Control

FMECHANICAL ENGINEERING LIGHTING HEATING WEAPONS BLASTING ENGINES OR PUMPS F04Liquid pumps F04DNON-POSITIVE DISPLACEMENT PUMPS

F04D15/00Control

F04D15/0005by using valves F04D15/0011by-pass valves F04D15/0016mixing-reversing- or deviation valves F04D15/0022throttling valves or valves varying the pump inlet opening or the outlet opening F04D15/0027Varying behaviour or the very pump F04D15/0033By-passing by increasing clearance between impeller and its casing F04D15/0038by varying the effective cross-sectional area of flow through the rotor F04D15/0044by introducing a gas F04D15/005the pumps being of the circumferential flow type F04D15/0055Rotors with adjustable blades F04D15/0061responsive to temperature F04D15/0066by changing the speed F04D15/0072Installation or systems with two or more pumps, wherein the flow path through the stages can be changed F04D15/0077Safety measures F04D15/0083Protection against sudden pressure change F04D15/0088Testing machines F04D15/0094Indicators of rotational movement F04D15/02Stopping of pumps, or operating valves, on occurrence of unwanted conditions F04D15/0209responsive to a condition of the working fluid F04D15/0218the condition being a liquid level or a lack of liquid supply F04D15/0227Lack of liquid level being detected using a flow transducer F04D15/0236Lack of liquid level being detected by analysing the parameters of the electric drive F04D15/0245responsive to a condition of the pump F04D15/0254the condition being speed or load F04D15/0263the condition being temperature, ingress of humidity or leakage F04D15/0272the condition being wear or a position F04D15/0281responsive to a condition not otherwise provided for F04D15/029for pumps operating in parallel