ISO/TR 17177:2015

Petroleum and natural gas industries — Guidelines for the marine interfaces of hybrid LNG terminals

ISO/TR 17177:2015 provides guidance for installations, equipment and operation at the ship to terminal and ship to ship interface for hybrid floating and fixed LNG terminals that might not comply with the description of "Conventional LNG Terminal" included in ISO 28460. ISO/TR 17177:2015 is intended to be read in conjunction with ISO 28460 to ensure the safe and efficient LNG transfer operation at these marine facilities. ISO/TR 17177:2015 also addresses high pressure natural gas (HPNG) at the transfer interface at facilities where liquefaction or regasification is undertaken, but does not describe requirements for the process plant generally forming part of the terminal facility. These guidelines are based around facilities that are currently in operation or under development.

Pétrole et industries du gaz naturel — Lignes directrices pour les interfaces de terminaux hybrides de GNL

General Information

• Status: Published
• Publication Date: 06-Apr-2015
• ICS: 75.200 - Petroleum products and natural gas handling equipment
• Technical Committee: ISO/TC 67/SC 9 - Liquefied natural gas installations and equipment
• Drafting Committee: ISO/TC 67/SC 9/WG 7 - Offshore installations for LNG production or regasification
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 20-Sep-2021

Relations

• Consolidated By: ISO 11819-2:2017 - Acoustics — Measurement of the influence of road surfaces on traffic noise — Part 2: The close-proximity method
• Effective Date: 06-Jun-2022

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 17177
First edition
2015-04-01
Petroleum and natural gas
industries — Guidelines for the marine
interfaces of hybrid LNG terminals
Pétrole et industries du gaz naturel — Lignes directrices pour les
interfaces de terminaux hybrides de GNL
Reference number
ISO/TR 17177:2015(E)
ISO 2015
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ISO/TR 17177:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015

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ISO/TR 17177:2015(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Terms, definitions, and abbreviated terms ............................................................................................................................... 1

2.1 Terms and definitions ....................................................................................................................................................................... 1

2.2 Abbreviated terms ............................................................................................................................................................................... 3

3 Hazards of LNG and high pressure natural gas (HPNG) transfer ........................................................................ 4

3.1 General ........................................................................................................................................................................................................... 4

3.2 Hazards of LNG ....................................................................................................................................................................................... 4

3.3 Hazards of high pressure natural gas .................................................................................................................................. 5

3.4 Potential hazardous situations associated with hybrid LNG terminal operations ....................... 5

4 Siting of facility ....................................................................................................................................................................................................... 6

4.1 General ........................................................................................................................................................................................................... 6

4.2 Metocean conditions .......................................................................................................................................................................... 6

4.3 Geological conditions and hazards ........................................................................................................................................ 7

4.4 Environmental and socio-economic impacts ................................................................................................................ 7

5 Marine transfer systems ............................................................................................................................................................................... 8

5.1 General ........................................................................................................................................................................................................... 8

5.2 Marine loading arms (MLAs) for LNG and HPNG ...................................................................................................... 8

5.2.1 Marine loading arms for LNG ................................................................................................................................ 8

5.2.2 Marine loading arms for high pressure natural gas (HPNG MLA) ........................................ 9

5.3 Marine hose transfer systems .................................................................................................................................................... 9

5.3.1 Hose systems for LNG transfer ............................................................................................................................ 9

5.3.2 Hose systems for HPNG transfer .....................................................................................................................10

6 Marine operations ...........................................................................................................................................................................................10

6.1 General ........................................................................................................................................................................................................10

6.2 Terminal information .....................................................................................................................................................................10

6.3 Marine exclusion zones ................................................................................................................................................................11

6.4 Marine interface ..................................................................................................................................................................................11

6.4.1 General...................................................................................................................................................................................11

6.4.2 Mooring arrangements and fenders ............................................................................................................11

6.4.3 Berthing and mooring aids ..................................................................................................................................12

6.4.4 Manifold arrangements ...........................................................................................................................................12

6.4.5 Electrical isolation .......................................................................................................................................................12

6.4.6 Hose supports and handling ...............................................................................................................................13

7 Data and voice communications .......................................................................................................................................................13

8 Hazard management .....................................................................................................................................................................................13

8.1 General ........................................................................................................................................................................................................13

8.2 Protection of leakage of LNG and HPNG ........................................................................................................................13

8.3 Fire and explosion hazard management ........................................................................................................................14

8.3.1 General...................................................................................................................................................................................14

8.3.2 Firefighting and emergency response ........................................................................................................14

9 Security........................................................................................................................................................................................................................15

10 Access and egress ..............................................................................................................................................................................................15

11 Cargo transfer .......................................................................................................................................................................................................16

11.1 General ........................................................................................................................................................................................................16

11.1.1 Management and communication .................................................................................................................16

