A pumping device ( 100, 200) comprising: a rotodynamic pump with a pump housing which defines a pressure chamber that houses an impeller, a propeller or a rotor which is driven by an electric motor, and a flow control system ( 122, 220), with the flow control system ( 122, 220) comprising: a non-return valve ( 124, 230) having a closing member ( 126, 232) movable between an open position and a closed position to allow a unidirectional fluid flow, the non-return valve ( 124, 230) includes a restoring means to apply a restoring force on the closing member ( 126, 232) to maintain the closing member ( 126, 232) in closed position; and an actuation mechanism ( 128, 242) having an actuation element ( 130, 244) movable between an operative position and an inoperative position with respect to the closing member ( 126, 232), wherein in the operative position the actuation element ( 130, 244) applies a counteracting force to move the closing member ( 126, 232) towards the open position, characterized in that the actuation element ( 130, 244) is biased towards the operative position caused by a positioning means, where the counteracting force exerted by the positioning means is greater than the restoring force (R F) exerted by a valve spring forming the restoring means on the closing member ( 126, 232), where the electric motor of the rotodynamic pump is switched off as no fluid flow is detected and the hydrostatic fluid pressure in a discharge line is equal to or above a threshold start-up pressure, and where a combined force due to the restoring force and the hydrostatic fluid pressure acting on the closing member is more than the counteracting force exerted by the positioning means. a rotodynamic pump with a pump housing which defines a pressure chamber that houses an impeller, a propeller or a rotor which is driven by an electric motor, and a flow control system ( 122, 220), with the flow control system ( 122, 220) comprising: a non-return valve ( 124, 230) having a closing member ( 126, 232) movable between an open position and a closed position to allow a unidirectional fluid flow, the non-return valve ( 124, 230) includes a restoring means to apply a restoring force on the closing member ( 126, 232) to maintain the closing member ( 126, 232) in closed position; and an actuation mechanism ( 128, 242) having an actuation element ( 130, 244) movable between an operative position and an inoperative position with respect to the closing member ( 126, 232), wherein in the operative position the actuation element ( 130, 244) applies a a non-return valve ( 124, 230) having a closing member ( 126, 232) movable between an open position and a closed position to allow a unidirectional fluid flow, the non-return valve ( 124, 230) includes a restoring means to apply a restoring force on the closing member ( 126, 232) to maintain the closing member ( 126, 232) in closed position; and an actuation mechanism ( 128, 242) having an actuation element ( 130, 244) movable between an operative position and an inoperative position with respect to the closing member ( 126, 232), wherein in the operative position the actuation element ( 130, 244) applies a counteracting force to move the closing member ( 126, 232) towards the open position, characterized in that the actuation element ( 130, 244) is biased towards the operative position caused by a positioning means, where the counteracting force exerted by the positioning means is greater than the restoring force (R F) exerted by a valve spring forming the restoring means on the closing member ( 126, 232), where the electric motor of the rotodynamic pump is switched off as no fluid flow is detected and the hydrostatic fluid pressure in a discharge line is equal to or above a threshold start-up pressure, and where a combined force due to the restoring force and the hydrostatic fluid pressure acting on the closing member is more than the counteracting force exerted by the positioning means.