Materials Performance Supplements

Corrosion Prevention and Control for Tanks 2017

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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14 MAY 2017 MATERIALS PERFORMANCE TANK CORROSION CONTROL SUPPLEMENT TO MP Thorpe Plant Services FRP Large Diameter/Ring Oblated Tanks vs. API 650 Steel Tanks In Industrial sectors such as petrochemical, power, pulp and paper, mining, plating, etc., there are many large diameter chemi- cal storage tanks that are in service and exposed to an array of cor- rosive chemistries such as acids, caustics, brine (salt water), waste water, etc. When looking at material options, many engineers con- sider carbon steel with a liner, stainless steel or high end alloys due to operational and/or educational familiarity when designing per API 650 specifications. At Thorpe Plant Services, we believe we have a far superior and more economical material option when selecting a tank that has a minimum 30-40 year plus life cycle. Utilizing our STRAND® Fiber- glass Reinforced Plastic (FRP) Ring Oblated designs per ASTM- 3299 specifications, Thorpe manufactures major tank components in our controlled shop environment under a strict quality control program. The shell components are shop oblated and then shipped to the site using conventional trucking methods. This reduces the number of special permitted, oversized, heavy weight and escorted loads, substantially reducing freight costs for most projects. FRP Ring Oblation is not new to the industry and was estab- lished and patented by Thorpe's Tank division in 1978. There are several hundred of these tanks in service that are meeting and exceeding design requirements. FRP Oblated Tank designs are nor- mally utilized for vessels larger than 16-ft diameter. Vessel designs utilize Premium Vinyl Ester resins for both the corrosion liner and structural wall. The resin selection is determined in conjunction with the resin manufacturers and the customer based upon the chemical environment and operational temperature. Thorpe has partnered with some of the most respected and experienced resin and glass manufacturers in North America. There are many additional benefits to a FRP Ring Oblated design. FRP designs have less welds to be performed (no vertical welds) in the field and normally are constructed from the top down. This requires less elevated work (manlifts/scaffolding ) thereby increasing productivity while minimizing safety and cost issues inherent with elevated work. The overall assembly schedule is also reduced while utilizing a smaller construction crew. Crane size and duration is also often reduced due to the reduction in weight vs. steel. FRP Ring Oblated tank design also offers long term perfor- mance savings vs. carbon steel on the maintenance side. No initial painting or ongoing maintenance painting program will be required due to the use of a premium Resin Gel Coat during manu- facturing and assembly. This acts as a "UV " inhibitor for the FRP tank. The "tank" is designed for the intended chemistry stream exposure. No special additional liner will be required as would with 6833 Kirbyville Houston, TX 77033 Tel: +1 713-644-1247 Email: Web site: a carbon steel vessel. With FRP, both the corrosion liner and the structure are the same material type and provide both internal and external corrosion resistance. Using FRP also offers high strength- to-weight ratio while having very good insulation and static-free characteristics. There are many engineering, performance, construction and long-term maintenance benefits with FRP Ring Oblated Tanks. However, the greatest benefit is the "Total Life Cycle" cost savings. There have been several case studies showing a greater than 30% savings in overall life cycle cost from initial construction to end of life cycle. Three Keys to Reliability We believe the best way to assure a successful project with long term reliability is to control all three keys to reliability : 1. Technical and Engineering Capabilities 2. Manufacturing Quality 3. Field Erection/Installation Capability Thorpe provides true turnkey project responsibility from design thru erection assuring a successful and cost-effective project. Winning Together The Thorpe Plant Services team remains committed to helping your company find the right solution, while providing you with the safest, most cost-effective and maintenance free equipment possible.

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