It adopts counter pressure filling principle. The filling valve adopts high precision mechanical valve. It has advantage of fast filling speed, high precision in liquid level and it only starts filling when there is a can, otherwise it will not fill.Using the device structure of fillng valve precover device and supportuing bottom device, it can guarantee the maximum stability of cans when they passing in and out of the filling machine. Filling cylinder braces use worm-gear box going up and down to satisfy cans of different height. Float switches in the filing cylinder ensure a smooth liquid inlet.