UNE-EN ISO 5167-3:2023

This document specifies the geometry and method of use (installation and operating conditions) ofnozzles and Venturi nozzles when they are inserted in a conduit running full to determine the flowrateof the fluid flowing in the conduit.This document also provides background information for calculating the flowrate and is applicable inconjunction with the requirements given in ISO 5167-1.This document is applicable to nozzles and Venturi nozzles in which the flow remains subsonicthroughout 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 isnot applicable to the measurement of pulsating flow. It does not cover the use of nozzles and Venturinozzles in pipe sizes less than 50 mm or more than 630 mm, or where the pipe Reynolds numbers arebelow 10 000.This document deals witha) three types of standard nozzles:1) ISA 19321) nozzle;2) the long radius nozzle2);3) the throat-tapped nozzleb) the Venturi nozzle.The three types of standard nozzle are fundamentally different and are described separately in thisdocument. The Venturi nozzle has the same upstream face as the ISA 1932 nozzle, but has a divergentsection and, therefore, a different location for the downstream pressure tappings, and is describedseparately. This design has a lower pressure loss than a similar nozzle. For all of these nozzles and forthe Venturi nozzle direct calibration experiments have been made, sufficient in number, spread andquality to enable coherent systems of application to be based on their results and coefficients to begiven with certain predictable limits of uncertainty.