ISO 4267-2:1988

Overview

ISO 4267-2:1988 - "Petroleum and liquid petroleum products - Calculation of oil quantities - Part 2: Dynamic measurement" standardizes the terminology, equations and calculation procedures used for volumetric metering of liquid hydrocarbons (including liquefied petroleum gases) by meter and prover. It defines correction factors, the sequence and rules for applying them, rounding and significant-figure practices, and provides lookup tables where manual or computer calculation is not desired. Two‑phase fluids are excluded.

Key topics and technical requirements

• Terminology and definitions: precise terms such as base volume, indicated volume, meter factor, K‑factor, total/net standard volume, and measurement ticket.
• Standard reference conditions: default reference conditions are 15 °C and 101.325 kPa (with caveats for vapour‑pressure cases per ISO 5024).
• Principal correction factors: description and use of correction factors for
  • temperature effect on steel (Cts),
  • pressure effect on steel (Cps),
  • pressure effect on liquid (Cp),
  • temperature/density effect on liquid (Ctl),
  • sediment and water (Csw).
• Sequence and combination: rules to compute a combined correction factor (CCF) by multiplying individual factors in the specified sequence (MF, Cts, Cps, Cp, Ctl, Csw), with rounding at each step.
• Prover and meter calculations: procedures and example methods for calculating prover base volumes, calibrating pipe and tank provers (water‑draw, master‑meter), and determining meter factors and K‑factors.
• Accuracy hierarchy and rounding rules: defined hierarchy of accuracy levels, required significant figures and rounding/truncation rules for prover calibration, meter factors, K‑factors and measurement tickets.
• Reference tables and equations: provides equations and lookup tables for common correction factors to support manual and computer methods.

Applications and users

ISO 4267-2 is used where accurate volumetric metering and custody transfer of petroleum liquids are required. Typical users:

• custody transfer and terminal operators
• pipeline and distribution system engineers
• flow meter and prover calibration laboratories
• refinery and storage terminal measurement personnel
• instrumentation and metering consultants The standard helps ensure consistent, traceable calculations for meter calibration, prover calibration, ticketing and reporting.

Related standards

Relevant companion standards (referenced within ISO 4267-2) include:

• ISO 5024 - Standard reference conditions
• ISO 91-1 - Petroleum measurement tables
• ISO 2715 - Turbine meter volumetric measurement
• ISO 7278-2 - Proving systems for volumetric meters (pipe provers)
• ISO 8222 - Temperature corrections for volumetric reference systems
• ISO 9770 - Compressibility factors for hydrocarbons

Keywords: ISO 4267-2, dynamic measurement, petroleum metering, prover calibration, correction factors, meter factor, K-factor, volumetric measurement, custody transfer, measurement tickets.