EN ISO 5167-5:2022 PDF

Overview

EN ISO 5167-5:2022 (ISO 5167-5:2022) defines the geometry and method of use for cone meters - a class of differential-pressure primary devices - when inserted in circular cross‑section conduits running full to determine fluid flow rate. The standard covers device shape, pressure tapping arrangements, installation and operating conditions, calculation background (discharge coefficient and expansibility factor), and guidance on uncertainty. It applies to subsonic, single‑phase flows and is intended to be used together with ISO 5167‑1 and other parts of the ISO 5167 series.

Key topics and requirements

• Cone meter geometry and pressure tappings
  • Cone held concentrically with the cone nose upstream.
  • One or more upstream wall tappings; downstream tapping in the cone back face with a thru‑cone connection to the support bar.
  • Alternative cone designs require laboratory calibration (Clause 7) due to limited characterization data.
• Limits of use for uncalibrated meters
  • Uncalibrated cone meters may only be used within specified limits of pipe size (50–500 mm), pipe roughness, diameter ratio β, and Reynolds number (Re between 8×10^4 and 1.2×10^7). Not applicable to pulsating flow.
• Flow computation parameters
  • Discharge coefficient (C): specified method for determining C and its uncertainty; can be improved via calibration.
  • Expansibility (expansion) factor (ε): tables and uncertainty guidance provided for compressible fluids.
• Installation and operating conditions
  • Minimum upstream/downstream straight lengths for common upstream disturbances (bends, valves, expanders).
  • Pipe circularity/cylindricity, surface roughness, and thermowell positioning requirements to ensure measurement accuracy.
• Calibration and uncertainty
  • Clause 7 outlines flow calibration procedures, test‑facility requirements, test program design, result reporting, and uncertainty analysis following ISO/IEC Guide 98‑3 principles.

Applications and users

Who uses EN ISO 5167-5:

• Flow measurement and metrology engineers
• Calibration laboratories and test facilities
• Manufacturers of differential‑pressure flow meters and cone meters
• Process engineers in water, wastewater, chemical, oil & gas and utility pipelines
• Companies implementing flow custody transfer or process control where primary device standards are required

Practical value:

• Provides repeatable, standardized methods for differential pressure flow measurement using cone meters
• Enables consistent estimation of flow rate and measurement uncertainty
• Supports selection, installation, and calibration strategies to meet regulatory, commercial, and process‑control requirements

Related standards

• ISO 5167‑1 (general principles and computation) - use in conjunction with Part 5
• Other parts of the ISO 5167 series (orifice plates, nozzles, Venturi tubes, wedge meters)
• ISO 2186 (secondary devices) and ISO/IEC Guide 98‑3 (uncertainty evaluation) for related metrology guidance

Keywords: EN ISO 5167-5:2022, ISO 5167-5, cone meter, differential pressure, flow measurement, discharge coefficient, expansibility factor, flow calibration, Reynolds number, pressure tappings.