ISO 16923:2016

Overview

ISO 16923:2016 - Natural gas fuelling stations - CNG stations for fuelling vehicles - specifies requirements for the design, construction, operation, inspection and maintenance of compressed natural gas (CNG) fuelling stations for vehicles. It covers stations supplied by pipeline, mobile storage (daughter stations) or LNG vaporization (LCNG per ISO 16924) and applies to gases that meet local gas composition rules or ISO 13686 (including biomethane and upgraded coal-bed methane). The standard includes all equipment downstream of the supply connection point but does not define fuelling nozzles. It applies to slow-fill and fast-fill stations, public or private access, fixed or mobile storage, and multi‑fuel sites - but excludes domestic CNG devices without buffer storage. NOTE: ISO 16923 assumes the incoming gas is odorized; additional safety rules are provided for unodorized gas (Clause 10).

Key Topics and Technical Requirements

ISO 16923 addresses the full lifecycle and key technical elements of CNG stations, including:

• Risk management and site layout guidance (hazardous area classification, separation distances)
• Fuel supply options: pipeline, mobile storage and LNG-derived CNG (LCNG)
• Dryers, compressors and compressor enclosures (instrumentation, crankcase design, ventilation)
• Buffer storage design and mobile (daughter) station operation
• Dispensers and fuelling equipment: hoses, breakaway devices, controls and interlocks
• Pipework and buried piping requirements
• Electrical systems, bonding/grounding, labelling and safe performance after power loss
• Instrumentation & control: gas detection, emergency shutdown systems, ADS logic
• Emergency procedures, testing, commissioning, training and operational documentation
• Inspection and maintenance programs including periodic testing of gas detection Annexes include examples for hazardous zone classification, separation distances, fuelling procedures, emergency instructions and inspection templates.

Practical Applications and Who Uses This Standard

ISO 16923 is essential for:

• Design and engineering teams developing CNG fuelling stations
• Project managers and contractors building stations (fixed or mobile)
• Operators and site owners (public or private) implementing safe operation and maintenance
• Safety engineers and inspectors performing compliance checks and risk assessments
• Equipment manufacturers (compressors, dispensers, detectors, storage systems) aligning products with station requirements Use cases include new CNG station projects, retrofits for LCNG or biomethane supplies, multi-fuel station integration, and development of operational manuals, emergency response plans and inspection schedules.

Related Standards

• ISO 16924 (LCNG - liquefied natural gas to CNG dispensing)
• ISO 13686 (natural gas composition) Normative references within ISO 16923 include: ISO 7-1, ISO 4126-1, ISO 834-1, ISO 8580, ISO 9809-1/-2, ISO 11119-1, among others - useful when specifying components and safety devices.

Keywords: ISO 16923:2016, CNG stations, natural gas fuelling stations, LCNG, buffer storage, compressors, dispensers, gas detection, emergency shutdown, station design, operation, maintenance.