Compressed air will flow through the ejector and create a vacuum in the pump casing and suction line. After priming, the pumps will build up pressure in the discharge line which will activate the presure switch. The presssure switch then disconnect the power to the solenoid valves and the priming stops automatically.
At a fluid pressure of e.g. 10 m / 33 ft total head the unit will disconnect automatically (adjustable from 3 – 100 m / 10 ft – 328 ft total head). If the pressure drops to less than 10 m / 33 ft total head, the unit will automatically start functioning until a counter pressure has been reestablished.