Field Experience with Interior Pipe Coatings from High Performance Polyurethane Elastomers
Proceedings Publication Date
Nonmetallic interior pipe coatings for erosion and corrosion protection are still somewhat of a specialty. Obviously, plastic coatings and liners will not suffer from corrosion as specialty steels may do. They are much less expensive. Commonplace plastic interior linings are HDPE liners, providing corrosion protection, but no abrasion resistance. Liner collapse in some cases is an issue. High performance polyurethane elastomer coatings with extremely strong steel adhesion have been developed by ROPLAST. These materials are ideally suited for highly abrasive product streams like slurries, tailings, sand containing media. Test data and field experience in applications like oil sands tailings, oil sands hydrotransport, water injection multiphase mixtures, and phosphate mining slurries, will be presented. In these applications, pipes coated with this material last > 5 times longer than uncoated steel. An unusually high barrier function against water and gases like H2S and CO2 was found. This translates into a combination of strong erosion protection and excellent corrosion protection. In salt brines, even corrosion propagation underneath the coating (around an artificial defect) was prevented by these coatings. These coatings provide excellent protection against erosion-corrosion, but could also open new opportunities for steel pipe corrosion management. An international industry project lead by a large Norwegian research institute is currently investigating long-term lifetime prediction. A simple new weld joining process has been developed and applied in Canadian oil sands hydrotransport. Only one weld per pipe joint is required in the field and there is no need for re-coating of the field joints. This presentation will give an overview over the erosion and corrosion protective properties of RoCoat™ interior pipe coatings. Performance and cost will be compared to HDPE liner and to other pipe protection methods. In Lingen, Germany, a modern coating plant for this process is providing coated pipes to customers around the world.