Thermal insulation is critical in many pipeline operations, but it comes with a risk that can create serious trouble for operators. When moisture becomes trapped between the insulation and the metal surface, it can lead to what’s known as corrosion under insulation (CUI). CUI corrosion rates are approximately 20 times faster<\/a> than atmospheric corrosion rates, with metal loss rates reaching up to 3 mm annually because CUI damage can go unnoticed until it is too late.<\/p>\r\n CUI encompasses numerous corrosion mechanisms. These include general carbon steel corrosion, external chloride stress corrosion cracking<\/a> on austenic stainless steels such as TP304 and TP316, and galvanic corrosion where dissimilar metals make contact under wet insulation. Each of these mechanisms requires a different detection and mitigation strategy. The ASTM C692 standard<\/a> in particular addresses evaluating the influence of thermal insulations on external stress corrosion cracking tendency of austenic stainless steel.<\/p>\r\n SMARTCORR\u00ae provides an integrated approach to corrosion management. We combine combining Ultrasonic Guided Wave (UGW) detection<\/a>, corrosion monitoring systems, and data-driven management through SCEMS software to create a comprehensive CUI management solution that addresses detection, monitoring, and corrosion prevention under one roof.<\/p>\r\n There are four main factors that drive CUI:<\/p>\r\n Equipment that alternates between operating and ambient temperatures are most vulnerable to these factors. Wet-dry conditions under cyclic temperatures have been found to cause higher rates of corrosion<\/a> than those under constant temperatures. This is because thermal cycling drives condensation and moisture accumulation under the insulation. In many cases, CUI can be accelerated<\/a> when insulated equipment is operated under cyclic temperature and wet-dry cycles.<\/p>\r\n Working with SMARTCORR\u00ae means gaining systemic identification of CUI-susceptible circuits during the design phase of the pipeline. This means operators can specify the most appropriate insulation materials, coating systems, and monitoring points before corrosion has a chance to occur.<\/p>\r\n Because it is out of sight, CUI can be inherently difficult to detect. Operators are unable to see, measure, or assess metal loss without removing the insulation completely or deploying specific non-destructive testing methods. More than 60% of pipe failures<\/a> can be attributed to CUI, which makes the importance of early detection extremely high.<\/p>\r\n Early detection is critical, as the economic impact of corrosion is estimated to be as much as $2.5 trillion every year<\/a>. ExxonMobil has determined that nearly half of all pipework maintenance costs are due to CUI<\/a>, and a single hour of downtime is estimated to cost oil and gas facilities nearly $500,000<\/a>.<\/p>\r\n With Ultrasonic Guided Wave technology from SMARTCORR\u00ae, operators can detect CUI from a single access point. This technique provides 100% cross-section coverage with 1% metal loss precision over long ranges without requiring insulation removal.<\/p>\r\n The seven main forms of CUI detection are:<\/p>\r\n When selecting a detection method, operators should pay attention to factors such as whether they’re screening or sizing corrosion, the insulation type and thickness, pipe diameter range, budget constraints, and whether the facility can accommodate insulation removal. Most operators choose a tiered approach that combines screening methods such as PEC and UGW with follow-up sizing methods like radiography.<\/p>\r\n SMARTCORR\u00ae’s UGW non-destructive testing detects CUI from a single point, with 100% cross-section coverage and 1% metal loss precision over long distances. This is complemented by our ILI services for pipelines and AI-powered data analysis that automates defect identification.<\/p>\r\n CUI prevention takes many forms. For example, there are three main approaches that utilize protective coatings:<\/p>\r\n There are some design considerations that can be used to fight CUI, as well:<\/p>\r\n SMARTCORR\u00ae takes an integrated approach to CUI prevention. We provide Corrosion Design Memorandums (CDM) that specify coating systems, insulation materials, and monitoring requirements during facility design. We combine this with ongoing monitoring services through ER probes and LPR probes at areas susceptible to CUI. The data is fed to our SCEMS software platform for early trend detection before wall loss reaches actionable thresholds.