CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.
Issue link: http://coatingspromag.epubxp.com/i/72303
SPECIFYING SUCCESS Specifying Vinyl Ester Linings for FGD Applications By Jeffrey Stewart, P.E. the process of power production. Utility management requires the minimizing of the negative impact on the business. Resin-lined carbon steel is the material of choice to maximize life cycle cost and schedule length. One significant problem with this option: There seems to be little faith throughout the industry in the long-term performance of vinyl ester f lake glass linings. Because of the highly corrosive T environments in FGD installations, it is necessary to protect the steel from corrosion or find alternative construc- tion materials. Most early FGD systems instal led in the United States were designed and built using carbon steel with a resin lining system, usually a polyester-based flake glass. The perfor- mance of he addition of a Flue Gas De sulfurizat ion (FGD) system to a power plant adds cost and complicat ion to Photos courtesy of ITW PolySpec-Futura these systems was a spotty mixture of successes and spectacular failures. The failures gave rise to a vigor- ous search for alternate materials. Exotic metal alloys, solid fiberglass reinforced plastic (FRP), and acid-resistant ceramic tiles have all enjoyed relative successes and pushed the resin linings option out of the spotlight in the United States. However, they remained a primary material of choice overseas. The reason that other countries, most notably Japan, continued to specify and use resin linings is because of their long-term success (in contrast to the spotty perfor- mance in the United States) and because of the economic advantages of the resin lining technology over other more costly technologies. Units in Japan commonly achieve 20 or more years of service with little to no material replacement. 24 CoatingsPro J July 2012 Because of the highly corrosive environments in FGD installations, it is necessary to protect the steel from corrosion or find alternative construction materials. While the same material building blocks and technology are available in the United States, there exists a large perfor- mance gap that requires explanation. Areas of significant differences are: speci- fications with initial systems designs that feature, on average, higher film builds, an emphasis on designing the lining system on a zone-by-zone basis, the emphasis placed on the quality of application, and well-monitored and executed inspection and maintenance programs throughout the life of the lining system. Two of the three noted issues are what make up a Lining Application Specification. The importance of an accurate speci- fication is highly emphasized in the data compiled in a study by Mark Westin (ref 1) and shown in the table, "Believed Causes of Lining Failures." The key components of a well- written specification are: t Identification of the lining materials and their location (commonly referred