This study presents a state-of-the-art review on maintenance practices and coating systems for protecting the above-ground portion of steel transmission tower structures from corrosion. Information was obtained from a variety of sources: (1) a survey of major international electric utilities, (2) technical data and product recommendations provided by coating suppliers, (3) recent standards issued by NACE, IEEE, and ISO, and (4) published electric utility case studies. The best practices for steel transmission tower inspection and maintenance programs are reviewed. The report identifies the optimum time to apply corrosion protection coatings to individual transmission towers as well as to an entire fleet. Surface preparation and coating application methods for steel transmission towers are identified. Coating durability is discussed and specific recommendations are given for protective coating systems based on substrate type (e.g., bare steel, weathered galvanizing, aged paint coatings) and the in-service environmental exposure conditions (e.g., rural, industrial,marine, chemical). The costs of tower coating programs are also reviewed. Surface preparation requirements and application instructions are provided for the top ranked coating systems.
Steel Transmission Tower, Above Ground Coating Maintenance, Industry Survey, Corrosion Protection, Protective Coating, Aged Galvanizing, Rust, Surface Preparation, Durability, Epoxy,Vinyl, Long Oil Alkyd, Inorganic Zinc-rich, Urethane