Municipal infrastructure dedicated to the catering industry. Restaurant smoke exhaust pipeline is a kind of municipal infrastructure dedicated to catering industry, which is used to circulate air and reduce the concentration of lampblack gas. With the acceleration of urbanization in China, the proportion of gas used in urban gas pipelines is increasing. Stainless steel gas bellows has strong corrosion resistance, high hardness, long service life, and more importantly, it is resistant to high and low temperatures, so it is widely used in catering industry.