ISO/TS 18683:2015

TECHNICAL ISO/TS
SPECIFICATION 18683
First edition
2015-01-15
Guidelines for systems and installations
for supply of LNG as fuel to ships
Lignes directrices pour les systèmes et installations de distribution de
gaz naturel liquide comme carburant pour navires
Reference number
©
ISO 2015
© ISO 2015
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 5
4 Bunkering scenarios . 5
5 Properties and behaviour of LNG . 7
5.1 General . 7
5.2 Description and hazards of LNG . 7
5.3 Potential hazardous situations associated with LNG transfer . 8
5.4 Composition of LNG as a bunker fuel . 8
6 Safety . 8
6.1 Objectives. 8
6.2 General safety principles . 8
6.3 Approach . 8
7 Risk assessment . 8
7.1 General . 8
7.2 Qualitative risk assessment .11
7.2.1 Main steps .11
7.2.2 Study basis .11
7.2.3 HAZID .12
7.2.4 Determination of safety zones .15
7.2.5 Determination of security zones .15
7.2.6 Reporting .16
7.3 Quantitative risk assessment .16
7.3.1 Main steps .16
7.3.2 HAZID .16
7.3.3 Establish study basis .16
7.3.4 Quantitative risk assessment .17
7.3.5 Frequency analysis .17
7.3.6 Risk assessment . .17
7.3.7 QRA report .18
8 Functional requirements for LNG bunkering system .18
8.1 General .18
8.2 Design and operation basis .18
8.3 Compatibility between supplier and ship.19
8.4 Prevention of releases of LNG or natural gas to the atmosphere .19
8.5 Safety .19
8.5.1 General.19
8.5.2 Functional requirements to reduce risk of accidental release of LNG and
natural gas .19
8.5.3 Requirements to contain hazardous situations .21
8.5.4 Emergency preparedness .22
9 Requirements to components and systems .22
9.1 General .22
9.2 Available standards for relevant components .22
9.3 Presentation flange and connection .24
10 Training .25
11 Requirements for documentation .26
11.1 General .26
11.2 Compliance statements .26
11.3 Design, fabrication, and commissioning documentation .26
11.4 Operational documentation .26
11.5 Maintenance documentation .27
11.6 Emergency response documentation .27
11.7 Training documentation .27
11.8 Delivery documentation of LNG properties and quantity .28
11.9 Retention of documentation .28
Annex A (normative) Risk acceptance criteria .29
Annex B (informative) Determination of safety zones .31
Annex C (informative) Functional requirements .36
Annex D (informative) Sample ship supplier checklist .38
Annex E (informative) Sample LNG delivery note .44
Annex F (informative) Arrangement and types of presenting connection .45
Annex G (informative) Dry disconnect coupling .46
Bibliography .48
iv © ISO 2015 – All rights reserved

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 the petroleum, petrochemical and natural gas industries.
Introduction
The properties, characteristics, and behaviour of LNG differ significantly from conventional marine
fuels, such as heavy fuel oils and distillate fuels as marine diesel oil (MDO) or marine gas oil (MGO).
For these reasons, it is essential that all LNG bunkering operations are undertaken with diligence and
due attention is paid to prevent leakage of LNG liquid or vapour and to control all sources of ignition.
Therefore, it is necessary that throughout the LNG bunkering chain, each element is carefully designed
and has dedicated safety and operational procedures executed by trained personnel.
It is important that the basic requirements laid down in this Technical Specification are understood and
applied to each operation in order to ensure the safe, secure, and efficient transfer of LNG as a fuel to the ship.
The objective of this Technical Specification is to provide guidance for the planning and design of the
following and thereby ensuring that an LNG fuelled ship can refuel with a high level of safety, integrity,
and reliability regardless of the type of bunkering facility:
— bunkering facility;
— ship/bunkering facility interface;
— procedures for connection and disconnection;
— monitoring procedures during bunkering;
— emergency shutdown interface;
— LNG bunkering process control.
The LNG bunkering interface comprises the area of LNG transfer and includes manifold, valves, safety
and security systems and other equipment, and the personnel involved in the LNG bunkering operations.
