A dispenser includes a housing, an inverted container disposed in the housing, a outlet nozzle, a pump, a first check valve, and a second check valve. The pump is disposed between the container and the outlet nozzle. The pump includes a pump inlet a pump outlet, and a pump chamber. The pump chamber is movable between an expanded position and a compressed position. The first check valve is disposed between the pump and the outlet nozzle, and the first check valve has a first cracking pressure. The second check valve is disposed between the first check valve and the outlet nozzle, and the second check valve has a second cracking pressure. The second cracking pressure of the second check valve is greater than the first cracking pressure of the first check valve.

A check valve (1) which comprises an obturator (2) and a biasing mechanism, the biasing mechanism arranged to urge the obturator towards a closed condition, and the check valve further comprising an actuator assembly (5, 7a, 7b) which is arranged to be selectively activated to cause the obturator to be in an open condition, and the check valve comprising a controller which has a control signal input to cause the controller to selectively activate the actuator assembly.

A flow arrangement for a pressure relief valve assembly can include a bypass flow path extending from a pressure source to a dome of a relief valve. The bypass flow path can include a valve that is configured to open and close the bypass flow path based on pressure at the pressure source or the dome, or a pressure difference between the pressure source and the dome.

A hydrant valve with an internal automatic shut-off valve. The internal valve blocks communication between a piston chamber and a hydrant chamber when in a closed position. An upper valve opens the internal valve against its biasing force permitting the flow of fluid between the hydrant chamber and the piston chamber. The internal valve closes in response to a disconnection of the upper valve.

A valve assembly includes a housing, a collar, a sheath fixedly coupled to the collar, and a stem assembly. The collar and the sheath can be axially moveable relative to the housing between a first position, a second position, and a third position. In the first position, a fluid inside a lumen of the housing can be blocked from flowing into a lumen of the collar. In the second position, the fluid inside the lumen of the housing can flow through the lumen of the collar and into a chamber of the sheath. The fluid can be retained therein or flow out of the sheath through an aperture when the sheath is selectively deformed. In the third position, the fluid inside the lumen of the housing can flow through the lumen of the collar and the chamber, and then flow out of the sheath unobstructed through the aperture.

A modulating intake valve having a low internal pressure drop used in conjunction with a gas compressor, including a valve body having a gas inlet and a gas outlet. A self modulating, hemispherical shaped poppet within the valve body moves closer or further from a valve seat to control the gas flow into the inlet and out of the outlet into the gas compressor. The hemispherical poppet valve functions as a check valve to close against the valve seat and prevent flow of gas and oil from the compressor through the valve body and out of the gas inlet. A modulating piston disposed in a cage located between the gas inlet and the gas outlet. A control gas inlet port opens into a passageway to direct control gas to a space between the piston and the cage set to move the piston and hemispherical poppet valve at a given pressure.

A vacuum electrically controlled proportional valve includes a valve seat coupled to a guide seat. The guide seat is connected, at a top thereof, to a vacuum pressure electromagnetic valve, an atmospheric pressure electromagnetic valve, and a sensor. A main diaphragm is sandwich between the seat valve and the guide seat to define a vacuum pressure chamber. A pilot discharge straight rod that is provided with a vacuum valve gate assembly is fit to a center of the main diaphragm. A master channel through which a primary-side pressure and a secondary-side pressure flow is provided. A regulation channel is provided and controlled by the vacuum pressure electromagnetic valve and the atmospheric pressure electromagnetic valve. A pilot atmosphere channel is connected to a space under the main diaphragm. A first and a second vacuum destruction valve gates are provided for adjusting, in stage-wise manner, the level of vacuum pressure.

A valve assembly includes a flange connected to a vessel penetration of a reactor pressure vessel of a nuclear reactor. A valve is disposed inside the flange or protrudes from the flange into the vessel penetration. The valve includes a valve seat and a movable valve member positioned so that pressure inside the reactor pressure vessel urges the movable valve member against the valve seat to close the valve. The valve assembly further includes a plenum having an inlet via which the plenum can be pressurized to apply pressure to the movable valve member that urges the movable valve member away from the valve seat to open the valve. The plenum may be defined in part by a surface of the movable valve member. The valve assembly preferably does not include a valve actuator.

Systems for chemical injection. An example system includes a pilot valve comprising: a hydraulic piston, a poppet, and a biasing device. The system further comprises a jay-selector comprising: a rotatable jay-piston having jay-slots, and a plurality of ports. The system additionally comprises a plurality of flow restrictors.

A valve for pressurized gas or chemical agent. The valve comprises: a body with: an inlet, an outlet, and a passage which connects the inlet with the outlet and which includes a seat]. The valve further comprises a sliding piston able to engage with the seat in order to close the passage and a telescopic extension sliding against the passage in order to guide the piston in the passage at least between the open position and the closed position. The pressure difference between opposite faces of the piston pulls away the piston and the telescopic extension from the seat in order to open the passage, the passage remaining closed under pressure equilibrium. Additionally, a fire extinguishing system.