DIN EN ISO 9300:2005
Measurement of gas flow by means of critical flow Venturi nozzles (ISO 9300:2005); English version of DIN EN ISO 9300

Standard No.

DIN EN ISO 9300:2005

Release Date

2005

Published By

German Institute for Standardization

Status

Be replaced

Replace By

DIN EN ISO 9300:2005-11

Latest

DIN EN ISO 9300:2023-11

Replace

DIN EN ISO 9300:1995

Scope

This International Standard specifies the geometry and method of use (installation in a system and operating conditions) of critical flow Venturi nozzles (CFVN) used to determine the mass flow-rate of a gas flowing through a system. It also gives the information necessary for calculating the flow-rate and its associated uncertainty. It is applicable to Venturi nozzles in which the gas flow accelerates to the critical velocity at the throat (this being equal to the Focal sonic velocity), and only where there is steady flow of single-phase gases. At the critical velocity, the mass flow-rate of the gas flowing through the Venturi nozzle is the maximum possible for the existing upstream conditions while CFVN can only be used within specified limits, e.g. limits for the nozzle throat to inlet diameter ratio and throat Reynolds number. This International Standard deals with CFVN for which direct calibration experiments have been made in sufficient number to enable the resulting coefficients to be used with certain predictable limits of uncertainty. Information is given for cases where the pipeline upstream of the CFVN is of circular cross-section, or it can be assumed that there is a large space upstream of the CFVN or upstream of a set of CFVN mounted in a cluster. The cluster configuration offers the possibility of installing CFVN in parallel, thereby achieving high flow-rates. For high-accuracy measurement, accurately machined Venturi nozzles are described for Iow Reynolds number applications.

DIN EN ISO 9300:2005 history

• 2023 DIN EN ISO 9300:2023-11 Measurement of gas flow by means of critical flow nozzles (ISO 9300:2022); German version EN ISO 9300:2022
• 2023 DIN EN ISO 9300:2023 Measurement of gas flow by means of critical flow nozzles (ISO 9300:2022)
• 2021 DIN EN ISO 9300:2021-09 Measurement of gas flow by means of critical flow nozzles (ISO/DIS 9300:2021); German and English version prEN ISO 9300:2021 / Note: Date of issue 2021-07-30*Intended as replacement for DIN EN ISO 9300 (2005-11).
• 2005 DIN EN ISO 9300:2005-11 Measurement of gas flow by means of critical flow Venturi nozzles (ISO 9300:2005); German version EN ISO 9300:2005 / Note: To be replaced by DIN EN ISO 9300 (2021-09).
• 2005 DIN EN ISO 9300:2005 Measurement of gas flow by means of critical flow Venturi nozzles (ISO 9300:2005); English version of DIN EN ISO 9300
• 1995 DIN EN ISO 9300:1995 Measurement of gas flow by means of critical flow Venturi nozzles