ISO 11982:2025
(Main)Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels — Liquefied Natural Gas (LNG) as marine fuel — Measurement on board LNG bunkering ship
Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels — Liquefied Natural Gas (LNG) as marine fuel — Measurement on board LNG bunkering ship
This document provides requirements and guidance for quantifying liquefied natural gas (LNG) as a marine fuel on board LNG bunkering ships. It is applicable to the measurement of LNG from any source, e.g. gas from conventional reservoirs, shale gas, coalbed methane, at the time of: — ship to ship (STS) transfer to LNG-fuelled ships, — STS transfer between LNG bunkering ships, and — transfer to or from shore tanks or other facilities, irrespective of the type of tanks. This document is also applicable to the quantification of biomethane and synthetic methane from fossil fuels or renewable sources.
Hydrocarbures réfrigérés et combustibles gazeux liquéfiés à base non pétrolière — Utilisation du Gaz Naturel Liquéfié (GNL) comme combustible marin — Mesurage à bord des navires avitailleurs de GNL
General Information
Standards Content (Sample)
International
Standard
ISO 11982
First edition
Refrigerated hydrocarbon and non-
2025-11
petroleum based liquefied gaseous
fuels — Liquefied Natural Gas (LNG)
as marine fuel — Measurement on
board LNG bunkering ship
Hydrocarbures réfrigérés et combustibles gazeux liquéfiés à
base non pétrolière — Utilisation du Gaz Naturel Liquéfié (GNL)
comme combustible marin — Mesurage à bord des navires
avitailleurs de GNL
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 On-board measurement . 4
4.1 Outline .4
4.2 Static measurement .5
4.2.1 General .5
4.2.2 Tank capacity table .5
4.2.3 Custody transfer measurement system (CTMS) .6
4.3 Dynamic measurement .7
4.3.1 General .7
4.3.2 Dynamic measurement equipment performance .7
4.3.3 Calibration . . .7
4.3.4 Measurement .7
5 On-board sampling . 7
6 Analysis . . 8
6.1 General .8
6.2 Online analysis .8
7 Calculation method . 8
7.1 General .8
7.2 Static measurement .9
7.2.1 General .9
7.2.2 Liquid level . . .10
7.2.3 Liquid and vapour temperature .10
7.2.4 Vapour pressure . .10
7.2.5 Trim and list .10
7.3 Dynamic measurement .10
7.4 Energy calculation .10
7.4.1 Liquid energy .10
7.4.2 Vapour energy . 12
7.4.3 Wobbe index .14
7.5 Methane number calculation .14
Annex A (informative) Processing of CTMS data .15
Annex B (informative) Calculation example . 19
Annex C (informative) Treatment of unsupported components .29
Annex D (informative) Example of parameters in a bunker delivery note .30
Annex E (informative) Estimation of the composition of comingled LNG.31
Bibliography .36
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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The procedures used to develop this document and those intended for its further maintenance are described
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of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels and
lubricants from natural or synthetic sources, Subcommittee SC 5, Measurement of refrigerated hydrocarbon
and non-petroleum based liquefied gaseous fuels.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
[23]
Efforts such as the restriction of sulfur content in marine fuel oil introduced by IMO MARPOL ANNEX IV
and growing trends towards decarbonisation have promoted cleaner marine fuel.
Liquefied natural gas (LNG) is one of the most practical marine fuel choices. It is considered cleaner than
conventional fuel oils. The conventional trade volume of LNG transported by one shipment is large, with
a total capacity of 170 000 m at the time of publication of this document. The trade quantity is calculated
according to the method defined by the sales and purchase agreement between the cargo supplier and
receiver.
On the other hand, the trade quantity of LNG as a marine fuel by one shipment can be smaller than the
conventional trade volume of 170 000 m . Furthermore, the LNG containment system of the LNG bunkering
ship is unlike the systems of conventional LNG carriers, especially the pressure in the tanks, which is
relatively higher than that of the conventional carrier type. Tank types, including IMO type C, membrane,
and SPB type, are available.
In addition to the difference in trade quantity and the cargo containment system between LNG bunkering
shipments and conventional shipments, the energy transferred during the operations also differs.
Determining the amount of energy transfer involves calculating not only the quantity but also the quality of
transferred liquid and vapour, as well as the gas used during the transfer operation. This document provides
the data treatment, calculation methods and calculation examples.
v
International Standard ISO 11982:2025(en)
Refrigerated hydrocarbon and non-petroleum based liquefied
gaseous fuels — Liquefied Natural Gas (LNG) as marine fuel —
Measurement on board LNG bunkering ship
1 Scope
This document provides requirements and guidance for quantifying liquefied natural gas (LNG) as a marine
fuel on board LNG bunkering ships.
It is applicable to the measurement of LNG from any source, e.g. gas from conventional reservoirs, shale gas,
coalbed methane, at the time of:
— ship to ship (STS) transfer to LNG-fuelled ships,
— STS transfer between LNG bunkering ships, and
— transfer to or from shore tanks or other facilities, irrespective of the type of tanks.
This document is also applicable to the quantification of biomethane and synthetic methane from fossil fuels
or renewable sources.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of thi
...
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