11.1.2 Conditions to be fulfilled prior to the transfer of LNG .................................................................16

11.1.3 Conditions to be fulfilled prior to the transfer of HPNG .............................................................16

11.1.4 Cargo transfer operations .....................................................................................................................................16

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ISO/TR 17177:2015(E)

11.1.5 Normal disconnection ..............................................................................................................................................16

11.2 Emergency shut-down and emergency release systems .................................................................................17

11.2.1 General...................................................................................................................................................................................17

11.2.2 Emergency shut-down and emergency release systems for LNG MLA .........................17

11.2.3 Emergency shut-down and emergency release systems for LNG transfer hoses .17

11.2.4 Emergency shut-down and emergency disconnect systems for HPNG MLA ............17

11.2.5 Safety and maintenance of transfer systems ........................................................................................18

12 Custody transfer measurement system .....................................................................................................................................19

13 Provision and training of staff .............................................................................................................................................................19

Annex A (informative) ESD I and ESD II systems — Typical arrangements ..............................................................20

Annex B (informative) Typical configurations ........................................................................................................................................24

Bibliography .............................................................................................................................................................................................................................27

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ISO/TR 17177:2015(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any

patent rights identified during the development of the document will be in the Introduction and/or on

the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers

to Trade (TBT), see the following URL: Foreword — Supplementary information.

The committee responsible for this document is ISO/TC 67, Materials, equipment and offshore structures

for petroleum, petrochemical and natural gas industries.
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ISO/TR 17177:2015(E)
Introduction

The recent expansion of the LNG industry has led to the development of marine LNG facilities and

transfer systems that differ from conventional LNG facility designs. These LNG transfer facilities can

require additional or alternative systems and/or operational procedures to enable their safe operation.

This Technical Report is intended to provide guidance for aspects of these facilities not covered by

current standards and guidelines.
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TECHNICAL REPORT ISO/TR 17177:2015(E)
Petroleum and natural gas industries — Guidelines for the
marine interfaces of hybrid LNG terminals
1 Scope

This Technical Report provides guidance for installations, equipment and operation at the ship to

terminal and ship to ship interface for hybrid floating and fixed LNG terminals that might not comply

with the description of “Conventional LNG Terminal” included in ISO 28460.

This Technical Report is intended to be read in conjunction with ISO 28460 to ensure the safe and

efficient LNG transfer operation at these marine facilities.

This Technical Report also addresses high pressure natural gas (HPNG) at the transfer interface at

facilities where liquefaction or regasification is undertaken, but does not describe requirements for the

process plant generally forming part of the terminal facility.

These guidelines are based around facilities that are currently in operation or under development.

2 Terms, definitions, and abbreviated terms
2.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply:
2.1.1
as low as reasonably practicable
ALARP

reducing a risk to a level that represents the point, objectively assessed, at which the time, trouble,

difficulty, and cost of further reduction becomes unreasonably disproportionate to the additional risk

reduction obtained
2.1.2
conventional onshore LNG terminal

LNG export or receiving terminal that is located on-shore and that has a marine transfer facility for the

loading or unloading of LNG carriers in a harbour or other sheltered coastal location

Note 1 to entry: A conventional onshore LNG terminal typically includes marine transfer facility comprising a

jetty equipped with loading arms or similar to enable the transfer of LNG between ship and shore.

2.1.3
double bank
to moor two vessels moored alongside each other at a terminal

Note 1 to entry: An example of double banking as part of a hybrid LNG terminal is where an LNGC moors and

transfers LNG alongside an FSRU or FSU.
2.1.4
emergency release coupling
ERC

device to provide a means of quick release of LNG transfer system when such action is required only as

an emergency measure
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ISO/TR 17177:2015(E)
2.1.5
emergency release system
ERS

system that provides a positive means of quick release of LNG transfer systems and safe isolation

between ship and terminal or between units, following a predefined procedure including an emergency

shut-down (ESD)

Note 1 to entry: The operation of the emergency release system can be referred to as an “ESD II”.

2.1.6
emergency disconnect system
EDS

system that provides a positive means of quick release of HPNG transfer systems and safe isolation

between terminal units or between terminal and ship, following a predefined procedure including an

emergency shut-down (ESD)
2.1.7
emergency shut-down
ESD

method that safely and effectively stops the transfer of LNG or vapour or HPNG between terminal units

or between terminal unit and LNGC

Note 1 to entry: The operation of this system can be referred to as an “ESD I”. Ship/shore ESD systems should not

be confused with other emergency shut-down systems within the terminal or on board ship.

