ISO 161-1:2018规定了压力和非压力应用中流体输送用公制热塑性塑料管的标称外径。它还规定了标称压力额定值和压力应用所需的最小强度。 ISO 161-1:2018适用于沿管道全长具有恒定圆形横截面的光滑热塑性塑料管，无论其制造方法或施工材料如何。 ISO 161-1:2018不适用于根据公称内径DN/ID指定的管道。 ISO 161-1:2018是标准编写者在起草产品标准时选择公称直径和公称压力的基础。

ISO 161-1:2018 specifies the nominal outside diameters for metric thermoplastics pipes for the conveyance of fluids in pressure and non-pressure applications. It also specifies nominal pressure ratings and minimum required strengths for pressure applications. ISO 161-1:2018 is applicable to smooth thermoplastics pipes of constant circular cross-section along the whole length of the pipe, whatever their method of manufacture or material of construction. ISO 161-1:2018 is not applicable to pipes designated according to the nominal inside diameter DN/ID. ISO 161-1:2018 is a basis for standards writers for the selection of nominal diameters and nominal pressures in the drafting of product standards.