Gas tank filling: Inflation is generally done from top to bottom, from high pressure to low pressure. It is recommended to chill the inflated tank in the refrigerator for 30 minutes before inflation. Warning: Operation must be performed by qualified personnel only and in accordance with applicable national safety standards. It is strictly forbidden to inflate MAPP gas or liquefied petroleum gas into flat gas tanks or cassette gas tanks. Inflation must be conducted outdoors. During the inflation process, non-gaseous components in the tank may accumulate at the upper part of the gas tank and can be discharged through the pressure release button (for approximately 2 seconds before inflation). Note: When releasing pressure, the air valve must be closed, and the device must be installed in the correct direction. The gas from multiple flat gas tanks can be collected into one gas tank through this valve for reuse. This valve is compatible with cassette converters and other standard converters, allowing gas transfer between tanks regardless of orientation and enabling flexible connections. The switch core is made of 58 copper for durability. The gas seal uses fluoroplastic O-rings, resistant to wear, chemicals, and extreme temperatures, ensuring reliable performance within a temperature range of -20°C to 250°C. Double O-ring design provides dual sealing: one for air sealing and one to prevent leakage. Gas cylinders may vary in type, but different gases must not be mixed. Always use the same type of gas. Residual gas collection bottles cannot be filled to 100% capacity, and newly purchased gas bottles should not be completely full. Two recommended methods: The first method: A simple and practical — place both the source tank and receiving tank in the refrigerator for 20 minutes without releasing pressure, then connect them immediately.