Heat exchangers are a critical industrial component used to keep chemicals, water, gas, and other substances within a safe operating temperature. Damage to any of its components can pose significant risks to the facilities and workers that operate them. Read on to learn how Advanced FRP Systems helped a chemical manufacturer salvage one of their critical heat exchangers. Through-Wall Failures Identified During an inspection, the chemical manufacturing facility found through-wall failures in the 90-inch diameter exterior shell of a heat exchanger that handled acetic acid. Operating at temperatures in excess 195°F, the heat exchanger was critical to the daily operations of the facility and could not be taken offline. After considering a metallic clamp and deciding that it would not be a cost-effective solution due to the size of the shell, the facility reached out to Advanced FRP Systems to inquire about a potential solution. How Do Heat Exchangers Work? The material flows through the smaller pipes inside of the exchanger as another substance, typically water, flows through the larger portion to change the temperature. Row of Heat Exchangers Internal Schematic of Heat Exchanger Internal Tubing with Shell Removed Advanced FRP’s High-Temperature Composite Solution Advanced FRP Systems had previously designed high-temperature composite systems suitable for services up to 375℉ once cured. Still, the elevated operating temperatures during the planned application posed a unique challenge and had not been previously tested. Typically, application at elevated temperatures can cause the epoxy resin used in the composite to quickly thin, causing runs and sags that could affect the successful installation and performance of the system. As mentioned in one of our previous blog posts, it is imperative that any composite system planned for use in high-temperature environments be thoroughly tested. Once our team was contacted, we worked with the facility to identify the specific service temperatures and planned application temperatures. From there, our experts designed an epoxy resin system with increased levels of thixotropes. This “thickened” the resin, allowing it to withstand application at elevated temperatures. Once this new composite system was tested and thoroughly vetted by Advanced FRP Systems, installation began. The Application and the Result As a first step, Advanced FRP’s team blasted the shell to an SSPC SP-10 Near White Metal finish via grit blasting. The through-wall failures in the shell were temporarily plugged and all weld seams and heavily pitted areas were smoothed over with our FRP Repair Putty HT, a high-build epoxy putty specifically designed for use in high-temp applications. After the surface preparation, our specially formulated FRP 211 HT Saturant was then used to prime the tank surface and to saturate our bi-directional, aerospace-grade, high-strength carbon fiber fabric, CF-500 BD. Three layers of saturated carbon fiber fabric were wrapped around the exterior of the tank. Advanced FRP HP 400 Novo epoxy coating system was then rolled onto the composite to provide a topcoat and complete the composite repair system. The elevated temperatures did cause the epoxy resins to cure very quickly, sometimes in a matter of minutes. While this is typically an issue with coatings as bubbling or delamination can occur when an epoxy cures too quickly, our rigorous testing in the lab showed that this would not occur with our products, and they would be successfully applied. The installation was completed without delay, and the facility was able to continue operations. Project Completed on Target In the four years since the installation, the facility did not report any additional leaks on the heat exchanger shell. However, due to the leaking of the internal tubes, the facility replaced the entire heat exchanger. After taking it apart, the client was astonished to see that the carbon fiber composite system had held up despite the continued internal corrosion that turned the penny-sized holes into basketball-sized through-wall failures. Need Help with High-Temperature Composite Reinforcement? Contact Us. At Advanced FRP Systems, we value the trust our customers put in us to take the time to dive into their unique problems, build the right custom solution and deliver on quality products and guidance. If you are interested in working with Advanced FRP Systems to find a repair solution that fits your needs, or if you’d like more information about our services and products, call us at 508-927-6915, or email us at firstname.lastname@example.org.