This Technical Specification is based on the assumption that the receiving ships and LNG supply
facilities are designed according to the relevant and applicable codes, regulations, and guidelines such
as the International Maritime Organization (IMO), ISO, EN, and NFPA standards and the Society of
International Gas Tankers and Terminal Operators (SIGTTO), the Oil Companies International Marine
Forum (OCIMF), and other recognized documents during LNG bunkering. Relevant publications by these
and other organizations are listed in the Bibliography.
It has to be recognized that in cases where the distance to third parties is too close and the risk exceeds
acceptance criteria, the bunkering location is not to be considered.
It is not necessary that the provisions of this Technical Specification are applied retroactively. It is
recognized that national/local laws and regulations take precedence when they are in conflict with this
Technical Specification.
vi © ISO 2015 – All rights reserved

TECHNICAL SPECIFICATION ISO/TS 18683:2015(E)
Guidelines for systems and installations for supply of LNG
as fuel to ships
1 Scope
This Technical Specification gives guidance on the minimum requirements for the design and operation
of the LNG bunkering facility, including the interface between the LNG supply facilities and receiving
ship as shown in Figure 1.
This Technical Specification provides requirements and recommendations for operator and crew
competency training, for the roles and responsibilities of the ship crew and bunkering personnel during
LNG bunkering operations, and the functional requirements for equipment necessary to ensure safe
LNG bunkering operations of LNG fuelled ships.
This Technical Specification is applicable to bunkering of both seagoing and inland trading vessels. It
covers LNG bunkering from shore or ship LNG supply facilities, as shown in Figure 1 and described in
Clause 4, and addresses all operations required such as inerting, gassing up, cooling down, and loading.
LNG Bunkering Facilities
LNG Supply Facilities ReceivingShip
ESD ESD
Shore-to-ship bunkering
Onshore supply
Truck-to-shipbunkering
Onshore mobile supp ly
Ship-to-ship bunkering
Offshore supply
Figure 1 — Interfaces between bunkering facility and supply/receiving facilities
The use of portable storage tanks such as containers, trailers, or similar to load and store LNG on board
ships to be used as fuel is not part of this Technical Specification.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC Guide 73, Risk management — Vocabulary — Guidelines for use in standards
ISO/TS 16901, Guidance on performing risk assessments in the design of onshore LNG installations including
the ship/shore interface
ISO 17776, Petroleum and natural gas industries — Offshore production installations — Guidelines on tools
and techniques for hazard identification and risk assessment
ISO 31010, Risk management — Guidelines on principles and implementation of risk management
1)
IMO, IGF Code of Safety for Ships using Gases or other Low flashpoint fuels
3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC Guide 73 and the
following apply.
3.1.1
as low as reasonably practical
ALARP
reducing a risk to a level that represents the point, objectively assessed, at which the time, trouble,
difficulty, and cost of further reduction measures become unreasonably disproportionate to the
additional risk reduction obtained
3.1.2
boiling liquid expanding vapour explosion
BLEVE
sudden release of the content of a vessel containing a pressurised flammable liquid followed by a fireball
3.1.3
breakaway coupling
coupling which separates at a predetermined section when required and each separated section contains
a self-closing shut-off valve which seals automatically
Note 1 to entry: A breakaway coupling can be activated automatically by excessive forces or though
mechanical/hydraulic controls.
3.1.4
bunkering
process of transferring fuel to a ship
3.1.5
bunkering installation
piping, process components, instrumentation, and other hardware for the transfer of LNG from the
supplier to the ships manifold
3.1.6
bunkering site
location dedicated for bunkering comprising the bunkering installations, port and jetty, and other
facilities and equipment that should be considered in the planning of bunkering
3.1.7
consequence
outcome of an event
3.1.8
container
portable tank unit
1) The international code of safety for ships using gases or other low-flashpoint fuels is currently under
development.
2 © ISO 2015 – All rights reserved

3.1.9
drip tray
spill containment produced of material that can tolerate cryogenic temperatures
3.1.10
dry disconnect coupling
quick coupling which connects and disconnects with minimum LNG release and each separated section
contains a self-closing shut-off valve, which seals automatically
3.1.11
emergency shut-down
ESD
method that safely and effectively stops the transfer of natural gas and vapour between the receiving
ship and supply facilities
3.1.12
hazard
potential source of harm
3.1.13
hazard identification
HAZID
brainstorming exercise using checklists where the potential hazards in a project are identified and
gathered in a risk register for follow up in the project
3.1.14
impact assessment
assessment of how consequences (fires, explosions, etc.) affect people, structures the environment, etc.
