Overview
EN ISO 20257-2:2021 - Installation and equipment for liquefied natural gas: Design of floating LNG installations - Part 2: Specific FSRU issues is a CEN-adopted ISO standard published in 2021. It provides specific requirements and guidance for the design, operation and safety of Floating Storage and Regasification Units (FSRUs) described in ISO 20257-1. The standard applies to offshore, near‑shore or docked FSRUs, including both new-built and converted units, and it also addresses requirements for the jetty when an FSRU is moored.
Key topics and technical requirements
EN ISO 20257-2:2021 focuses on FSRU‑specific design, safety and operational considerations. Major technical topics include:
- Basis of design and main process design criteria for FSRUs
- Health, safety and environmental (HSE) requirements, including layout constraints and environmental impacts (water heating/cooling, seawater intake/discharge)
- Mooring and stationkeeping considerations for offshore and docked operations
- Hull design and structural considerations unique to floating LNG installations
- LNG storage specifics (tank pressure management, rollover risk)
- Transfer systems for LNG and send‑out natural gas, including functional design, emergency disconnection and operating envelope
- BOG (boil‑off gas) handling and recovery, compressors and recondenser requirements
- Regasification equipment: LNG pumps, vaporizers, trim heaters, marine fouling and materials selection
- Gas send‑out systems including High Integrity Pressure Protection System (HIPPS) design and send‑out metering
- Requirements for converted FSRUs, jetty interfaces and risk prevention measures
Applications and practical value
This standard is used to:
- Guide detailed engineering and design of FSRU process, mechanical and naval architectures
- Define safety, environmental and operability requirements for LNG regasification offshore or at berth
- Ensure interoperability and consistent technical practices between shipyards, EPC contractors and terminal operators
- Support risk assessments, commissioning, and operation of FSRUs, including emergency procedures and jetty integration
Implementing EN ISO 20257-2 enhances safety, regulatory compliance, and reliability of floating LNG projects while helping manage environmental impacts (e.g., seawater intake/discharge, marine growth control).
Who should use this standard
- LNG plant and FSRU designers and naval architects
- EPC contractors, shipyards and conversion yards
- Offshore installation and mooring engineers
- Terminal and FSRU operators, port authorities and regulators
- HSE, commissioning and operations teams involved in LNG regasification projects
Related standards
- ISO 20257-1 (general design of floating LNG installations) - foundational for Part 2
- Relevant ISO/CEN documents from ISO/TC 67 and CEN/TC 282 for LNG installations
Keywords: EN ISO 20257-2:2021, FSRU, floating LNG, regasification, LNG storage, BOG handling, HIPPS, transfer systems, mooring, jetty requirements.
