用插入圆形横截面管道中的压差装置测量流体流量.第3部分:喷嘴和文丘里喷嘴

[中文适用范围]： 本文件规定了喷嘴和文丘里喷嘴插入完全运行的管道中时的几何形状和使用方法（安装和操作条件），以确定在管道中流动的流体的流量。 本文件还提供了计算流量的背景信息，并与 ISO 5167-1 中给出的要求结合应用。 本文件适用于喷嘴和文丘里喷嘴，其中流体在整个测量部分保持亚音速，并且流体可被视为单相。 此外，每个设备只能在指定的管道尺寸和雷诺数限制内使用。 不适用于脉动流量的测量。 它不涵盖管道尺寸小于 50 毫米或大于 630 毫米或管道雷诺数低于 10000 的喷嘴和文丘里喷嘴的使用。 本文件涉及 a) 三种类型的标准喷嘴： 1) ISA 19321 ）喷嘴； 2) 长半径喷嘴2); 3) 喉部攻丝喷嘴 b) 文丘里喷嘴。 这三种类型的标准喷嘴本质上是不同的，在本文档中分别进行了描述。 文丘里喷嘴与 ISA 1932 喷嘴具有相同的上游面，但具有发散部分，因此下游取压口的位置不同，因此单独描述。 这种设计比类似的喷嘴具有更低的压力损失。 对于所有这些喷嘴和文丘里喷嘴，已经进行了直接校准实验，其数量、范围和质量足以使连贯的应用系统能够基于其结果和系数，并在某些可预测的不确定性极限下给出。 [外文原描述]： This document specifies the geometry and method of use (installation and operating conditions) of nozzles and Venturi nozzles when they are inserted in a conduit running full to determine the flowrate of the fluid flowing in the conduit. This document also provides background information for calculating the flowrate and is applicable in conjunction with the requirements given in ISO 5167‑1. This document is applicable to nozzles and Venturi nozzles in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. In addition, each of the devices can only be used within specified limits of pipe size and Reynolds number. It is not applicable to the measurement of pulsating flow. It does not cover the use of nozzles and Venturi nozzles in pipe sizes less than 50 mm or more than 630 mm, or where the pipe Reynolds numbers are below 10 000. This document deals with a) three types of standard nozzles: 1) ISA 1932[1] nozzle; 2) the long radius nozzle[2]; 3) the throat-tapped nozzle b) the Venturi nozzle. The three types of standard nozzle are fundamentally different and are described separately in this document. The Venturi nozzle has the same upstream face as the ISA 1932 nozzle, but has a divergent section and, therefore, a different location for the downstream pressure tappings, and is described separately. This design has a lower pressure loss than a similar nozzle. For all of these nozzles and for the Venturi nozzle direct calibration experiments have been made, sufficient in number, spread and quality to enable coherent systems of application to be based on their results and coefficients to be given with certain predictable limits of uncertainty. [1] ISA is the abbreviation for the International Federation of the National Standardizing Associations, which was superseded by ISO in 1946. [2] The long radius nozzle differs from the ISA 1932 nozzle in shape and in the position of the pressure tappings.