2.1.8
emergency disconnection coupler
EDC

coupler system that when adopted in HPNG transfer systems as part of EDS has combined routine

maintenance and operation connection functionality and emergency disconnection functionality

2.1.9
floating storage and regasification unit
FSRU

floating unit for storage and regasification of LNG and for sending out HPNG and moored for prolonged

periods as part of a hybrid LNG terminal

Note 1 to entry: FSRUs are often but not exclusively classified as sea-going vessels and can be purpose-built or be

converted from a LNGC. Although designed to be moored long term as part of a terminal, FSRUs frequently have

the capability to depart for periodic maintenance or in case of extreme weather.
2.1.10
floating storage unit
FSU

floating unit for storage of LNG and moored for prolonged periods as part of a hybrid LNG terminal

2.1.11
hybrid LNG terminal

LNG export or receiving terminal that is not wholly located onshore and has a marine transfer facility

for the loading or unloading of LNG carriers and for transfer of HPNG to shore

Note 1 to entry: A hybrid LNG terminal can be located in a protected harbour, in a naturally sheltered coastal or

near shore location, or in an unprotected near shore or offshore environment. The marine transfer facilities for

hybrid LNG terminals can include fixed units such as jetties, platforms, and mooring structures. Marine transfer

facilities can also include floating units such as FSRUs, FSUs, and LNGRVs. Transfer of LNG and/or HPNG can take

place at a number of interfaces between fixed and floating units according to the terminal configuration.

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ISO/TR 17177:2015(E)
2.1.12
liquefied natural gas regasification vessel
LNGRV

A sea-going vessel for storage and regasification of LNG and for sending out HPNG and moored for periods as

part of a hybrid LNG terminal and also capable of operating as an LNGC supplying the hybrid LNG terminal

2.1.13
operating basis earthquake
OBE

maximum earthquake for which no damage is sustained and restart and safe operation can continue

2.1.14
safe shutdown earthquake
SSE

maximum earthquake event for which the essential terminal fail-safe functions and mechanisms are

designed to be preserved but for which permanent damage can be expected provided that there is no

loss of overall integrity and containment
2.1.15
rapid phase transition
RPT
explosive change in phase of liquid to vapour
Note 1 to entry: RPT can occur when LNG and water come into contact.
2.1.16
rollover

sudden mixing of two layers of LNG of different densities in a tank, resulting in massive vapour generation

2.1.17
spool piece

short length of pipe with flanges for matching the ship’s manifold flange to the transfer system

presentation flange

Note 1 to entry: Sometimes, reducer spool pieces are used to connect different diameters.

2.1.18
unit

discrete part of a hybrid LNG terminal which can be a fixed or floating structure

Note 1 to entry: Examples of a unit include FSRU, LNGRV, FSU or fixed platform.
2.2 Abbreviated terms
BOG Boil off gas
CDI Chemical Distribution Institute
CTMS Custody transfer measurement system
EERP Evacuation, escape, and rescue plan
EDC Emergency disconnect coupler (HPNG)
EDS Emergency disconnect system (HPNG)
ERC Emergency release coupling (LNG)
ERS Emergency release system (LNG)
ERM Emergency response manual
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ISO/TR 17177:2015(E)
ESD Emergency shut-down
FES Fire and explosion strategy
FSRU Floating storage and regasification unit
FSU Floating storage unit
GBS Gravity based structures
GIIGNL International Group of Natural Gas Importers
HPNG High pressure natural gas
ICS International Chamber of Shipping
IMO International Maritime Organization
ISGOTT International Safety Guide for Oil Tankers and Terminals
LNG Liquefied natural gas
LNGC Liquefied natural gas carrier
LNGRV Liquefied natural gas regasification vessel
MLA Marine loading arms
OBE Operating basis earthquake
OCIMF Oil Companies International Marine Forum
QC/DC Quick connect/disconnect coupler
RPT Rapid phase transition
SIGTTO International Society of Gas Tanker and Terminal Operators
SSE Safe shutdown earthquake
TOM Terminal operating manual
3 Hazards of LNG and high pressure natural gas (HPNG) transfer
3.1 General

The transfer of LNG and HPNG at marine interfaces for hybrid LNG terminal operations results in a

number of potential hazards and hazardous situations in respect of
— properties of LNG and HPNG, and
— the method and conditions of transfer.
Hazard management should be as described in Clause 8.
3.2 Hazards of LNG

Reference should be made to ISO 16903 for guidance on the characteristics of LNG influencing design

and material selection, including the general hazards of handling LNG.
1) To be published.
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Potential hazards arising from the transfer of LNG for hybrid LNG terminals should be subject to risk

assessment taking into account the following:

— cryogenic temperatures, which can cause cold injury to people (frostbite), and also brittle fracture

to non-cryogenic materials such as carbon steel;

— pool fire, flash fire, explosion, or asphyxiation from leaks or spillage of LNG;

— surge pressure in LNG transfer systems;

— overpressure resulting in shock waves, caused by rapid phase transition (RPT) of LNG interacting

with water;
— overpressure due to expansion or vaporization of trapped LNG;

— mechanical damage due to thermal stresses caused by uncontrolled cool-down of piping and

transfer systems;
— rollover.
3.3 Hazards of high pressure natural gas

The potential hazards arising from the transfer of HPNG for hybrid floating and offshore LNG terminals

should be subject to risk assessment taking into account the following:
— jet fire, flash fire, or confined vapour cloud explosion;
— asphyxiation;
— stored energy in high pressures systems;
— high noise level from release of HPNG;
— temperature drop caused by the release of HPNG (Joule-Thomson effect);

— mechanical damage due to vibration from high gas velocities in piping and transfer systems.

