The present invention claims a vertical self-priming pump which comprises a pump body, a motor and a medium backflow blocking device, the medium backflow blocking device comprises a static ring and a moving ring which are vertically and oppositely arranged, and an elastic supporting sleeve; the moving ring is embedded on the upper surface of the impeller, the elastic supporting sleeve is fixed on the upper surface of the flow guide body, and the static ring is embedded on the lower surface of an elastic supporting ring. During normal working, the elastic supporting sleeve of the present invention in the medium backflow blocking device generates a downward deformation under the action of liquid medium pressure, thus the moving ring and the static ring closely contact with each other and block the backflow gap channel, and the pump efficiency is improved.

A pump has a main body. An assembling part is formed in the main body and has an assembling chamber. A mounting part is formed in the assembling chamber and has a discharging chamber. An influent hole and an effluent hole are respectively defined through an inner surface of the discharging chamber. A storage hole is defined through the assembling chamber and communicates with the effluent hole. A mounting cover is mounted on the mounting part. A motor is mounted on the main body. An impeller is located in the discharging chamber and connected with the motor. A covering assembly is mounted on the assembling part and has a storage chamber that communicates with the storage hole. When working fluid passes through the effluent hole, some of the working fluid enters the storage chamber via the storage hole, eliminating the need to additionally process the mounting cover.

A centrifugal pump (7), with one or more pumping stages, includes a pressure controlled valve (15) inside the pump (7) for supporting self-priming, the pressure controlled valve (15). The pressure controlled valve (15) includes a pretensioned leaf spring (17) and a valve seat (18). The leaf spring (17) has an opened position and a closed position. In the open position the leaf spring (17) is distanced from the valve seat (18). In the closed position the leaf spring (17) closes the valve seat (18). The leaf spring (17) and valve seat (18) are arranged for soft closing.

A centrifugal pump (7), with one or more pumping stages, includes a pressure controlled valve (15) inside the pump (7) for supporting self-priming, the pressure controlled valve (15). The pressure controlled valve (15) includes a pretensioned leaf spring (17) and a valve seat (18). The leaf spring (17) has an opened position and a closed position. In the open position the leaf spring (17) is distanced from the valve seat (18). In the closed position the leaf spring (17) closes the valve seat (18). The leaf spring (17) and valve seat (18) are arranged for soft closing.

Technologies are generally described for pump devices that include an adaptive cutwater and impeller arrangement. The power end of the pump device can be coupled to a motor to drive an impeller. The primer plate and impeller of the pump device are removable from the pump casing such that the primer plate and impeller can be replaced or modified as desired for different applications. In some examples, the pump casing includes a primer plate that is removable from the pump casing, where the primer plate includes a discharge cutwater tongue that is specifically spaced and sized to service an impeller of a desired design. The discharge cutwater tongue and impellers in the pump device may thus be serviced for replacement parts, as well as to modify the pump device for different fluids of different fluids properties or hydraulic requirements as may be needed in different applications.

Technologies are generally described for pump devices that include an adaptive cutwater and impeller arrangement. The power end of the pump device can be coupled to a motor to drive an impeller. The primer plate and impeller of the pump device are removable from the pump casing such that the primer plate and impeller can be replaced or modified as desired for different applications. In some examples, the pump casing includes a primer plate that is removable from the pump casing, where the primer plate includes a discharge cutwater tongue that is specifically spaced and sized to service an impeller of a desired design. The discharge cutwater tongue and impellers in the pump device may thus be serviced for replacement parts, as well as to modify the pump device for different fluids of different fluids properties or hydraulic requirements as may be needed in different applications.

A centrifugal pump to improve the efficiency of fluid flow, and minimize long term wear on the pump by progressively increasing fluid pressure as fluid moves from an eye of an impeller towards diffuser blades, into the volute and out through an outlet. The fluid pressure is increased by progressively increasing the volume through which the fluid travels. A tear-drop shaped volute casing surrounding the diffuser and impeller creates a pocket of maximum pressure just below the outlet. A dampener can be provided to dampen the vibration of the motor. A cylindrical basket strainer can be provided with a flat face abutting against the volute casing to distribute pressure evenly. A clamp ring can be provided to easily seal and access the basket strainer using a plain rod.

A centrifugal pump to improve the efficiency of fluid flow, and minimize long term wear on the pump by progressively increasing fluid pressure as fluid moves from an eye of an impeller towards diffuser blades, into the volute and out through an outlet. The fluid pressure is increased by progressively increasing the volume through which the fluid travels. A tear-drop shaped volute casing surrounding the diffuser and impeller creates a pocket of maximum pressure just below the outlet. A dampener can be provided to dampen the vibration of the motor. A cylindrical basket strainer can be provided with a flat face abutting against the volute casing to distribute pressure evenly. A clamp ring can be provided to easily seal and access the basket strainer using a plain rod.

An impeller includes a disk-shaped hub and a plurality of vanes provided radially on the surface of the hub. The plurality of vanes are formed in a whirling pattern about the center of rotation of the impeller, and each of the vanes has an outer peripheral surface facing the inner peripheral surface of the volute. A rotational-direction rear end portion of the outer peripheral surface of each of the vanes has a recessed step surface formed thereon. The rotational-direction rear end of the recessed step surface of each of the vanes is formed to define an edge shape with respect to a rotational-direction rear end surface of the vane.

An impeller includes a disk-shaped hub and a plurality of vanes provided radially on the surface of the hub. The plurality of vanes are formed in a whirling pattern about the center of rotation of the impeller, and each of the vanes has an outer peripheral surface facing the inner peripheral surface of the volute. A rotational-direction rear end portion of the outer peripheral surface of each of the vanes has a recessed step surface formed thereon. The rotational-direction rear end of the recessed step surface of each of the vanes is formed to define an edge shape with respect to a rotational-direction rear end surface of the vane.