ISO 10976-2023 PDF

Full title and description

ISO 10976:2023 — Refrigerated light hydrocarbon fluids — Measurement of cargoes on board LNG carriers. This international standard specifies procedures, measurement systems and accounting methods for determining the quantity of refrigerated light hydrocarbon fluids (notably liquefied natural gas, LNG) carried on LNG carriers, intended to support consistent and reliable cargo measurement for operational control and custody transfer.

Abstract

ISO 10976:2023 establishes the measurement principles and practical steps required to quantify cargo on board LNG carriers. It covers measurement of liquid and vapour volumes, temperature and pressure measurement, density and mass determinations, volume correction and correction factors, metering and gauging systems, calibration and verification, uncertainty assessment, and documentation and reporting necessary to account for cargo quantities accurately for operational and commercial purposes.

General information

• Status: Published
• Publication date: August 2023 (3rd edition).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.180.30 (Volume measurement and equipment for liquid hydrocarbons).
• Edition / version: Edition 3 (2023).
• Number of pages: 64 (official ISO edition).

Scope

This standard applies to the measurement and accounting of refrigerated light hydrocarbon fluids carried as cargo on board LNG carriers. It specifies requirements for onboard measurement systems and procedures used to determine liquid and vapour quantities, corrections for temperature and pressure, determination of density and mass, calibration and verification of instruments, calculation methods for volume correction factors, handling of sloshing and stratification effects where relevant, and record keeping needed for custody transfer and operational monitoring. It is intended for use by ship operators, cargo surveyors, terminal operators and other parties involved in the LNG supply chain.

Key topics and requirements

• Definitions and terminology for refrigerated light hydrocarbon fluids and LNG cargo measurement.
• Requirements for onboard measurement systems: level gauging, flowmeters, temperature and pressure sensors, and density measurement devices.
• Procedures for liquid and vapour volume determination, ullage and tank calibration reference tables.
• Methods for temperature and pressure measurement and application of volume correction factors to obtain standardized quantities.
• Guidance on mass and density calculations, including use of reference density tables and algorithms.
• Calibration, verification and routine testing of measurement equipment and instrumentation.
• Approach to estimating and reporting measurement uncertainty and its impact on custody transfer.
• Data recording, reporting formats and documentation required for cargo accounting and dispute resolution.
• Operational considerations for loading, unloading, and tank handling to ensure measurement integrity.

Typical use and users

ISO 10976:2023 is used by LNG ship operators, cargo surveyors and inspectors, terminal and port operators, metrology and calibration laboratories, classification societies, marine engineers, LNG traders and anyone involved in custody transfer, commercial accounting or regulatory compliance for LNG cargoes transported by sea. It is also referenced by equipment manufacturers and system integrators designing onboard measurement and monitoring systems.

Related standards

This standard replaces earlier editions of ISO 10976 (for example the 2015 edition) and is developed under ISO/TC 28/SC 5 (measurement of liquid hydrocarbons). Related documents typically referenced in this field include other ISO standards and international or industry guidance on custody transfer and volumetric corrections for cryogenic hydrocarbons, as well as national and industry standards and practices (for example standards and manuals addressing LNG measurement and custody transfer from recognised industry bodies). Users should consult the normative references listed in the standard for precise cross-references.

Keywords

LNG, refrigerated light hydrocarbon fluids, cargo measurement, custody transfer, ullage, volume correction factor, density, mass determination, tank gauging, flowmeters, calibration, measurement uncertainty, shipboard measurement systems.

FAQ

Q: What is this standard?

A: ISO 10976:2023 is an international standard that specifies procedures and technical requirements for measuring and accounting for refrigerated light hydrocarbon fluids (notably LNG) carried on board LNG carriers.

Q: What does it cover?

A: It covers onboard measurement systems and methods for determining liquid and vapour volumes, temperature and pressure measurement, density and mass calculations, calibration and verification of instruments, correction factors and uncertainty assessment, plus documentation and reporting for operational and commercial use.

Q: Who typically uses it?

A: Ship operators, cargo surveyors, terminal operators, metrology and calibration labs, classification societies, equipment manufacturers, marine engineers and traders involved in the handling, measurement and custody transfer of LNG cargoes.

Q: Is it current or superseded?

A: It is current — published in August 2023 as the third edition. It supersedes the previous edition of ISO 10976 (2015).

Q: Is it part of a series?

A: ISO 10976 is part of ISO work addressing measurement and handling of hydrocarbon liquids under the responsibility of ISO/TC 28 and its subcommittee on measurement of liquid hydrocarbons; it should be used alongside other ISO and industry standards dealing with custody transfer, metrology and instrumentation for cryogenic liquids.

Q: What are the key keywords?

A: LNG, refrigerated light hydrocarbon fluids, cargo measurement, custody transfer, ullage, volume correction factors, density, tank gauging, calibration, measurement uncertainty.