NOTE The flammability, explosion, and asphyxiation hazards of HPNG are similar to natural gas (NG), but

the pressures used to transfer and export the HPNG result in very significant additional hazards due to the

velocity and momentum of jet releases and also due to the effects of sudden release of stored energy from a highly

pressurized system. High pressure gas release can entrain air, which if ignited, will result in a jet fire.

3.4 Potential hazardous situations associated with hybrid LNG terminal operations

In addition to the hazardous situations for conventional onshore LNG terminals set out in ISO 28460:2010,

Clause 5, the following potentially hazardous situations should be considered for operational and

contingency planning for hybrid terminals:
— LNG and HPNG transfer operations in close proximity to process equipment;
— simultaneous operations;
— venting and flaring;
— sloshing effects in partially loaded floating storage facilities;
— boil off gas (BOG) management and tank pressure control;

— flange and valve leaks for HPNG transfer systems including any failure or spurious release of the

emergency disconnection system (EDS), if fitted, on the HPNG transfer system;

— relative motions at interfaces as a result of the terminal configuration (e.g. double banking, tandem,

weather-vaning at turret or yoke mooring) and the resulting mechanical stresses and fatigue;

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ISO/TR 17177:2015(E)
— metocean conditions and seismic events including:
— earthquake;
— tsunami;
— icebergs;
— extreme weather events such as tropical cyclones, tornadoes or squalls.

NOTE 1 HPNG gas transfer arms between FSRUs and fixed platforms have at some locations been fitted with

emergency disconnection system (EDS), which provide an automated function similar to that of an emergency

release coupling (ERC) for LNG transfer arms. Unlike the LNG ERC, HPNG EDS systems have typically combined

ERS and QC/DC.

NOTE 2 The motion of floating units incorporating LNG storage can be influenced by the amount of LNG inventory.

NOTE 3 Floating regasification and storage units (FSRUs) may be configured either as permanently moored

facilities, or alternatively, the FSRU can have the capability to depart for LNG supply, trading purposes, or to

depart in advance of extreme metocean conditions.
4 Siting of facility

NOTE The siting considerations for conventional onshore LNG terminals listed in ISO 28460 ought to be

taken into consideration, where applicable.
4.1 General

Site selection for the facility should be based upon a study in accordance with LNG industry best practice.

This study should include a risk assessment undertaken by a multi-discipline team with regard to

identifying and mitigating risks to acceptable levels.

The multi-discipline team should include, as a minimum, expertise and experience of the following:

— marine and port operations;
— LNG carrier and terminal operations;
— metocean conditions;
— design and engineering of marine terminal infrastructure;
— risk assessment and hazard management.
4.2 Metocean conditions

Design and operation of the facility should take into account the environmental conditions at the site.

As a minimum, the following metocean parameters should be taken into consideration:

— wave heights, periods and directions;
— tsunamis;
— current speed and direction throughout the water column;

— wind speed and directions including incidence of tropical storms and local squalls;

— sea ice, icebergs, snow, and ice accretion;
— water level including tidal variations;
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— water temperature and quality;
— air temperature and humidity.

Environmental operating limits should be established for each operation including for approach of

LNGC, berthing, mooring, transfer of LNG and/or HPNG, unberthing and departure. Where the terminal

includes an FSRU or other floating unit, environmental operating limits should also be established for

the FSRU to remain at the facility.

If the FSRU is not capable of remaining safety moored under conditions likely to occur during the

operational life of the terminal, contingency plans and procedures should be established in order that

the FSRU can safely depart in advance of forecast weather conditions that exceed pre-determined limits.

Potential weather downtime for transfer of LNG and/or HPNG should be assessed against operational

requirements and long term observed metocean data or hindcast data for the location.

NOTE 1 Metocean parameters appropriate to design, construction, and maintenance of fixed structures are

normally defined for a range of design situations with performance requirements appropriate to the probability

of occurrence of the parameter or joint probability of combinations of a number of parameters.

NOTE 2 BS 6349–1-1 provides guidance on planning of coastal maritime infrastructure for ships, including

recommendations on environmental data gathering, and incorporation of operational and safety considerations

into design, including the requirements for consultation with operatio
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