Process for producing composite zinc-coated steel pipe with inner stainless steel lining

[0013] (Unit: mm)

[0014] Select galvanized steel pipes and stainless steel pipes, and firstly polish the inner wall of the galvanized steel pipes, flatten them, and trim them until the inner surface is smooth and free of impurities. The outer surface of the stainless steel pipe is uniformly coated with adhesive, which is a special amide hot-melt adhesive, and then is sleeved into the galvanized steel pipe, crimped and closed at both ends. The stainless steel pipe is heated and pressurized by steam, and the galvanized steel pipe is heated by electric heating. The heating temperature inside and outside is 100-110℃, and the pressure inside the stainless steel pipe is 1.6-2.0MPa. Keep it for a certain period of time until the outer and inner walls of the galvanized steel pipe and the outer wall of the stainless steel pipe are firmly compounded by the adhesive and then cooled, relieved, and finished.