<\/p>\r\n The level of CUI risk operators face can vary a lot with the sector. For example, downstream refineries face the highest CUI burden thanks to extensive insulated piping, vessels, and heat exchangers operating in CUI-critical temperature ranges under OSHA PSM requirements. This is why the petrochemical industry spends roughly 10% of its maintenance and repair budget<\/a> on piping systems and pressure vessels due to CUI.<\/p>\r\n Midstream pipeline operators have to manage CUI at compressor stations, metering stations, and above-ground crossings as regulated by PHMSA 49 CFR 192\/195. Petrochemical plants must deal with CUI on reactor piping and cryogenic\/hot service alternating systems, while offshore platforms face higher CUI exposure due to marine salt spray exposure.<\/p>\r\n The management standards for CUI often span multiple regulatory frameworks. These include API RP 583<\/a> for the design, maintenance, and inspection of processing equipment. NACE SP0198<\/a> addresses the control of corrosion under thermal insulation and fireproofing materials. In addition, API 570, API 510, and ASTM standards cover insulation materials.<\/p>\r\n SMARTCORR\u00ae has experience serving operators across all these sectors and more. Our client base includes names such as ExxonMobil, BP, Shell, and Halliburton. Our integrated CUI management programs combine UGW inspection, corrosion monitoring, cathodic protection<\/a> (for external surfaces), and SCEMS-driven data analysis to prioritize inspection and maintenance spending based on actual corrosion data rather than time-based schedules.<\/p>\r\n Risk-based inspection (RBI) can transform CUI management from blanket insulation-removal programs that are expensive and disruptive to targeted inspection strategies that concentrate resources on the circuits that are at the highest risk. Here is a quick overview of the lifecycle of a CUI management program utilizing RBI:<\/p>\r\n SMARTCORR\u00ae provides full lifecycle CUI management, including:<\/p>\r\n All these services for managing corrosion are delivered under triple ISO certification (9001, 14001, 45001) with zero reportable safety incidents over 1.5 million hours worked. We also provide full compliance with NACE<\/a>, ANSI, ASTM<\/a>, API<\/a>, and ASME standards across all product lines and services. We also have a workforce where more than 50% hold master’s degrees or higher, ensuring that CUI management programs meet the technical rigor required by these overlapping frameworks. To learn more, reach out to us today.<\/p>","protected":false},"excerpt":{"rendered":" What Is Corrosion Under Insulation (CUI) and Why Is It a Critical Integrity Threat? Thermal insulation is critical in many pipeline operations, but it comes with a risk that can create serious trouble for operators. When moisture becomes trapped between the insulation and the metal surface, it can lead to what’s known as corrosion under … Corrosion Under Insulation: Causes, Detection, and Prevention<\/span><\/a><\/p>\n","protected":false},"featured_media":4283,"template":"","blog_category":[],"class_list":["post-4519","blog","type-blog","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/blog\/4519","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/types\/blog"}],"version-history":[{"count":1,"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/blog\/4519\/revisions"}],"predecessor-version":[{"id":4520,"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/blog\/4519\/revisions\/4520"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/media\/4283"}],"wp:attachment":[{"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/media?parent=4519"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/smartcorrs.com\/ar\/wp-json\/wp\/v2\/blog_category?post=4519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Four Factors That Cause Corrosion Under Insulation \u2014 and How to Identify Them Early<\/h2>\r\n
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The True Cost of Undetected CUI \u2014 and Why Early Detection Saves More Than Money<\/h2>\r\n
Seven CUI Detection and Inspection Methods: How Each Works, When to Use It<\/h2>\r\n
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How to Prevent CUI: Coatings, Design, and Material Selection That Protects Your Assets<\/h2>\r\n
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CUI Risk by Sector: How Refineries, Pipelines, Petrochemical Plants, and Offshore Facilities Differ<\/h2>\r\n
Your Six-Step Path from CUI Risk Assessment to Continuous Monitoring<\/h2>\r\n
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