A screen intake apparatus for a water intake system uses a cleaning system to clean one or more screen intakes. To clean debris from a screen, pipes in the interior of the screen receive pumped liquid (e.g., water or incompressible liquid) from a pump. Outlets, such as apertures or nozzles, on the pipes then direct the pumped liquid into the interior of the screen. One or more valves can vary, agitate, or pulse the flow of pumped fluid and/or can selectively deliver the pumped liquid to the pipes to remove collected debris from the exterior of the screen. A heater of the system can also heat the pumped liquid for delivery to the pipes to remove or prevent ice formation on the screen.

A screen intake apparatus for a water intake system uses a cleaning system to clean one or more screen intakes. To clean debris from a screen, pipes in the interior of the screen receive pumped liquid (e.g., water or incompressible liquid) from a pump. Outlets, such as apertures or nozzles, on the pipes then direct the pumped liquid into the interior of the screen. One or more valves can vary, agitate, or pulse the flow of pumped fluid and/or can selectively deliver the pumped liquid to the pipes to remove collected debris from the exterior of the screen. A heater of the system can also heat the pumped liquid for delivery to the pipes to remove or prevent ice formation on the screen.

A pump system for a water supply mains has at least one pump device, a pressure detecting sensor at the pressure side of the pump device, a flow detecting sensor of the pump device, several pressure sensor units (D) remote arranged remotely from the pump device in different part regions of the mains, and a pump control device. The control device includes a model formation module designed in each case to produce a model (A) representing pressure loss from the pressure sensor to the position of the respective pressure sensor unit (D), based on several pressure measured values of at least two pressure sensor units (D) for the at least two associated part regions. The control device is designed for regulation of the pump device based on produced models (A), as well as to a corresponding method for regulation of a pump device in a water supply mains.

A pump system for a water supply mains has at least one pump device, a pressure detecting sensor at the pressure side of the pump device, a flow detecting sensor of the pump device, several pressure sensor units (D) remote arranged remotely from the pump device in different part regions of the mains, and a pump control device. The control device includes a model formation module designed in each case to produce a model (A) representing pressure loss from the pressure sensor to the position of the respective pressure sensor unit (D), based on several pressure measured values of at least two pressure sensor units (D) for the at least two associated part regions. The control device is designed for regulation of the pump device based on produced models (A), as well as to a corresponding method for regulation of a pump device in a water supply mains.

A pumping system and method for blending hydraulic fracturing fluids includes a liquid additive holding tank having an outlet at a bottom of the holding tank, a first sensor at a first location in the holding tank adjacent a lower portion of the holding tank, and a second sensor at a second location in the holding tank above the first location. The pumping system further includes a liquid additive pump to deliver fluid gravity fed from the outlet of the holding tank, a chemical transfer pump to pump fluid into the holding tank in response to receiving a first signal that a fluid level of the holding tank is below the first sensor and cease to pump fluid into the holding tank in response to receiving a second signal from the second sensor indicating the fluid level is above the second sensor.

A pump system for a water supply mains has at least one pump device, a pressure detecting sensor at the pressure side of the pump device, a flow detecting sensor of the pump device, several pressure sensor units (D) remote arranged remotely from the pump device in different part regions of the mains, and a pump control device. The control device includes a model formation module designed in each case to produce a model (A) representing pressure loss from the pressure sensor to the position of the respective pressure sensor unit (D), based on several pressure measured values of at least two pressure sensor units (D) for the at least two associated part regions. The control device is designed for regulation of the pump device based on produced models (A), as well as to a corresponding method for regulation of a pump device in a water supply mains.

A pump system for a water supply mains has at least one pump device, a pressure detecting sensor at the pressure side of the pump device, a flow detecting sensor of the pump device, several pressure sensor units (D) remote arranged remotely from the pump device in different part regions of the mains, and a pump control device. The control device includes a model formation module designed in each case to produce a model (A) representing pressure loss from the pressure sensor to the position of the respective pressure sensor unit (D), based on several pressure measured values of at least two pressure sensor units (D) for the at least two associated part regions. The control device is designed for regulation of the pump device based on produced models (A), as well as to a corresponding method for regulation of a pump device in a water supply mains.

A water supply system for an aircraft has water lines which lead to a consumer group with at least one water consumer and at least one buffer upstream of the at least one water consumer. A discharge line discharges water from a water tank into the water lines and a feed pump in the discharge line supplies water from the water tank into the water lines. Each of the water lines is a flexible hose made of plastic with an internal diameter of at least 4 mm and a length of at most 100 m, and the feed pump is configured to convey water from the water tank into the water lines at a pressure of at most 25 bar and a flow rate of at most 1.4 liters per minute.

A water supply system for an aircraft has water lines which lead to a consumer group with at least one water consumer and at least one buffer upstream of the at least one water consumer. A discharge line discharges water from a water tank into the water lines and a feed pump in the discharge line supplies water from the water tank into the water lines. Each of the water lines is a flexible hose made of plastic with an internal diameter of at least 4 mm and a length of at most 100 m, and the feed pump is configured to convey water from the water tank into the water lines at a pressure of at most 25 bar and a flow rate of at most 1.4 liters per minute.

A mixing valve includes a mixing chamber, a first flow control valve having a first flow control opening, and a second flow control valve having a second flow control opening. The first and second flow control openings each have a diameter of approximately six millimeters and the mixing valve has a flow coefficient of approximately 2.5 when both flow control valves are in a mid-open position.