Corrosion-proof composite tube for use in contact with flue gas etc.

摘要

A corrosion-resistant composite tube (I) comprises a steel tube coated with: (a) a first layer of enamel (II), and then with (b) an outer coating of plastic (III), matched so that diffusion prods. which pass through (III) have no corrosive effect on (II), and acids which attack (II) cannot diffuse through (III). Also claimed is a process for the prodn. of tube (I) by coating a steel tube first with (II) and then with (III).