3.1.15
individual risk
probability on an annual basis for an individual to be killed due to accidental events arising from the activity
3.1.16
linkspan
type of drawbridge used mainly in the operation of moving vehicles on and off a RO-RO vessel or ferry
3.1.17
probability
extent to which an event is likely to occur
3.1.18
rapid phase transition
RPT
shock wave forces generated by instantaneous vaporization of LNG upon coming in contact with water
3.1.19
risk
combination of the probability of occurrence of harm and the severity of that harm
3.1.20
risk analysis
systematic use of information to identify sources and to estimate the risk
3.1.21
risk assessment
overall process of risk analysis and risk evaluation
3.1.22
risk contour
two dimensional representation of risk (e.g. IR) on a map
3.1.23
risk evaluation
procedure based on the risk analysis to determine whether the tolerable risk has been achieved
3.1.24
risk matrix
matrix portraying risk as the product of probability and consequence, used as the basis for risk
determination
Note 1 to entry: Considerations for the assessment of probability are shown on the horizontal axis. Considerations
for the assessment of consequence are shown on the vertical axis. Multiple consequence categories are
included addressing impact on people, assets, environment, and reputation. Plotting the intersection of the two
considerations on the matrix provides an estimate of the risk.
3.1.25
risk ranking
outcome of a qualitative risk analysis with a numerical annotation of risk
Note 1 to entry: It allows accident scenarios and their risk to be ranked numerically so that the most severe risks
are evident and can be addressed.
3.1.26
safety
freedom from unacceptable risk
3.1.27
safety zone
area around the bunkering station where only dedicated and essential personnel and activities are
allowed during bunkering
3.1.28
security zone
area around the bunkering facility and ship where ship traffic and other activities are monitored (and
controlled) to mitigate harmful effects
3.1.29
stakeholder
any individual, group, or organization that can affect, be affected by, or perceive itself to be affected by, a risk
3.1.30
tolerable risk
risk which is accepted in a given context based on the current values of society
3.1.31
topping up
final sequence of LNG transfer to ensure correct filling level in receiving tank
3.1.32
water curtain
sprinkler arrangement to protect steel surfaces from direct contact with LNG
3.1.33
white water/mist/fog
mist/fog that will be generated by condensing humidity in air when in contact with cold surfaces
during bunkering
Note 1 to entry: This fog will reduce visibility and can mask minor leaks.
4 © ISO 2015 – All rights reserved

3.2 Abbreviated terms
AIS automatic identification system
ALARP as low as reasonably practical
BLEVE boiling liquid expanding vapour explosion
ERC emergency release coupling
ESD emergency shut-down
ESDV emergency shut-down valve
FMEA failure mode and effects analysis
HAZID hazard identification
HFO heavy fuel oil
HSE health, safety, and environment
IR individual risk
LNG liquefied natural gas
MGO marine gas oil
MSDS material safety data sheets
PPE personal protective equipment
QA/QC quality assurance/quality control
QC/DC quick connect/disconnect coupling
QRA quantitative risk assessment
RPT rapid phase transition
TLV threshold limit values for chemicals
NOTE LNG is defined in EN 1160.
4 Bunkering scenarios
Selection of the bunkering configuration should reflect the following factors:
a) LNG bunkering volumes and transfer rates;
b) simultaneous transfer of other bunker fuels;
c) possible interference with other activities in the port area;
d) transfer equipment;
e) type of receiving ship;
f) possible risk areas according to risk analysis, which shows distance to terminal, gangways, and
linkspan, etc., which is of importance for third-party personnel;
g) met-ocean factors.
Three standard LNG bunkering scenarios have been considered in this Technical Specification (see also
Figure 2). In the base case, it is assumed that bunkering is carried out without simultaneous cargo
operations and without passengers on board and therefore, a QRA might not be required.
In case of bunkering during cargo operations, bunkering with passengers on-board or
embarking/disembarking acceptance is required by all parties (such as authorities, terminal, ship and
bunkering operator, and supplier operator) and shall be supported by a dedicated QRA which shall
address the effects of the simultaneous operations.
NOTE The risk assessment addressing simultaneous operations and passengers as described in 7.3 is to be
carried out as part of the planning and permitting process for the operation.
