scope:

This part of EN ISO 5167 specifies the geometry and method of use (installation and operating conditions) of Venturi tubes when they are inserted in a conduit running full to determine the flowrate of the fluid flowing in the conduit. This part of EN ISO 5167 also provides background information for calculating the flowrate and is applicable in conjunction with the requirements given in EN ISO 5167-1. This part of EN ISO 5167 is applicable only to Venturi tubes in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. In addition, each of these devices can only be used within specified limits of pipe size, roughness, diameter ratio and Reynolds number. This part of EN ISO 5167 is not applicable to the measurement of pulsating flow.