Suitable for highly corrosive gases and liquids at high temperatures; other types of steel-plastic composite pipes and metal pipes are not suitable for conveying medium. Both steel-polyester composite pipes and steel-polyvinylidene fluoride (PVDF) composite pipes are applicable. The conveying working temperature for steel-polyvinylidene fluoride (PVDF) composite pipes is suitable for corrosive media at -40℃ to +150℃.