ISO 28721-3:2008规定了主要用于化工厂工艺设备的搪玻璃设备、组件、附件和管道的抗热震性要求以及加热和冷却程序。 它使用图表规定了抗热震性的极限。对于搪玻璃钢而言，搪玻璃一侧的热冲击（通过给设备充电产生）和钢一侧的热冲击（通过加热或冷却设备产生）是有区别的。 ISO 28721的本部分适用于-25°C至+230°C的工作温度。 它仅适用于搪瓷非合金和低合金碳钢。

ISO 28721-3:2008 specifies requirements for the thermal shock resistance of, and heating and cooling procedures for, glass-lined apparatus, components, accessories and pipes primarily used for process equipment in chemical plants. It specifies the limits of thermal shock resistance using diagrams. For glass-lined steel, a distinction is made between a thermal shock on the glass-lined side (produced by charging an apparatus) and a thermal shock on the steel side (produced by heating or cooling an apparatus). This part of ISO 28721 applies to operating temperatures from - 25 °C to + 230 °C. It is only applicable to enamelled unalloyed and low-alloy carbon steels.