A valve unit for pumps includes a first chamber communicating with an inlet conduit and with a discharge conduit, a second chamber communicating with the first via a first valve seat and with an outlet conduit. A first obturator body housed within the second chamber opens and closes the first valve seat. A third chamber communicates with the second chamber and partially defined by a sliding plunger. A second obturator body, rigidly connected to the plunger and housed within the first chamber, opens and closes the second valve seat. An internal cavity in the second obturator body communicates with the first chamber, a connection conduit in the second obturator body, communicates with the discharge conduit and with the internal cavity via a third valve seat. A third obturator body housed within the internal cavity of the second obturator body opens and closes the third valve seat.

A valve unit for pumps includes a first chamber communicating with an inlet conduit and with a discharge conduit, a second chamber communicating with the first via a first valve seat and with an outlet conduit. A first obturator body housed within the second chamber opens and closes the first valve seat. A third chamber communicates with the second chamber and partially defined by a sliding plunger. A second obturator body, rigidly connected to the plunger and housed within the first chamber, opens and closes the second valve seat. An internal cavity in the second obturator body communicates with the first chamber, a connection conduit in the second obturator body, communicates with the discharge conduit and with the internal cavity via a third valve seat. A third obturator body housed within the internal cavity of the second obturator body opens and closes the third valve seat.

A pneumatic pump having an overpressure protection valve having a gasket and spring that includes a diaphragm carrier, a diaphragm member, a valve base, a valve, a cap, a driving device and an overpressure protection valve is revealed. A pump chamber is formed between the diaphragm member and the valve base. The overpressure protection valve having a spring and a gasket. A discharge channel, an air-flow channel and a backflow channel are formed among the pump chamber, the valve base, the valve and the cap. The discharge channel, the overpressure protection valve and the spring chamber are separated. The gasket is disposed between the air-flow channel and the backflow channel for closing the air-flow channel normally. The driving device drives the diaphragm member for discharging air from the pump chamber through the discharge channel.

A pneumatic pump having an overpressure protection valve having a gasket and spring that includes a diaphragm carrier, a diaphragm member, a valve base, a valve, a cap, a driving device and an overpressure protection valve is revealed. A pump chamber is formed between the diaphragm member and the valve base. The overpressure protection valve having a spring and a gasket. A discharge channel, an air-flow channel and a backflow channel are formed among the pump chamber, the valve base, the valve and the cap. The discharge channel, the overpressure protection valve and the spring chamber are separated. The gasket is disposed between the air-flow channel and the backflow channel for closing the air-flow channel normally. The driving device drives the diaphragm member for discharging air from the pump chamber through the discharge channel.

A method of operating a system (16) for pumping a fluid, which system comprises a pump (17) comprising a suction side (18) and a discharge side (19); a motor (20) for driving the pump, which motor is drivingly connected to the pump via a shaft; a recirculation conduit (23) providing a fluid path for the fluid from the discharge side to the suction side of the pump; and a control valve controlling the flow of the fluid through the recirculation conduit, which method comprises the steps of: mapping a plurality of minimum torque diagrams for the pump, where each minimum torque diagram identifies the minimum allowable torque of the pump as a function of an operational parameter of the pump, e.g. the differential pressure over the pump; from said plurality of minimum torque diagrams, identifying the minimum torque diagram best representing the current operation of the pump; monitoring said operational parameter of the pump and, from the minimum torque diagram best representing the current operation of the pump, identifying a minimum allowable torque value corresponding to a monitored value of said operational parameter of the pump, e.g. a monitored differential pressure value; monitoring the torque of the pump and comparing a monitored torque value with the identified minimum allowable torque value; and regulating the control valve such that the monitored torque value does not fall below the minimum allowable torque value. A corresponding pumping system is also disclosed.

A miniature fluid transportation device is provided and includes a convergence component, a valve component, an outlet plate and a plurality of fluid transportation actuation components. The plurality of fluid transportation actuation components are disposed on the convergence component so as to transport the fluid to the convergence component. The convergence component guides the fluid transported by the fluid transportation actuation components to the outlet plate through the valve component. The outlet plate guides the fluid from different transportation actuation components back to the convergence component by a separation guiding block. The fluid is converged in a convergence central slot of the convergence component and is discharged out through a collection channel of the outlet plate. Consequently, the problem of interference owing to the convergence of the fluid transported by different fluid transportation actuation components can be avoided.

A miniature fluid transportation device is provided and includes a convergence component, a valve component, an outlet plate and a plurality of fluid transportation actuation components. The plurality of fluid transportation actuation components are disposed on the convergence component so as to transport the fluid to the convergence component. The convergence component guides the fluid transported by the fluid transportation actuation components to the outlet plate through the valve component. The outlet plate guides the fluid from different transportation actuation components back to the convergence component by a separation guiding block. The fluid is converged in a convergence central slot of the convergence component and is discharged out through a collection channel of the outlet plate. Consequently, the problem of interference owing to the convergence of the fluid transported by different fluid transportation actuation components can be avoided.

An air compression pump includes a pump head and a pumping device fluidly connected with the pump head. The pumping device includes a cylinder fixed to the pump head. Further, a relief valve is fluidly connected with and received by the pump head. The relief valve defines a relief hole which is fluidly communicable with the first cylinder. The relief valve includes a valve body selectively closing the relief hole. The valve body is movable to an open position to relieve pressure in the air compression pump by allowing pressurized air to flow out of the air compression pump through the relief hole.

An air compression pump includes a pump head and a pumping device fluidly connected with the pump head. The pumping device includes a cylinder fixed to the pump head. Further, a relief valve is fluidly connected with and received by the pump head. The relief valve defines a relief hole which is fluidly communicable with the first cylinder. The relief valve includes a valve body selectively closing the relief hole. The valve body is movable to an open position to relieve pressure in the air compression pump by allowing pressurized air to flow out of the air compression pump through the relief hole.

A high-pressure pump includes a pressurizing chamber forming portion including a cylindrical inner peripheral wall that defines a pressurizing chamber, a plunger, a housing including a housing outer peripheral wall, a valve member, an electromagnetic driving unit, a discharge passage portion, and a fixed portion that is connected to the housing. The fixed portion has multiple bolt holes. The multiple bolt holes are arranged radially outward of the housing outer peripheral wall in a circumferential direction when viewed along a direction of an axis of the cylindrical inner peripheral wall. The high-pressure pump is virtually divided into a first region and a second region by a virtual surface on which axes of adjacent ones of the multiple bolt holes and an axis of the cylindrical inner peripheral wall extend. Both the electromagnetic driving unit and the discharge passage portion are located in the first region or the second region.