A system and method for operating centrifugal pumps related to net positive suction head (NPSH), including identifying a group of centrifugal pumps and deriving an equation for the group based on manufacturer data of the centrifugal pumps collectively in the group, the equation correlating NPSH required (NPSHr) with flowrate of pumped fluid, wherein the manufacturer data includes NPSHr for each centrifugal pump of the group as a function of the flowrate of the pumped fluid. The technique includes specifying a NPSH margin for NPSH available (NPSHa) above the NPSHr.

The present discloses a pump apparatus having a first pump and at least one controller. The at least one controller is suitable for generating a first control signal for controlling the first pump. The at least one controller is suitable for generating a second control signal for controlling operation of a second pump. The second pump is external to the pump apparatus. One or more pump connection port is provided in the pump apparatus for outputting the second control signal to the second pump. The present disclosure also relates to a vacuum system comprising a pump apparatus of the type described herein.

A multi-switch pump assembly is disclosed that facilitates switched flow and/or mixed flow from the pump assembly. The multi-switch pump assembly comprises a pump body, an electric motor, a rotating motor shaft, a first pump stage and impeller, and a second pump stage and impeller. The first pump stage includes a first inlet and first and second outlets disposed about the pump body. The second pump stage includes a second fluid inlet connected to a mix chamber. The mix chamber further connected to the second fluid outlet of the first pump stage. The second stage further includes a second and a third outlet disposed about the pump body. An actuator connected to a valve assembly is arranged to operate and place the valve assembly into at least a first, a second, a third and a fourth switched positions to direct fluid flow between the first and the second pump stages and the first, second, third and fourth fluid outlets.

The present application relates to a pump unit for a fuel injection system. The pump unit has a low pressure fuel supply line and a high pressure fuel outlet. A pumping chamber having a plunger is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit also includes an inlet valve having an inlet valve member movable between an open position for permitting the supply of fuel to the pumping chamber from the low pressure fuel supply line and a closed position for inhibiting the supply of fuel from the pumping chamber to the low pressure supply line. An outlet valve is provided in the high pressure fuel outlet. The pump unit also includes a means for latching the inlet valve member in its open position. The present application also relates to a method of operating a pump unit.

A method of maintaining a gas turbine engine whilst the gas turbine engine is shut down, the gas turbine engine comprising a core and the method comprising: providing an axial airflow through a core of the gas turbine engine, during a time period after shut-down and before start-up of the gas turbine engine.

The disclosure relates to a drive protection and management method of a pressurization system comprising at least two operatively independent hydraulic pumps, the method including setting a plurality of predetermined parameters by a user by means of an electronic control unit at each of the hydraulic pumps, detecting at least one pressure value by means of at least one pressure sensor at a delivery duct of each of the hydraulic pumps, determining a drive in a sequential and/or synchronized manner of the at least two hydraulic pumps by managing and interpolating, independently for each pump, these predetermined parameters and the at least one pressure value at each of the hydraulic pumps by means of each electronic control unit. The disclosure relates to a pressurization system as well, adapted to implement this method.

A control unit includes a casing, a first exhaust fan disposed close to a first side surface of the casing to exhaust air inside the casing, a first air intake port disposed to correspond to the first exhaust fan and formed in a second side surface opposite to the first side surface, a second exhaust fan disposed adjacent to the first exhaust fan and close to the first side surface to exhaust air inside the casing, a second air intake port disposed to correspond to the second exhaust fan and formed in the second side surface, a first cooling target object disposed to correspond to the first exhaust fan, a second cooling target object disposed to correspond to the second exhaust fan, and a CPU for controlling a revolution speed of the first exhaust fan and a revolution speed of the second exhaust fan.

The invention, comprises a pumping apparatus, system and method for increasing the flow of the in a first direction to boost liquid flow and in a reverse second direction to remove blockages and/or self-clearing, with operation having an rotor/impeller that can use a shredder and/or shearing action utilizing blades for processing to pass solids, debris and other things to prevent clogging and/or self-cleaning of the unit.

The invention comprises a pumping apparatus, system and method for increasing the flow of the in a first direction to boost liquid flow and in a reverse second direction to remove blockages and/or self-clearing, with operation having an rotor/impeller that can use a shredder and/or shearing action utilizing blades for processing to pass solids, debris and other things to prevent clogging and/or self-cleaning of the unit.

A pump for fluids includes a pump housing, a power source enclosed within the housing, a drive shaft connected to the power source, at least one pump inlet arranged in the pump housing, a pump outlet arranged in the pump housing, a first impeller arranged within a first impeller chamber and rotated by the drive shaft, and a second impeller arranged within a second impeller chamber and rotated by the drive shaft. The pump is changeable between a first configuration in which the first and second impeller are arranged in parallel to provide a high pumping capacity, and a second configuration in which the first and second impeller are arranged in series to provide a pump with less pumping capacity.