This QRA are dedicated to bunkering operations for a specific location and shall demonstrate
that the risk is acceptable.
The following scenarios differ in the transfer equipment, the station keeping of both the discharging,
and receiving facilities and storage tanks:
— scenario 1: LNG bunkering via pipeline from onshore supply facilities permanently installed (“shore
to ship LNG bunkering”);
— scenario 2: LNG bunkering from onshore trucks;
— scenario 3: LNG bunkering from offshore supply facilities (“ship to ship LNG bunkering”).
Basically, receiving ships shall be governed by
Basically, LNG storage facilities, trailers, containers, bunker vessels
shall be governed by speciic standards or national/local laws. speciic standards. If necessary, this Technical
If necessary, this Technical Speciication deines additional Speciication deines additional requirements.
requirements.
Figure 2 — Standard bunkering scenarios
6 © ISO 2015 – All rights reserved

5 Properties and behaviour of LNG
5.1 General
The properties, characteristics, and behaviour of LNG differ significantly from conventional marine fuels
such as heavy fuel oils (HFO) and distillate fuels such as marine gas oil (MGO), etc. For these reasons, it
is essential that all LNG bunkering operations are undertaken with diligence and due attention is paid to
prevent leakage of LNG liquid or vapour and that sources of ignition in the vicinity (i.e. inside the safety
zone) of the bunkering operation are strictly controlled. Therefore, it is necessary that throughout
LNG bunkering chain, each element is carefully designed and has dedicated safety operational and
maintenance procedures executed by trained personnel.
5.2 Description and hazards of LNG
Description of LNG is fully covered in ISO 16903 but for the purposes of LNG bunkering, the most
important characteristics compared with marine gas fuel are described in this subclause.
At atmospheric pressure, depending upon composition, LNG boils at approximately ‒160 °C. Released
LNG will form a boiling pool on the ground or on the water where the evaporation rate (and vapour
generation) depends on the heat transfer to the pool.
At this temperature, the vapour is denser than air, becoming lighter than air at approximately ‒110 °C.
Therefore, a release of LNG will initially result in a flammable gas cloud that spreads by gravity in low
lying areas until it warms and slowly becomes buoyant. The cold natural gas can also be mixed with air
and form a flammable cloud. In this case, the flammable cloud will not become buoyant but will drift
with wind and be diluted by atmospheric turbulence and diffusion.
Cold surfaces in the bunkering system can cause mist or fog by condensing humidity in the air that might
mask a release.
LNG for fuel supply may be delivered at elevated pressure and at a temperature exceeding the boiling
point at atmospheric conditions (e.g. at 5 bar and at ‒155 °C). Release of LNG under such conditions will
result in instantaneous flashing and larger vapour release compared to evaporation from liquid pools.
LNG can cause brittle fracture if spilled on unprotected carbon steel. It has a flashpoint lower than any
ambient temperature that can be encountered.
Natural gas has a flammable range between 5 % and 15 % when mixed with air.
Natural gas has a flashpoint of ‒187 °C and a high self-ignition temperature (theoretically, approximately
540 °C while experiments indicate that 600 °C is more realistic). The properties of traditional fuels are
different; MGO (marine gas oil) has a flashpoint in excess of 60 °C and a self-ignition temperature of
300 °C for marine gas oil (MGO) or a gas oil vapour/aerosol air mixture.
The ignition energy of natural gas/air mixtures is 0,25 mJ which is lower than most other hydrocarbons.
Natural gas releases are not easily ignited by hot surfaces that ignite most FO fires in engine room but
low energy sparks represents a higher risk.
Methane has a very high greenhouse gas potential and venting to the atmosphere shall not be part of
normal operations.
The following are hazards associated with LNG:
— fire, deflagration, or confined explosion from ignited natural gas evaporating from spilled LNG;
— vapour dispersion and remote flash fire;
— brittle fracture of the steel structure exposed to LNG spills;
— frostbite from liquid or cold vapour spills;
— asphyxiation from vapour release;
— over-pressure of transfer systems caused by thermal expansion or vaporization of trapped LNG;
NOTE The thermal expansion coefficient of LNG is high.
— possible RPT (rapid phase transition) caused by LNG spilled into water;
— possible BLEVE of a pressurized tanks subjected to a fire.
NOTE This hazard is not applicable to atmospheric LNG tanks, only to pressurized forms of hydrocarbon storage.
