Corrosion Under Insulation (CUI) is an established and well-recognized problem for industrial facilities, with serious risks to health, safety and the environment.
Unquestionably, CUI is a crucial issue for facility owners, operators and service providers alike.
Strategies for preventing or mitigating the effects of CUI require a systems approach, a key component of which is the choice of insulation material. Certain insulation products provide additional protections for mitigating CUI. A common category of insulation materials specified for use in areas at high risk for CUI are hydrophobic insulations. Given that ingress of water into insulation systems is the primary driver of CUI, the ability of an insulation to repel water, and to prevent wicking of water, serves to passively defend against CUI.
However, no matter how good the design of the insulation system or how thorough the maintenance and inspection practices, moisture is bound to find its way into the system. As the industry adage goes, it is not "if" the water will get into the system, it is "when." For over four decades, perlite silicate insulation has proven highly effective in protecting against CUI by combining the passive protection afforded by hydrophobicity with the active protection granted by an inherent chemistry that inhibits corrosion.
Perlite silicate is a rigid, pre-molded insulation that has amassed decades of experience in some of the harshest, most CUI-prone environments. The incorporation of a hydrophobe along with the non-wicking nature of perlite silicate allows the insulation to shed bulk water and prevents the insulation from trapping moisture up against the external surfaces of piping and equipment. Furthermore, perlite silicate contains soluble silicates, which when challenged by moisture have been shown to form a protective layer on metal surfaces that actively inhibits corrosion throughout the installed lifetime.
A vast amount of real-world data supports perlite silicate insulation's efficacy in mitigating CUI. While investigating a catastrophic incident that occurred in a chemical facility in 2006, investigators noted that the critical failure occurred not at the typically high-risk point - the pipe fittings - but on top of a straight run pipe. The pipe, insulated with a rigid insulation known to absorb and hold water, had suffered corrosion that resulted in the loss of nearly 95% of its original wall thickness. Conversely, the pipe fittings had been insulated with SMC's perlite silicate and were found to be in excellent condition, despite their location at a notoriously problematic point in industrial insulation systems.
Perlite silicate remains an industry standard for efficient and effective thermal insulation. Recently, a new reinforced perlite silicate, AU-1200, has been introduced to the market, offering the proven benefits of perlite silicate in a new format that is strong, robust and easily handled. This patented, reinforced perlite silicate, manufactured by SMC Industries in Houston, is available in pipe and block, alongside small and large bore pre-molded fittings, offering a turnkey, ready-to-install insulation system with a proven track record of combatting CUI.
For more information, visit smcindustries.com or call (281) 860-9950.
