Two-layer with copper welded steel, which on the outside with zinc and pvf, the inside is coated with nickel

摘要

The present invention relates to two-layer tubes (1) with a high corrosion resistance and - resistance, which is made of sheet metal with copper welded steel tubes (2), which, by means of forming a zinc layer (3) on the outer surface and a nickel layer (5) on the inner surface of the with copper welded steel sheet metal tubes (3) are obtained, and which include a manufacturing method thereof. The method comprises the steps of the cleaning of the sheet metal with copper welded steel tubes (2) with zinc and pvf (polyvinyl fluoride), which are applied to the outer surface, in a cleaning section (7) of an electroless nickel plating road (6); the washing in a wash bath (8); of subjecting of an activation process in an activation section (9); of the coating process, the inner surface with a nickel plating solution in a currentless nickel plating (10); the renewed washing; of the drying in a drying section (11); of applying a leak tests; of the packaging and the vert rubbing.