Bellows mainly include metal bellows, corrugated expansion joints, corrugated heat exchange tubes, diaphragm diaphragm boxes and metal hoses. Metal bellows are mainly used to compensate pipeline thermal deformation, shock absorption, absorb pipeline settlement deformation, etc., and are widely used in petrochemical, instrumentation, aerospace, chemical, electric power, water conservancy, metallurgy and other industries. Bellows made of plastic and other materials play an irreplaceable role in the fields of medium transportation, power threading, machine tools, and home appliances.