A device for protecting an electric pump against overpressures, which comprises a main body which forms a cavity with an axis of extension which is substantially parallel to an axis of extension of the main body and a flow control element which can slide in the cavity along the axis of extension of the cavity between a closed position, in which the flow control element affects an inlet of the cavity which can be connected fluidically to a delivery port of an electric pump, and an open position, in which the flow control element clears at least partially the inlet so as to place it in fluidic connection with an outlet of said cavity, elastic means designed to push the flow control element in response to the pressure that is present in the delivery port.

A device for protecting an electric pump against overpressures, which comprises a main body which forms a cavity with an axis of extension which is substantially parallel to an axis of extension of the main body and a flow control element which can slide in the cavity along the axis of extension of the cavity between a closed position, in which the flow control element affects an inlet of the cavity which can be connected fluidically to a delivery port of an electric pump, and an open position, in which the flow control element clears at least partially the inlet so as to place it in fluidic connection with an outlet of said cavity, elastic means designed to push the flow control element in response to the pressure that is present in the delivery port.

A self-priming assembly for a multi-stage pump is provided. The self-priming assembly can have a first diffuser, a second diffuser, and an impeller. The first and second diffusers each include a central portion, a diffuser axis, an arcuate channel within the central portion, and a passage extending through the central portion. The first diffuser and the second diffuser are configured to be combined and receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned.

A self-priming assembly for a multi-stage pump is provided. The self-priming assembly can have a first diffuser, a second diffuser, and an impeller. The first and second diffusers each include a central portion, a diffuser axis, an arcuate channel within the central portion, and a passage extending through the central portion. The first diffuser and the second diffuser are configured to be combined and receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned.

The application discloses a multipurpose transfer pump free of secondary water filling, which comprises a cover plate, a water filling plug, a pump body, an impeller, a pump body flange and a motor, the pump body flange is provided at an end portion of the motor, the pump body is provided on a front surface of the pump body flange, a volute chamber corresponding to the impeller is provided in a back surface of the pump body in an inwards recessed manner. In this way, the multipurpose transfer pump free of secondary water filling disclosed by the application can achieve a self-priming effect without filling water into the pump body when the motor works for a second time, thus improving the impeller lubricating effect.

The present invention provides a quick startup device for a centrifugal pump. The device includes an upper self-priming chamber, a lower self-priming chamber, and an inlet pipe sequentially arranged from top to bottom. The upper self-priming chamber and the lower self-priming chamber are integrally mounted on the inlet pipe. A main shaft and a hexagonal partition member rotatably mounted on the main shaft are arranged on an axis of the upper self-priming chamber. A blade tip of each partition plate is closely attached to an inner wall surface of the upper self-priming chamber. Three identical accommodation grooves are provided on an inner side of the upper self-priming chamber. A spring and a separation baffle are arranged in each accommodation groove, an exhaust hole is provided on one side of each accommodation groove, and an air intake pipe is provided on the other side of each accommodation groove.

The present invention provides a quick startup device for a centrifugal pump. The device includes an upper self-priming chamber, a lower self-priming chamber, and an inlet pipe sequentially arranged from top to bottom. The upper self-priming chamber and the lower self-priming chamber are integrally mounted on the inlet pipe. A main shaft and a hexagonal partition member rotatably mounted on the main shaft are arranged on an axis of the upper self-priming chamber. A blade tip of each partition plate is closely attached to an inner wall surface of the upper self-priming chamber. Three identical accommodation grooves are provided on an inner side of the upper self-priming chamber. A spring and a separation baffle are arranged in each accommodation groove, an exhaust hole is provided on one side of each accommodation groove, and an air intake pipe is provided on the other side of each accommodation groove.

A self-priming assembly for a multi-stage pump is provided. The self-priming assembly includes a first diffuser with a first central portion, a first diffuser axis, a first arcuate channel within the first central portion, and a first arcuate passage extending through the first central portion and a first peripheral portion having a first ledge. The self-priming assembly also includes a second diffuser with a second central portion, a second diffuser axis, a second arcuate channel within the second central portion, a second arcuate passage extending through the second central portion, and a second peripheral portion having a second ledge. The first ledge abuts the second ledge. Further, the self-priming assembly includes an impeller with an impeller axis. The first diffuser and the second diffuser are configured to be combined and to receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned.

A self-priming assembly for a multi-stage pump is provided. The self-priming assembly includes a first diffuser with a first central portion, a first diffuser axis, a first arcuate channel within the first central portion, and a first arcuate passage extending through the first central portion and a first peripheral portion having a first ledge. The self-priming assembly also includes a second diffuser with a second central portion, a second diffuser axis, a second arcuate channel within the second central portion, a second arcuate passage extending through the second central portion, and a second peripheral portion having a second ledge. The first ledge abuts the second ledge. Further, the self-priming assembly includes an impeller with an impeller axis. The first diffuser and the second diffuser are configured to be combined and to receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned.

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.