rigid sealing surfaces lapped to a smoothness Ra of 8 micro-inches or less, and flatness within 80 micro-inches, forms a reliable seal by direct contact therebetween without an elastomer. The sealing surfaces and surrounding structures can be made of one or more metals, such as alloys of stainless steel, and can be CTE-matched, so that the valve is not impeded by environmental temperature changes. In a disclosed embodiment, a poppet is axially pressed against a seal plate by a spring. The poppet can be axially stabilized by sliding within a surrounding cylinder or spacer, and can contact the surrounding surface with a plurality of arms that reduce friction and enable gas flow therebetween. The poppet can be made from anti-galling Nitronic 60 alloy, and the surrounding structures can be stainless steel. Embodiments are suitable for low-pressure gas applications in extreme environments.

A pressure relief valve having two rigid sealing surfaces lapped to a smoothness Ra of 8 micro-inches or less, and flatness within 80 micro-inches, forms a reliable seal by direct contact therebetween without an elastomer. The sealing surfaces and surrounding structures can be made of one or more metals, such as alloys of stainless steel, and can be CTE-matched, so that the valve is not impeded by environmental temperature changes. In a disclosed embodiment, a poppet is axially pressed against a seal plate by a spring. The poppet can be axially stabilized by sliding within a surrounding cylinder or spacer, and can contact the surrounding surface with a plurality of arms that reduce friction and enable gas flow therebetween. The poppet can be made from anti-galling Nitronic 60 alloy, and the surrounding structures can be stainless steel. Embodiments are suitable for low-pressure gas applications in extreme environments.

A valve body has a piston that slides within the body through four successive positions. The piston has a head, and an upper and lower skirt, with a port in the upper skirt. In the first position, a bias force urges the piston to the first of four positions, in which the piston port is closed. In a second position, the piston port aligns with a low pressure port in the valve body, when a low pressure supply of water is connected. In a third position, greater pressure again closes the piston port. In a fourth position, at a still greater pressure, the piston port aligns with a high pressure port in the valve body. The bias force or a location of the piston port can be varied for valves along a supply line, whereby varying supply pressure opens different valves, thereby enabling addressing of valves according to supply pressure.

A hermetically sealed fuel tank system includes a hermetically sealed fuel tank, a fuel pump configured to supply fuel from within the hermetically sealed fuel tank to an internal combustion engine, and a pressure regulating valve. The pressure regulating valve is disposed within the hermetically sealed fuel tank and is configured to regulate the fuel pressure of the fuel supplied from the fuel pump to the internal combustion engine. The pressure regulating valve includes a pressure regulating chamber and a backpressure chamber partitioned by a diaphragm. An ambient air introduction passage is fluidly connected to the backpressure chamber and is configured to introduce air from the atmosphere outside the fuel tank into the backpressure chamber.