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.