When the water level drops, the main valve is composed of a floating ball switch control to open the water inlet to the water tank, automatic replenishment.
当水位下降后，主阀由浮球开关控制打开进水口向水池汪水，实现自动补水。
2
Implements by the relay to the electric motor, the inletvalve, draw-off valve's control.
由继电器实施对电动机、进水阀、排水阀的控制。
3
This paper derives the characteristic formula of control pressure in hydro-control check valve and the mechanical characteristics formula of inlet and return circuit.