Development of Test Methods for Coatings Systems exposed to Extreme Hydraulic Environments
While many test methods exist for coatings, results are often unreliable when coatings are exposed to real world environments. Recent experience has shown that some coating systems peel off in penstocks and outlet pipes where high velocity flows exist or cannot endure extreme hydraulic conditions such as high shear stress, pressure fluctuations or cavitation that are present in many of our systems. The US Navy has similar coating system failures under high shear stress environments including SHT tiles on VA Class submarines, antifouling paint systems on DDG Class rudders, topside coating systems on a ship's bow, and flight deck nonskid coatings. The development of new test methods that expose coatings to real life hydrodynamic conditions is needed to improve reliability of test results.
Need and Benefit
Coatings issues were identified as the top two priorities in a recent Research Roadmap for mechanical components of Hydropower Plants (still in draft form), with penstock coatings ranking #1. Flatiron Powerplant penstocks and Enders Dam outlet pipe have had recent issues with coating adhesion and durability. In addition, we were contacted by NRL in early 2017 to help address their needs in improving test methods that simulate real life operating conditions for coatings within the Navy. Extending the service life of coatings in penstocks and outlet pipes is an urgent Reclamation need since many coal tar enamel linings are approaching the end of their service life. Improving test methods that provide more robust, real life results of coating performance will greatly benefit every region in Reclamation as well as other government agencies.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Development of Test Methods for Coatings Systems exposed to Extreme Hydraulic Environments (final, PDF,
By Josh Mortensen
Research Product completed on September 30, 2018