Based on the experiment, a mathematical model between the quantity of air drawing and the diameter of auxiliary pipe for the tapered t branch has been established.

For an acute outgassing course in a short time, a fitting curve is obtained according to the pumping data after outgassing, so the outgassing amount is obtained from the curve.

The air-jet exhauster is a compressed air-operated device for pump priming, provided that the pump has no foot valve. Water is induced into the pump by vacuum created by the exhauster.