1.1 本规程涵盖了隔热层的最大使用温度估算，包括松散填料、毯子、砌块、木板和预制管道隔热层。它基于选定的性能标准，以及使用条件期间和使用后产品特性的表征。 1.2 以英寸-磅单位表示的数值视为标准值。括号中给出的值是数学转换为SI单位，仅供参考，不被视为标准单位。 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 本规程旨在用作评估高温下绝缘性能以及判断在预期应用条件下适用性的指南。它不用于批量验收或认证测试。 5.2 不能使用适用于所有类型绝缘的估算最大使用温度的单一测试，也不能将任何单一最大使用温度应用于所有可能使用条件下适用的任何绝缘。 最大使用温度取决于厚度、温度梯度、加热速率和其他因素。当采用本文所列的各种试验方法时，试验结果可作为指导，因此，应用时应具有良好的工程判断，以达到所考虑产品和应用的可接受温度极限。 5.3 用于确定可接受性能的标准在材料规范中提供，或由买方和卖方商定。 5.4 在大多数情况下，适用材料标准所涵盖的特性（例如，热传导、强度等）是对产品最终用途至关重要的特性。由于运行条件而导致的这些特性的重大变化通常会导致已安装系统的故障或性能不合格。 5.5 除非拆除和重新使用绝缘层是一个重要考虑因素，否则应在评估中排除主要与搬运和安装相关的特性。 注1: 安装组件:一些系统会根据本规程测试程序中获得的数据产生影响性能的条件。 5.6 本规程中列出的测试程序并不意味着需要执行该特定程序。仅进行与所涉及应用要求相关的测试，或买方和卖方同意的测试。 5.7 在使用过程中，所有类型隔热材料的重要功能特性发生的大多数变化首先是由于基质或粘结剂系统的变化，其次是使用此类填料的散装填料的变化。 5.7.1 通常，这些变化取决于温度，一旦达到临界温度，变化的主要部分就会迅速发生。 5.7.2 通常，有机热塑性材料或粘合剂将在140 °F至240 华氏度（60 °C至116 °C）温度范围。热固性有机材料或粘合剂在350以上将开始变质 华氏度（177 °C）。水合无机粘结剂，如粘土、波特兰和褐铁矿水泥、石膏、硅酸钠、氧硫酸盐和氧氯化物，在250℃以下会损失不同数量的结晶水 °F至900 华氏度（121 °C至482 °C）取决于化合物。玻璃纤维和玻璃泡沫开始烧结约1000 华氏度（538 °C）。岩石或矿渣棉、珍珠岩和耐火纤维在温度超过1300℃时偶尔会出现变化 华氏度（704 °C）。 5.8 如果在试样暴露于最高工作温度后，对暴露于中间温度（全工作温度范围内的第三个或四分之一点）的试样进行附加试验，则当使用适当的曲线拟合技术绘制此类试验的结果时，可显示整个工作范围内产品特性的变化。这些结果用于界定发生变化的温度范围（例如，曲线斜率的显著变化）。 5.9 含有除空气以外的捕获气体的隔热材料的某些特性随时间以不同的速率变化，具体取决于龄期、厚度、饰面和边界条件。高温暴露通常会加速这些变化。在许多情况下，房地产的变化会持续很长一段时间。 确定评估长期变化的最短时间段超出了本建议做法的范围。

1.1 This practice covers estimation of the maximum use temperature of thermal insulation including loose fill, blanket, block, board, and preformed pipe insulation. It is based upon selected performance criteria, and characterization of product properties during and after use conditions. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This practice is intended for use as a guide in evaluating the behavior of insulations at elevated temperatures, and in judging suitability for use under the conditions of an intended application. It is not intended for acceptance or certification testing on a lot basis. 5.2 No single test for estimating maximum use temperature can be used that will apply to all types of insulations, nor can any single maximum use temperature be applied to any insulation that will be applicable under all possible conditions of use. Maximum use temperature depends on thickness, temperature gradient, heating rate, and other factors. When the various test methods listed herein are employed, the test results serve as guides and, as such, shall be applied with good engineering judgment in arriving at an acceptable temperature limit for the products and applications being considered. 5.3 The criteria used to establish acceptable performance is provided in the material specification or as agreed upon by the purchaser and seller. 5.4 In most cases, the properties covered by the applicable material standards (for example, thermal transmission, strength, and so forth) are the properties important to the end use of the product. Major changes in those properties resulting from in-service conditions often causes failure or substandard performance of the installed system. 5.5 Unless removal and reuse of the insulation is an important consideration, properties that relate primarily to handling and installation shall be eliminated from the evaluation. Note 1: Installation assemblies: some systems create conditions that affect the performance from the data obtained in the test procedures of this practice. 5.6 The listing of a test procedure in this practice does not imply that the performance of that particular procedure is required. Only those tests which are relevant to the requirements of the application involved, or which are agreed upon by the purchaser and the seller are preformed. 5.7 Most of the changes that occur in the functionally important characteristics of all types of thermal insulation during service result from changes in the matrix or binder system first, followed by changes in the bulk filler materials where such fillers have been used. 5.7.1 In general, these changes are temperature-dependent and the major portion of the change takes place quickly once the critical temperature has been reached. 5.7.2 Typically, organic thermoplastic materials or binders will change in the 140 °F to 240 °F (60 °C to 116 °C) temperature range. Thermosetting organic materials or binders will start to deteriorate above 350 °F (177 °C). Hydrated inorganic binders such as clays, Portland and lumnite cements, gypsum, sodium silicates, oxysulfates, and oxychlorides lose varying amounts of water of crystallization at temperatures from 250 °F to 900 °F (121 °C to 482 °C) depending on the compound. Glass fibers and glass foams start to sinter around 1000 °F (538 °C). Rock or slag wools, perlite and refractory fibers occasionally show change at temperatures in excess of 1300 °F (704 °C). 5.8 If, after testing specimens exposed to the maximum service temperature, additional tests are made of specimens exposed to intermediate temperatures (third or quarter points in the full service temperature range), the results of such tests, when plotted with proper curve-fit techniques, give indications of changes in product characteristics throughout the service range. These results are used to bracket the temperature range within which a change has occurred (for example, significant change in slope of curve). 5.9 Some properties of thermal insulations containing trapped gases other than air change with time at different rates depending on the age, thickness, facing and boundary conditions. Elevated temperature exposure often accelerates these changes. In many cases changes in properties continue over a very long period of time. It is beyond the scope of this recommended practice to establish a minimum time period for evaluation of long-term changes.