本文件描述了炼油厂和其他相关行业和环境中的各种绝缘下腐蚀（CUI）环境，并确定了CUI环境类别，包括仅适用于上部组块和地上服务的工作温度范围为？45°C至204°C。本文件规定了用于评估每个给定环境中用于预防CUI的涂层的既定试验方法和其他试验方法。本文件还提供了每个CUI环境的验收标准。 注:试验结果和验收标准可被视为有助于选择合适的涂层系统。对于低于45°C的服务温度或峰值温度，可采用可选的低温试验，对于超过204°C的试验，相关方可商定验收标准。可以采取额外或其他测试和验收措施，但需要相关方之间达成特别协议。 本文件涵盖了用于CUI服务的新型碳钢和奥氏体不锈钢上的喷涂涂层。本文件不包括无机锌等牺牲涂层的测试，因为这些涂层在潮湿环境中会很快消耗。为具有牺牲涂层的连续湿服务开发加速腐蚀试验超出了本文件的范围。 干膜厚度大于250μm的“非穿透孔隙率”热喷涂铝涂层可根据本文件进行测试和鉴定。本文件不包括用于防止CUI的胶带和薄板应用产品。 本文件不涉及涂层降解的其他方面，例如磨损、侵蚀、紫外线降解或特定环境和施工方法下可能存在的其他方法引起的涂层降解。

This document describes various corrosion under insulation (CUI) environments in refineries and other related industries and environments, and establishes CUI environmental categories including operating temperature ranges from？45 °C to 204 °C for topside and aboveground service only. This document specifies both established and other test methods for the assessment of coatings used for prevention of CUI for each given environment. This document also provides acceptance criteria for each CUI environment. NOTE The test results and acceptance criteria can be considered an aid in the selection of suitable coating systems. For service or peak temperatures below？45 °C an optional cryogenic test can be incorporated and for over 204 °C testing acceptance criteria can be agreed between interested parties. Additional or other test and acceptance measures are possible, but require particular agreement between the interested parties. This document covers spray-applied coatings applied on new carbon and austenitic stainless steel for use in CUI service. This document does not cover testing of sacrificial coatings, such as inorganic zinc, as these coatings can be consumed quickly in wet environments. Developing accelerated corrosion testing for what can be continuous wet service with sacrificial coatings is beyond the scope of this document. "Non-through porosity" thermal spray aluminium coatings with greater than 250 μm dry film thickness can be tested and qualified in accordance with this document. This document does not cover tape and sheet applied products for use in preventing CUI. This document does not deal with other aspects of coating degradation, such as those caused by abrasion, erosion, ultraviolet degradation or other methods that can exist given specific environment and construction methods.