A method for controlling an inlet-adjustment mechanism in an air inlet for a compressor so as to switch the mechanism in a binary fashion between open and closed positions for adjusting a flow area of the inlet. The method includes identifying a threshold line on a compressor map of pressure ratio versus corrected flow rate for the compressor, at which the inlet-adjustment mechanism is switched from one of its positions to the other. A fixed switch band straddling the threshold line can be used for determining when to initiate the switch of positions so as to time the switch to coincide with the operating point reaching the threshold line. Alternatively, a time to reach the threshold line can be instantaneously computed and compared to the actuator/mechanism response time.

A pump station arrangement and a method for turning off a pump configured for pumping liquid via a conduit. The pump, before being turned off, being driven at an operational frequency (F.sub.N) by a control unit. The method is characterized by the steps of, ramping down the frequency of the pump due to a turn off instruction, the terminal frequency of the ramping down being equal to the operational frequency (F.sub.N) of the pump minus at least 10 Hz and the ramping down time being at least a reflection time (T.sub.R) for the conduit in question, and the terminal frequency of the ramping down not being less than 10 Hz, and stopping the pump after the ramping down.

A system includes a first pump connected to an inlet line and connected to a first outlet line for supplying a first sub-system over a first pressure schedule. A second pump is connected to the inlet line and connected to a second outlet line for supplying a second subsystem over a second pressure schedule. A backup selector is in fluid communication with the first and second outlet lines. The backup selector is configured to switch to a first backup mode to supply the first sub-system from the second pump upon failure of the first pump. The backup selector is configured to switch to a second backup mode to supply the second sup-system from the first pump upon failure of the second pump.

The multi-stage submersible pump at the exit side is provided with a non-return valve (9) including a valve seat (19) and a shut-off body (15) which is movably arranged thereto in a limited manner and which is arranged with a positive fit and in a movable manner within a guide (16) surrounding the shut-off body (15) with play. The inner contour of the guide (16) tapers inwards towards the valve seat (19), counter to the main flow direction (13).

A dual pump unit having a pair of pumps that provide parallel hydraulic paths, and are configured to operate concurrently in opposite rotational directions. The dual pump unit has a sealed casing which includes a suction flange, two volutes in hydraulically parallel configuration, and a discharge flange. The pair of pumps are located within a respective volute of the casing and, in an example, are radially inline and horizontally inline. The casing may include a flattened bottom. Each pump may include a touchscreen for configuration of the respective pump. The pumps are controllable to circulate a circulating medium to collectively provide output to source a load.

A slurry injection system and method for operating the same has a plurality of clear fluid pumps receiving clear fluid from a low pressure clear fluid manifold, pressurizing the clear fluid into high pressure clear fluid and communicating the high pressure clear fluid into the high pressure clear fluid manifold. A blender unit has low pressure slurry therein. A mixer receives clear fluid. A slurry pressurizer is in fluid communication with the high pressure clear fluid manifold through a bypass pump. The slurry pressurizer forms high pressure slurry by pressurizing the low pressure slurry from the blender unit using high pressure manifold clear fluid that is communicated to the mixer and communicates low pressure fluid to the low pressure clear fluid manifold. The mixer mixes the high pressure slurry and clear fluid to form a mixture that is communicated to a slurry injection site.

A pump device is proposed for arrangement on a recirculation line of an industrial water system including a feed pump, a check valve and a bypass line for the check valve. The bypass line is arranged in parallel to the check valve and wherein a combination of the check valve and bypass line is arrange in series to the feed pump.

A gas seal column apparatus includes a vertically-oriented column, a pump, an inlet pipe, a an outlet pipe, and a drive shaft driven by any type of motor. The pump and the gas seal column comprise a vertically-oriented pump system. The inlet pipe receives pressurized seal gas for introducing the seal gas into the pump system. The outlet pipe enables the seal gas to exit the pump system. The drive shaft is encased by the gas seal column between the pump drive motor and the pump to couple the pump drive motor to the pump.

A slurry injection system and method for operating the same has a plurality of clear fluid pumps receiving clear fluid from a low pressure clear fluid manifold, pressurizing the clear fluid into high pressure clear fluid and communicating the high pressure clear fluid into the high pressure clear fluid manifold. A blender unit has low pressure slurry therein. A mixer receives clear fluid. A slurry pressurizer is in fluid communication with the high pressure clear fluid manifold through a bypass pump. The slurry pressurizer forms high pressure slurry by pressurizing the low pressure slurry from the blender unit using high pressure manifold clear fluid that is communicated to the mixer and communicates low pressure fluid to the low pressure clear fluid manifold. The mixer mixes the high pressure slurry and clear fluid to form a mixture that is communicated to a slurry injection site.

A gas seal column apparatus includes a vertically-oriented column, a pump, an inlet pipe, a an outlet pipe, and a drive shaft driven by any type of motor. The pump and the gas seal column comprise a vertically-oriented pump system. The inlet pipe receives pressurized seal gas for introducing the seal gas into the pump system. The outlet pipe enables the seal gas to exit the pump system. The drive shaft is encased by the gas seal column between the pump drive motor and the pump to couple the pump drive motor to the pump.