Summary
The Sister CO2 high-pressure filling system is a new gas filling method developed by the company through comprehensive investigation and combined with the current situation of various gas companies, focusing on the design concept of "safety, efficiency, and intelligence" from various perspectives. This filling method is widely used in semi-automatic filling systems and fully automatic filling systems.
Due to the fact that carbon dioxide cylinders are high-pressure vessels with a critical temperature of 31.1 ℃, gases cannot liquefy above this critical temperature. If the temperature of a liquid carbon dioxide cylinder is higher than 31.1 ℃, regardless of the pressure, the carbon dioxide will always remain in a gaseous state and cannot liquefy. The pressure of the cylinder will increase sharply, which may lead to the risk of explosion. Therefore, when storing and using carbon dioxide in steel cylinders, it is necessary to use 150kg/cm2 or 200kg/cm2 grade steel cylinders, and they must be strictly inspected and qualified before application. The relevant regulations in the "Gas Cylinder Safety Supervision Regulations" of the former State Administration of Labor must be strictly followed. During storage and transportation, exposure to sunlight must be strictly prevented, and knocking, collision, baking, and proximity to heat sources are strictly prohibited. When carbon dioxide is depressurized through a gas cylinder, it absorbs a large amount of heat, causing the cylinder to frost and even potentially freezing the valve core. When the carbon dioxide valve is frozen, it should not be knocked or baked with fire, only washed with tap water for heating.

The nominal working pressure of carbon dioxide gas cylinders is 15MPa, and the pressure at the end of filling is 7-8MPa. Overfilling is strictly prohibited and must be filled according to the standard of 0.6kg/L.

Full liquid temperature at different filling coefficients: