If liquefied gas is to be withdrawn, the bottom of the cylinder must be elevated above the valve to allow the liquid phase to be in contact with the valve inlet. Special inversion racks are usually used to provide a safe method for cylinder inversion.

• 如果要提取液化气体，必须把钢瓶底部提高到阀门以上，使液相同阀门入口相接触。通常使用专门的倒置架来安全地倒置钢瓶。