ISO 22391-3:2009规定了耐高温聚乙烯（PE-RT），耐高温聚乙烯（PE-RT），类型II的热塑性弹性体（PE-RT）以及在适用于根据ISO 22391-1的适用类别的设计压力和温度下，无论水是否用于人类消费（家庭系统）和供暖系统，建筑物内的冷水设施都是用于运输水的。 ISO 22391-3:2009涵盖了一系列服务条件（应用类别），设计压力和管道尺寸等级，并且还规定了测试参数和测试方法。结合ISO 22391的其他部分，它适用于由PE-RT制成的配件，以及适用于符合ISO 22391-2标准的热水和冷水装置的管道的其他材料制成的配件，其接头符合ISO 22391-5。 适用于以下类型的配件: - 机械配件; - 插座熔接; - 电熔配件; - 配有插入件的配件

ISO 22391-3:2009 specifies the characteristics of fittings for piping systems made of polyethylene of raised temperature resistance (PE-RT), Type I and polyethylene of raised temperature resistance (PE-RT), Type II, intended to be used for hot and cold water installations within buildings for the conveyance of water, whether or not the water is intended for human consumption (domestic systems) and for heating systems, under the design pressures and temperatures appropriate to the class of application according to ISO 22391-1. ISO 22391-3:2009 covers a range of service conditions (classes of application), design pressures and pipe dimension classes, and also specifies test parameters and test methods. In conjunction with the other parts of ISO 22391, it is applicable to fittings made of PE-RT, as well as to those made of other materials, intended to be fitted to pipes conforming to ISO 22391-2 for hot and cold water installations, the joints of which are in accordance with ISO 22391-5. It is applicable to the following types of fitting: - mechanical fittings; - socket fusion fitting; - electrofusion fittings; - fittings with incorporated inserts.