It is filled at a pressure higher than atmospheric pressure, which can also be divided into two types: 

One is that the pressure in the storage tank is equal to the pressure in the bottle, and it is filled by the weight of the liquid flowing into the bottle, known as isobaric filling;

Another method is that the pressure inside the storage tank is higher than the pressure in the bottle, and the liquid flows into the bottle through the pressure difference. This method is commonly used in high-speed production lines. The pressure filling machine is suitable for filling liquids containing gases, such as beer, soda, champagne, etc.