a coating for use in protecting surfaces susceptible to environmental degradation . the coating may be applied to metallic surfaces for providing a barrier against elements and / or ambient conditions that would otherwise degrade the surface material . the coating includes multiple layers , where a thermoplastic polymer is included , wholly or partly , within one or more of the layers . example applications of the coating are for protecting valve seat seals and valve stem seals of a valve assembly used in conjunction with handling of fluids produced from a subterranean formation .