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 water pump has a check valve with a valve body movable in a direction of a valve axis of the check valve between an open position of the check valve and a closed position of the check valve. An actuating device is connected with the check valve and has an operating element that is movable coaxially to the valve axis. The operating element is operatively connected to the valve body and arranged such that the operating element, by applying a coaxial force to the valve body, transfers the valve body into a venting position of the check valve.

Centrifugal pumps are widely used in swimming pools as part of the recirculation system that sucks water from the swimming pool through the drain and them pumps it back into the pool after filtration. The present invention relates to a centrifugal pump for swimming pools that can accommodate impellers of varying size to attain the proper flow rate for varying circumstances. The centrifugal pump of the present invention also includes a deflector that improves the priming of the pump so as to eliminate or reduce the risk of heat and friction damage to the impeller.

A well fluid centrifugal pump has a shaft passage in the shaft. The shaft passage has an open upper end above the impellers and a closed lower end below the impellers. An outlet port extends laterally from the shaft passage. A gas-lock re-priming device in the shaft passage diverts a portion of well fluid in the discharge adapter bore through the shaft passage and out the outlet port. The re-priming device may be a pressure actuated valve that is biased to a closed position and opens when the pressure in the discharge adapter bore drops below a minimum. Alternately, the re-priming device may be an orifice member with an orifice passage that continuously diverts a portion of the well fluid in the discharge adapter bore out the outlet port.

A sand fallback tool having an outer tubular body with proximal end, a distal end, a chamber therebetween surrounding an axis extending from the proximal end through the distal end, a tubular flow divider supported within the chamber to divide at least a portion of the chamber of the outer tubular body into a central passage along the axis and an annular passage radially intermediate an exterior of the tubular flow divider and an interior of the outer tubular body, and an unobstructed axial settling path from the proximal connector into the central passage. One embodiment further includes a tubular extension coupled to the proximal connector and extending along the axis to terminate at a distal end of the tubular extension received within a proximal end of the tubular flow divider to provide an “S”-shaped flow pathway intermediate the annular passage and the proximal connector of the outer tubular body.

A sand fallback tool having an outer tubular body with proximal end, a distal end, a chamber therebetween surrounding an axis extending from the proximal end through the distal end, a tubular flow divider supported within the chamber to divide at least a portion of the chamber of the outer tubular body into a central passage along the axis and an annular passage radially intermediate an exterior of the tubular flow divider and an interior of the outer tubular body, and an unobstructed axial settling path from the proximal connector into the central passage. One embodiment further includes a tubular extension coupled to the proximal connector and extending along the axis to terminate at a distal end of the tubular extension received within a proximal end of the tubular flow divider to provide an “S”-shaped flow pathway intermediate the annular passage and the proximal connector of the outer tubular body.

There is provided a centrifugal pump comprising a pumping chamber (106). The pumping chamber (106) has an inner surface (108) defining a pump cavity (110); a pump inlet (112) defined in a first side of the pumping chamber (106); a shaft opening (116) defined substantially centrally in a second side of the pumping chamber (106), the second side substantially opposing the first side and arranged to be above the first side, in use; and a pump outlet (114). The centrifugal pump further comprises an impeller (120) retained within the pump cavity (110); and a shaft member (140) mechanically connected to the impeller (120) through the shaft opening (116), whereby rotation of the shaft member (140) causes rotation of the impeller (120) about a shaft axis (157) passing through the shaft opening (116) and movement of a pumping liquid from the pump inlet (112) towards the pump outlet (114). The centrifugal pump further comprises a flow modifier (150) provided adjacent to an outer surface (107) of the pumping chamber (106) at the shaft opening (116) to substantially prevent ingress of air into the pump cavity (110) through the shaft opening (116) during operation of the pump even when a water level in a liquid tank (104) surrounding the pumping chamber (106) drops below a level of the shaft opening (116). The flow modifier (150) comprises an annular portion (152) having defined therein a further shaft opening (156) spaced from the shaft opening (116) and having the shaft member (140) passing therethrough. The centrifugal pump comprises a spacing member (154) spacing the annular portion (152) from the outer surface (107). The flow modifier (150) defines a liquid overflow outlet (164) for liquid flow from the shaft opening (116) in a direction substantially transverse to the shaft axis (157). In one example, the liquid overflow outlet (164) is sized to substantially prevent the ingress of air into the pump cavity (110) through the shaft opening (116) during operation of the pump, even when the water level in the liquid tank (104) surrounding the pumping chamber (106) drops below the level of the shaft opening (116). In the same or an alternative example, the annular portion (152) comprises a first portion (158) having defined therein the further shaft opening (156) and a second portion (160) extending towards the outer

A well fluid centrifugal pump has a shaft passage in the shaft. The shaft passage has an open upper end above the impellers and a closed lower end below the impellers. An outlet port extends laterally from the shaft passage. A gas-lock re-priming device in the shaft passage diverts a portion of well fluid in the discharge adapter bore through the shaft passage and out the outlet port. The re-priming device may be a pressure actuated valve that is biased to a closed position and opens when the pressure in the discharge adapter bore drops below a minimum. Alternately, the re-priming device may be an orifice member with an orifice passage that continuously diverts a portion of the well fluid in the discharge adapter bore out the outlet port.

There is provided a centrifugal pump comprising a pumping chamber (106). The pumping chamber (106) has an inner surface (108) defining a pump cavity (110); a pump inlet (112) defined in a first side of the pumping chamber (106); a shaft opening (116) defined substantially centrally in a second side of the pumping chamber (106), the second side substantially opposing the first side and arranged to be above the first side, in use; and a pump outlet (114). The centrifugal pump further comprises an impeller (120) retained within the pump cavity (110); and a shaft member (140) mechanically connected to the impeller (120) through the shaft opening (116), whereby rotation of the shaft member (140) causes rotation of the impeller (120) about a shaft axis (157) passing through the shaft opening (116) and movement of a pumping liquid from the pump inlet (112) towards the pump outlet (114). The centrifugal pump further comprises a flow modifier (150) provided adjacent to an outer surface (107) of the pumping chamber (106) at the shaft opening (116) to substantially prevent ingress of air into the pump cavity (110) through the shaft opening (116) during operation of the pump even when a water level in a liquid tank (104) surrounding the pumping chamber (106) drops below a level of the shaft opening (116). The flow modifier (150) comprises an annular portion (152) having defined therein a further shaft opening (156) spaced from the shaft opening (116) and having the shaft member (140) passing therethrough. The centrifugal pump comprises a spacing member (154) spacing the annular portion (152) from the outer surface (107). The flow modifier (150) defines a liquid overflow outlet (164) for liquid flow from the shaft opening (116) in a direction substantially transverse to the shaft axis (157). In one example, the liquid overflow outlet (164) is sized to substantially prevent the ingress of air into the pump cavity (110) through the shaft opening (116) during operation of the pump, even when the water level in the liquid tank (104) surrounding the pumping chamber (106) drops below the level of the shaft opening (116). In the same or an alternative example, the annular portion (152) comprises a first portion (158) having defined therein the further shaft opening (156) and a second portion (160) extending towards the outer

Centrifugal pumps are widely used in swimming pools as part of the recirculation system that sucks water from the swimming pool through the drain and them pumps it back into the pool after filtration. The present invention relates to a centrifugal pump for swimming pools that can accommodate impellers of varying size to attain the proper flow rate for varying circumstances. The centrifugal pump of the present invention also includes a deflector that improves the priming of the pump so as to eliminate or reduce the risk of heat and friction damage to the impeller.