The objective of ISO 20257 is to provide requirements and guidance for the design and operation of floating liquefied natural gas (LNG) installations including those for the liquefaction, storage, vaporisation, transfer and handling of LNG in order to have a safe and environmentally acceptable design and operation of floating LNG installations. ISO 20257 is applicable for the following floating LNG installations: -ð Floating LNG liquefaction installations (plant) FLNG the whole floating installation, between the designated gas import connection boundary limit, and the export connection boundary limit. Feed gas can typically be from gas field, associated gas from oil field or from piped gas from a transportation grid. -ð Floating LNG regasification installations (plant) FSRU- the whole floating installation including storage, LNG transfer facilities (from the shuttle manifold), regasification facilities up to the designated gas export connection boundary limit -ð Floating Storage Unit FSU - the whole floating installation including storage, LNG transfer facilities (from the shuttle/LNG carrier manifold) up to FSU export connection boundary limit see definition of FSU in section 3. ISO 20257 is applicable for offshore, near shore or docked floating LNG installations ISO 20257 includes any jetty in the scope in case of docked floating LNG installations with regards to the mooring. Floating LNG mooring concepts are briefly described in section 6 Floating LNG installations are considered to comprise the following major elements: -ð Hull Structure, also known as Hull; -ð Gas Processing, Vaporization and Liquefaction, also known as Topsides (including Flare); -ð LNG Storage, also known Cargo Containment, Systems and Cargo Handling Systems; -ð Hydrocarbon Transfer, also known as Cargo Transfer Systems (including offloading equipment and systems, if applicable); -ð Mooring Systems, including jetties, fendering (if applicable); -ð Other Systems, including utilities, accommodation, etc. Note to entry 1 : Topsides are not relevant for FSU applications. ISO 20257 is covering both Newbuilt and Converted floating LNG installations. Specific Requirements are addressed in section 19 Listing of potential concepts is not intended to be exhaustive. When a novel concept is proposed, it shall follow the general principle of this standard as far as applicable. Such design should result in a concept with equivalent level of safety and environmental friendliness to those currently considered as standard solutions. In case a part of installation (such as hull, vessel or structure) would already be covered by an international standard (including IMO) , the ISO 20257 will only complement the applicable standard where necessary in order to ensure global safety, stability and integrity of the overall floating LNG installation The text below assumes a Floating LNG installation which is generally designed to meet IMO and Classification Society requirements. This is not intended to preclude use of a Barge solution. It should not therefore be assumed that specific requirements are given either to the shape of the installation or to the need for propulsion or for an installation to fall within one regulatory regime or another. Depending, for example, on whether a barge is located offshore or at shore, how it is transported, whether it stores LNG or not, the level of manning, the regulatory regime imposed on it, it may or may not be subject to exactly the same considerations as a unit designed as a non-propelled ship. Individual consideration will need to be given in light of these issues. These issues may include (not exhaustive list): - Hull structure design - Means of external communications - Safety evacuations and escape arrangements Exclusions This standard is not intended to be applicable to - Onshore LNG storage, liquefaction and/or regasification installations/plants. However, standard is applicable to docked FSRU and/or FLNG installations as mentioned above. - Offshore LNG plants based on non-floating structure (such as Gravity Based Structure principle). - Support onshore based facilities (such as support vessels, tugs, & ) This standard is not specifically intended to design Floating Power Generation facilities. However, relevant parts might be used. This standard is not intended to cover LNG as fuel bunkering applications. For these applications, reference is made to ISO 20519 and to publications by the Society for Gas as a Marine Fuel (SGMF).