Homechevron_rightStandardschevron_rightISO 21903:2020

ActiveInternational Standardupdate Standard Updated: February 2020fact_check Fact checked: Jun 28, 2026

ISO 21903:2020

Refrigerated hydrocarbon fluids — Dynamic measurement — Requirements and guidelines for the calibration and installation of flowmeters used for liquefied natural gas (LNG) and other refrigerated hydrocarbon fluids

apartmentPublishing Organization:International Organization for Standardization (ISO)

Global Services Energy

Standard Introduction

ISO 21903:2020 is an active standard published by International Organization for Standardization (ISO). It is commonly used across Services, Energy and applies in Global.

Use this page to review the official documentation, current status, and the certification or assessment bodies most commonly associated with ISO 21903:2020.

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Environmental Performance

ISO 21903:2020 provides a structured reference for refrigerated hydrocarbon fluids — dynamic measurement — requirements and guidelines for the calibration and installation of flowmeters used for liquefied natural gas (lng) and other refrigerated hydrocarbon fluids, helping organizations translate the standard into scope, responsibilities, controls, and evidence.

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Evidence and Control Alignment

Connects policies, operational controls, records, monitoring, and corrective actions so implementation can be reviewed by internal teams, customers, auditors, or regulators.

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Continual Improvement

Supports recurring review of objectives, risks, performance, incidents, stakeholder expectations, and improvement actions as the organization changes.

list_alt Implementation Focus Areas

Scope and organizational context
Leadership, ownership, and policy alignment
Risk, obligation, or process assessment
Operational controls and documented procedures
Training, competence, and communication
Evidence, records, and reference data governance
Monitoring, internal review, and corrective actions

Who Needs to Comply?

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Organizations that need to implement or reference ISO 21903:2020 for refrigerated hydrocarbon fluids — dynamic measurement — requirements and guidelines for the calibration and installation of flowmeters used for liquefied natural gas (lng) and other refrigerated hydrocarbon fluids, especially teams managing certification readiness, customer assurance, regulated operations, supplier requirements, or cross-functional governance.

Key Requirements

Define Scope and Ownership

Identify the activities, sites, systems, products, services, interested parties, and accountable owners covered by the standard.

Assess Current Practice

Compare existing policies, controls, records, supplier arrangements, data, and governance routines against ISO 21903:2020's expectations.

Implement Controls

Deploy proportionate procedures, operating controls, training, approval gates, supplier requirements, and monitoring routines.

Maintain Evidence

Keep versioned records that link obligations or objectives to decisions, controls, testing, review results, findings, and corrective actions.

Review and Improve

Use internal review, management review, incidents, feedback, audit findings, and changing context to keep the program current.

Penalties & Enforcement

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ISO 21903:2020 is an ISO standard and does not create direct legal penalties by itself. Commercial, contractual, regulatory, accreditation, or customer consequences can still arise when the underlying practices, records, or assurance expectations are not met.