US Patent 7870877 Coated pipes for harsh environments

The present invention relates to a pipe, especially an oil pipe, having a lining comprising a fluoropolymer adhered to its interior surface and a lining formed on its exterior surface. The interior and/or exterior lining may comprise a primer layer comprising a fluoropolymer, and preferably a perfluoropolymer and an overcoat or a preformed film adhered to the primer layer. Either the overcoat or the preformed liner also comprises a fluoropolymer, and preferably a perfluoropolymer. The surface of the lining facing the flowable media, such as oil, may be a pure perfluoropolymer to provide a particularly good non-stick surface for the oil.