Overview
EN ISO 13686:2013 - Natural gas: Quality designation defines the parameters required to describe finally processed and, where required, blended natural gas. Rather than prescribing numeric limits, this standard specifies what must be reported (components, properties, trace constituents), the units to use and references to measurement standards. Informative annexes provide examples of typical parameter values and focus on health, safety and interchangeability issues.
Key topics
- Quality parameters: composition (methane, ethane, propane, higher hydrocarbons, inert gases such as N2 and CO2) and relevant trace constituents.
- Gas properties: calorific value, density, relative density, Wobbe index and other derived properties used for combustion and metering.
- Sampling and analysis: guidance on representative sampling and references to measurement standards (for example ISO 6974 series for composition, ISO 6976 for calorific values and Wobbe index, ISO 6326 for sulfur compounds, ISO 10101 for water).
- Units and symbols: standardized symbols, abbreviations and subscripts to ensure consistent reporting across organizations and borders.
- Informative annexes: illustrative material covering national methods and interchangeability calculations, including extracts/guidance from DVGW G 260 (Germany), EN 437 (test gases), AGA index, British Hydrocarbon Equivalence, Weaver index, Delbourg method (France), Spanish measurement protocol and harmonization for cross‑border transport.
Practical applications
- Establishing gas quality specifications for pipeline transmission, LNG revaporization and acceptance into local distribution systems (LDS).
- Supporting commercial contracts and custody transfer by providing a standardized set of descriptors for gas deliveries.
- Informing safety assessments and appliance compatibility checks (combustion characteristics, pollutant formation, corrosion risk).
- Guiding laboratories and testing facilities on which measurement methods and ISO references to use for reporting.
- Aiding regulators and network operators in drafting interoperable quality regulations and cross‑border harmonization of gas property data.
Who uses this standard
- Gas producers, processors and LNG operators
- Transmission and distribution system operators (TSOs / DSOs)
- Gas laboratories and testing service providers
- Appliance and burner manufacturers concerned with combustion/interchangeability
- Regulators, standards bodies and contract drafters involved in gas quality and trade
Related standards (selected)
EN ISO 13686:2013 is an essential reference for anyone specifying, measuring or managing natural gas quality, ensuring consistent descriptors, measurement references and practical guidance for safe and interoperable gas supply.