in china, the urban and rural areas, the catering industry and the vast towns and villages that have not been widely used in natural gas have also used a large amount of bottled gas. from the recent analysis of gas safety accidents, a large part of gas safety accidents are caused by bottled gas. the gas cylinder is used for special equipment for liquefied gas. the circulation is made up of professional gas cylinder filling units and gas-operated enterprises. the main body of gas cylinder safety is also the gas station. as a regular gas station, they purchase new bottles, sell liquefied gas, ship them to users, recycle empty bottles, and continue to sell them to users after refueling. in this cycle, cylinders can be reused, and new bottles will be replaced with old ones. the condition of the bottle.