Sherwin-Williams Energy Barrier Coating Eliminates Corrosion Under Insulation

With optimal heat retention, Sherwin-Williams’ Heat-Flex helps heater treaters (shown), pressure vessels, storage tanks and piping maintain operating temperatures up to 350°F (177°C), with excursions to 400°F (204°C). Source | Sherwin-Williams

Sherwin-Williams’s (Cleveland, Ohio) Heat-Flex advanced energy barrier (AEB) tackles corrosion under insulation (CUI), effectively eliminating the costly and dangerous phenomenon of steel assets corroding underneath
insulation systems. The coating replaces the bulky mineral-based insulation that’s traditionally used on storage tanks, process vessels and piping to retain process heat. By eliminating the threat of corrosion, the coating offers a solution that Sherwin-Williams says is less resource-intensive than traditional insulating production systems.

Heat-Flex AEB works by building a thick film of insulative coating material onto assets that are required to maintain operating temperatures up to 350°F (177°C), with excursions to 400°F (204°C). This coating retains process heat inside coated assets, enabling continued operating even in extreme environments. Sherwin-Williams points to traditional insulation systems, which tend to absorb and trap moisture that infiltrates their exterior cladding, thus reducing the insulating capacity of the insulation and contributing to an accelerated CUI.

“Careful manipulation of the coating molecule and product formulation enabled the capability that retains process heat at temperatures high enough to remove traditional insulation and not affect the consistency and flow of
materials housed inside assets,” says Erik Dammen-Brower, R&D chemist II for Sherwin-Williams Protective & Marine. “This has notable ramifications for reducing costs and improving carbon footprint, while enabling efficiencies in various facility applications.”

Beyond the comparable heat retention capabilities, Heat-Flex AEB offers a variety of enhanced sustainability benefits. Using just the insulative
coating eliminates the manufacturing, shipping and storage of all the materials required for a traditional system — including the mineral wool insulation, wiring, pins and banding that keeps insulation in place, and
the metal cladding mounted over top. In addition, because Heat-Flex AEB eliminates CUI, steel assets will reportedly last far longer before any steel needs to be replaced, if at all, minimizing the environmental costs of steel
production to maintain an asset. Finally, the consistent thermal efficiency Heat-Flex AEB offers allows asset owners to maintain required operating temperatures without needing to increase process heat inside the
coated asset.

A typical CUI-elimination coating system would include a primer applied directly to prepared steel to protect it from corrosion, the Heat-Flex AEB insulative coating on top of that and an optional topcoat layer. Recommended primers include Heat-Flex 750 — a high-solids alkylated amide epoxy coating featuring a high concentration of micaceous iron oxide pigment — as well as Heat-Flex ACE, an ultra-high solids epoxy novolac containing a functional chemical enhancement for CUI mitigation.

Applying Heat-Flex AEB is made easy, fast and safe. Unlike bulky insulation systems, which often require workers to wrap, band and cover insulation while in close proximity to hot assets, Sherwin-Williams says that a single applied coat of Heat-Flex AEB will instantaneously reduce the surface temperature, taking away the burn risk. Those assets can be operating up to 300°F (148°C) during coating applications, enabling processes to continue running without disrupting facility operations. Applications to new components can also take place in on-site pre-assembly yards rather than after assets are fully assembled.