A pressure-controlling device (10) includes a pump (21), a connection pipe (30), a first valve (41), and a second valve (42). The pump (21) has an inlet port (211) and an outlet port (212). The connection pipe (30) has a first end in communication with the outlet port (212), and a second end in communication with the inlet port (211) and that has a first space (31) that contains the first end, a second space (32) that contains the second end, and a third space (33) that is located between the first space (31) and the second space (32).

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 debris trap for capturing debris flowing in a stream of liquid, the debris trap includes a housing, a fluid inlet channel in connection with a space in the housing, a fluid outlet channel in connection with the space, the fluid outlet channel comprising a fluid outlet port, a float member, a guide element configured to guide movement of the float member when a liquid level in the space changes when in use, a stopper in connection with the fluid outlet port configured to stop the movement of the float member when the liquid level in the space raises, the fluid outlet port which, when the float member is against the stopper, remains partially open and the float member, when brought against the stopper, form a fluid communication path with a reduced area, which restricts the size of the debris capable of flowing through the outlet port.

A debris trap for capturing debris flowing in a stream of liquid, the debris trap includes a housing, a fluid inlet channel in connection with a space in the housing, a fluid outlet channel in connection with the space, the fluid outlet channel comprising a fluid outlet port, a float member, a guide element configured to guide movement of the float member when a liquid level in the space changes when in use, a stopper in connection with the fluid outlet port configured to stop the movement of the float member when the liquid level in the space raises, the fluid outlet port which, when the float member is against the stopper, remains partially open and the float member, when brought against the stopper, form a fluid communication path with a reduced area, which restricts the size of the debris capable of flowing through the outlet port.

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.

A centrifugal pump with a barrel casing and a ventilation arrangement is provided. A plug-in unit is arranged in the barrel casing. The plug-in unit has a shaft, and at least one impeller is arranged on the shaft. The impeller is enclosed by a stage casing. The stage casing separates an inner pressure space from an outer pressure space. At least one venting device is arranged in the stage casing.

A quick no-water startup apparatus for a centrifugal pump includes, from top to bottom in sequence, one-way passages (1), a self-priming chamber housing (41), sliding devices (5), a self-priming chamber (4), chamber partition plates (2) a concave-convex impeller (3), inlet channels (6) connected on two sides of the self-priming chamber (4), a spring device (7) of an upper-side x-shaped gas-liquid separation device, the upper-side x-shaped gas-liquid separation device (8), upper and middle-side gas-liquid separation device connecting shafts (9), a middle-side gas-liquid separation device (10), lower-side backflow-type gas-liquid separation devices (11), v-shaped backflow channels (122), an inverted v-shaped inlet channel (121), and an inlet. The quick no-water startup apparatus of the present invention enables the centrifugal pump to directly enter a normal operating condition after no-water startup, and 36 times of air exhaust can be completed while the concave-convex impeller (3) in the self-priming chamber (4) rotates by a circle in the early stage. Besides, the apparatus is provided with the upper, middle, and lower gas-liquid separation devices to fully realize separation of gas and liquid, so that gas can be exhausted more quickly and the chamber is filled with water. Therefore, the working efficiency is significantly improved and the operation process is greatly simplified.

A pump includes a motor housing configured to support a motor and a pump head coupled to the motor housing. The pump head includes an inlet configured to receive a fluid, an outlet in fluid communication with the inlet, and a bypass assembly configured to facilitate a path for fluid removal. The bypass assembly includes a bypass housing defining a channel in fluid communication with the inlet, a bypass vent in fluid communication with the channel, and a sealing member movably supported within the channel. The sealing member movable between a closed position where the sealing member blocks flow of the fluid from the inlet through the bypass vent and an open position where the inlet is fluidly connected to the bypass vent. An impeller positioned within the pump head and the bypass assembly is positioned downstream of the inlet and upstream of the impeller and the outlet.

A self-orienting gas evading intake for a submersible pump provides an efficient, reliable and inexpensive system for pumping a downhole fluid to a surface. An intake section of a submersible pumping system may comprise a blocker sleeve disposed between an external housing and an eccentric intake. The intake section may be self-orienting such that a gas component of the fluid ascends the borehole to separate from a liquid component of the fluid. Actuation of a blocker sleeve exposes one or more ports of the external housing while blocking one or more other ports. The liquid component is drawn into the intake section through an exposed port and through one or more openings of the eccentric intake. The liquid component may then be drawn into the pump. As the liquid component comprises non-detrimental amounts, if any, of a gas component, the pump operates efficiently and effectively.

A self-priming apparatus for quick no-water startup includes a front-stage inlet chamber, a middle-stage gas-liquid separation chamber, and a rear-stage gas-liquid separation chamber. A plurality of two-stage chamber gas-liquid separation one-way channels are symmetrically arranged between adjacent chambers of the front-stage inlet chamber, the middle-stage gas-liquid separation chamber and the rear-stage gas-liquid separation chamber. A plurality of one-way outlets are symmetrically arranged in an inner cavity of the rear-stage gas-liquid separation chamber. By decreasing or increasing the volumes of an outer cavity and an inner cavity of the front-stage inlet chamber, water is sucked in due to pressure difference and water intake and preliminary gas-liquid separation are carried out. The middle-stage gas-liquid separation chamber is configured for gas-liquid separation. By decreasing or increasing the volume of the inner cavity of the rear-stage gas-liquid separation chamber, water is rapidly expelled due to pressure difference and gas-liquid separation is carried out.