EN764-1中3.18的nominal size是什么意思? numerical designation of size which is common to all components in a piping system other than components indicated by outside diameters or by thread size. it is a convenient round number for reference purposes and is only loosely related to manufacturing dimensions 只为试译:用数字标注管路系统中的所有部件的尺寸,而不是由外径或者是螺纹尺寸标注。数字为整数,只作为参考,与实际生产尺寸仅为大致关联关系查看更多