| abstract |
(57) [Summary] The corrosion-resistant multilayer tube (10) comprises a metal tube (12), a zinc layer (14) bonded to the metal tube outer surface (13), a surface treatment layer bonded to the zinc layer (14), It comprises a primer layer (17), a first polymer layer (18) bonded to the primer layer, and a second polymer layer (22) bonded to the first polymer layer (18). The method of manufacturing the tube is melt processable into a pre-treated metal tube having an outer surface having at least one zinc-based coating, a sealant coating on the zinc-based coating, and a primer coating in the form of a sealant coating. Extruding a multilayer of a suitable thermoplastic. The primer coating (17) is preferably applied by an airless spray system in a closed atmosphere, where the volatile organic compounds do not substantially escape to the atmosphere. The polymer layer remains attached to the metal tubing, even when exposed to severe corrosive environments for extended periods of time. |