DIN EN ISO 5167-5:2016-10

ISO 5167 is divided into five parts and covers the geometry and method of use (installation and operating conditions) of orifice plates, nozzles, Venturi tubes and cone flow meters (cone meters) when they are inserted in a conduit running full to determine the flow rate of the fluid flowing in the conduit. It also gives necessary information for calculating the flow rate and its associated uncertainty. ISO 5167 is applicable only to pressure differential devices in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase, but is not applicable to the measurement of pulsating flow. Furthermore, each of these devices can only be used within specified limits of pipe size and Reynolds number, or alternatively they can be used across their calibrated range. ISO 5167 deals with devices for which 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. However, a wide range of nominal pipe size and Reynolds number may be considered for cone flow meters calibrated in accordance with Section 7. Flow meters installed in pipelines are referred to as "primary devices". The designation primary device also includes the pressure taps (pressure measurement points). Any other measuring devices or equipment required to determine flow are referred to as "secondary devices". ISO 5167 applies only to primary devices; secondary devices are mentioned only occasionally. This part of ISO 5167 specifies the geometry and application procedures (installation and operating conditions) of cone flow meters in a conduit running full to determine the flow rate of the fluid flowing in the conduit.