Bolt Corrosion Prevented by Corrosion-Inhibiting Spray-On Thermoplastic

Numerous industrial facilities, especially offshore oil and gas installations, are plagued by bolt corrosion problems. With a limited record of success in prevention or cure, material loss from corrosion is often factored into maintenance planning, with bolt replacement as a solution when integrity is threatened.

An increasing focus on overall maintenance as an essential part of reducing problems in safety-critical systems makes the prevention of corrosion effects on basic components such as bolts and fasteners an increasingly important goal. This paper describes a corrosion-inhibiting thermoplastic system that has demonstrated success in the provision of extended corrosion protection on both new and rusting bolts in extreme conditions.

The system uses special equipment to spray a thermoplastic material containing built-in inhibiting oils to encapsulate the substrate. The paper includes a review of current bolt coating systems and materials and the concept and function of the thermoplastic system, together with field case histories over a number of years where this product has effectively prevented or stopped on-going bolt corrosion issues found in offshore oil and gas production systems as well as the in mining industry and on LPG tankers.