BS EN ISO 5167-5:2022 Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full. Cone meters
1 Scope
This document specifies the geometry and method of use (installation and operating
conditions) of cone meters when they are inserted in a conduit running full to determine
the flow rate of the fluid flowing in the conduit.
As the uncertainty of an uncalibrated cone meter might be too high for a particular
application, it might be deemed essential to calibrate the flow meter in accordance
with Clause 7.
This document also provides background information for calculating the flow rate and
is applicable in conjunction with the requirements given in ISO 5167‑1.
This document is applicable only to cone meters in which the flow remains subsonic
throughout the measuring section and where the fluid can be considered as single-phase.
Uncalibrated cone meters can only be used within specified limits of pipe size, roughness,
β , and Reynolds number, Re . This document is not applicable to the measurement of pulsating flow. It does not
cover the use of uncalibrated cone meters in pipes sized less than 50 mm or more than
500 mm, or where the pipe Reynolds numbers are below 8 × 10 4 or greater than 1,2 × 10 7 .
A cone meter is a primary device which consists of a cone-shaped restriction held
concentrically in the centre of the pipe with the nose of the cone upstream. The design
of cone meter defined in this document has one or more upstream pressure tappings
in the wall, and a downstream pressure tapping positioned in the back face of the
cone with the connection to a differential pressure transmitter being a hole through
the cone to the support bar, and then up through the support bar.