It is an integer which is a little different from practical diameter. It is divided into reduced bore, non-reduced bore, full bore and flow diameter by different valve, nominal Preassure, spec sizes.
公称通径是一个圆整数它和实际通径不完全相同，它以不同形式的阀门和不同公称压力、不同规格尺寸来划分为缩径、不缩径及全通径、流通直径。
The PTFE tube comprises external roots and peaks, which tube is obtainable from a non-convoluted tube having an original wall thickness W0 and an internal diameter ID by a process in which a region of the tube is thinned to provide external convolutions with a root wall thickness W1 characterised in that the convoluted PFTE tube has an improved resistance, of greater than 7.6%, to permeation by comparison with the non-convoluted tube, the comparison being made between tubes of equal nominal bore ID; and equal weight of PTFE per unit length.
该PTFE管包括外部的根部和凸出部，该管可由初始壁厚为W0且内径为ID的无旋绕波纹管通过处理制成，在该处理中，使管的一些区域变薄，以便提供根部壁厚为W1外部旋绕波纹，其特征在于：与无旋绕波纹的管相比，该旋绕波纹PTFE管的抗渗透性提高了7.6％以上，该对比是在这样的管之间进行的：标称孔径ID相等；以及单位长度的PTFE的重量相等。
The parameters studied include the velocity of deflagration flame in smooth bore tube, the influence of nominal ignition energy on flame acceleration and the generation of high flame velocity.
以上研究也涉及了非稳定爆轰波的火焰面在直管道中的加速运动。