ISO 21003-5:2008规定了多层管道系统的适用性特征，该多层管道系统拟用于建筑物内的热水和冷水输送装置，无论水是否拟用于人类消费（家用系统）或供暖系统，其适用于指定的设计压力和温度，适用于应用 它还规定了ISO 21003本部分所述试验方法的试验参数。 ISO 21003是一个参考产品标准。它适用于多层管道、管件及其接头，也适用于与其他塑料和非金属材料制成的部件的接头- 用于热水和冷水装置的塑料材料。ISO 21003-5仅与ISO 21003的所有其他部分一起使用。

ISO 21003-5:2008 specifies the characteristics for the fitness for purpose of multilayer piping systems intended to be used for hot and cold water installations inside buildings for the conveyance of water — whether or not the water is intended for human consumption (domestic systems) or for heating systems — under specified design pressures and temperatures appropriate to the class of application. It also specifies the test parameters for the test methods referred to in this part of ISO 21003. ISO 21003 is a reference product standard. It is applicable to multilayer pipes, fittings, their joints, and also to joints with components made of other plastics and non-plastics materials intended to be used for hot and cold water installations. ISO 21003-5 is intended for use only in conjunction with all the other parts of ISO 21003.