PURPOSE: To automate pump starting operations by allowing detection signals transmitted from a priming detector in a pump casing and from a pressure switch in a discharge line to open or close a motor-driven discharge valve installed in an operating preparation pump discharge line and then to provide energized timing for pomp starting.

CONSTITUTION: A water feed pump P1 is going to be started, when two coupled feed pumps P2 and P3 are running. Motor-driven discharge valves 4' and 4" installed to the running pumps P2 and P3 have been already opened. Before starting the operating preparation pump P1, the motor-driven discharge valve 4' is opened so that the water delivered from a running pump either P2 or P3 is introduced into the pump casing through a discharge nozzle 6 of the operating preparation pump P1 and fills the casing while exhausting air through an air vent valve 2. Priming signals from a detector 3 closes the motor-driven discharge valve 4 and then automatically starts the operating preparation pump P1 and hence makes remote control possible.