SIST EN ISO 20257-2:2021 PDF

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.