5.3 Potential hazardous situations associated with LNG transfer
The planning, design, and operation should focus on preventing release of LNG and vapour and avoiding
occupational accidents related to the handling of equipment. The risk and hazards related to the LNG
bunkering are closely linked to the potential rate of release in accidental situations and factors such as
transfer rates, inventories in hoses and piping, protective systems such as detection systems, ESD, and
spill protection are essential.
5.4 Composition of LNG as a bunker fuel
The specification of the LNG supplied as fuel shall be agreed upon between the supplier and receiver and
documentation shall be supplied.
6 Safety
6.1 Objectives
Safety shall be the primary objective for the planning, design, and operation of facilities for the delivery of
LNG as marine fuel taking into consideration simultaneous operations and the interaction with third parties
The safety of the bunkering operation shall not be compromised by commercial requirements.
6.2 General safety principles
The planning, design, procurement, construction, and operation should be implemented in quality,
health, safety, and environmental management systems.
6.3 Approach
The safety targets for the operation of the bunkering scenarios shall be demonstrated by meeting the
requirements as defined in Clause 8, Clause 9, Clause 10, and Clause 11, and qualified by a risk assessment
as outlined in Clause 7.
7 Risk assessment
7.1 General
The development of a bunkering site and facility shall be conducted with high focus on safety for
personnel and normally comprises the following:
— definition of study basis;
— establishing safety distances for the operation;
— performing risk assessment of the operation;
8 © ISO 2015 – All rights reserved

— verification that design is in accordance with recognized standards and that agreed safeguards
are implemented.
An assessment of risk to personnel and environment shall be carried out as a part of the development of
the bunkering facility.
The risk assessment shall be carried out in agreement with recognized standards, such as ISO 31010,
ISO 17776, and ISO 16901.
The main steps in the risk assessment shall be to
a) identify what can go wrong (hazard identification),
b) assess the effect (consequence and impact assessment),
c) assess the likelihood (frequency assessment), and
d) decide if the risk tolerable, or identify risk reducing measures.
The risk analysis shall be carried out with a team ensuring an objective and independent assessment.
As a minimum, a qualitative risk assessment shall be carried out as outlined in 7.2. This is the minimum
requirement for bunkering installations complying with the defined standard bunkering scenarios in
Clause 4 and meeting all requirements in Clause 8 to Clause 11.
For bunkering installations deviating from the standard bunkering scenarios defined in Clause 4 or not
meeting all requirements, the qualitative risk assessment shall be supplemented by a detailed assessment
of the deviations as agreed with the regulator. Normally, this includes a comprehensive quantitative
risk assessment to demonstrate that the overall acceptance criteria are met and that implemented
safeguards compensate for not meeting all requirements. The requirements for the quantitative risk
assessment are outlined in 7.3. Bunkering with passengers on board shall be supported by a QRA and
also requires acceptance by all parties.
The schematic approach is illustrated in Figure 3.
Deinition of study basis
Qualitative Risk Assessment
Determine Safety distances
Standard scenario?
No simultaneous operation?
No
No passengers.
Redeine study basis
QRA completed?
Yes
Yes
Passengers on board?
Passengers boarding/
Disembarking?
No
Passengers and passenger
No
movements accepted by all
parties?
Yes
No
Simultaneous
operations?
Yes
Simop QRA
Are all requirements No
met?
Yes
Additional assessment aligned
with regulatory requirement.
(normally detailed and
Quantitative risk assessment)
Identify additional
No
Accepted by
safeguards
permitting authority?
Yes
Implement agreed
safeguards
Figure 3 — Schematic approach of risk assessment
10 © ISO 2015 – All rights reserved

7.2 Qualitative risk assessment
7.2.1 Main steps
A qualitative risk assessment for a LNG bunkering site and facility and operation shall, as a minimum,
comprise of the following activities:
a) definition of study basis and familiarization with the design and planned operation of the
bunkering facility;
b) HAZID review with the purpose of identifying hazards and assess the risks using a risk matrix.
The HAZID shall also identify risk reducing measures for all hazards representing medium or high
risks. The HAZID should consider accidental spills and consider/identify technical and operational
safeguards. The HAZID shall also determine maximum credible release scenarios as a basis for the
determination of the safety zones;
c) determination of safety zones and security zones (these may later be revised with reference to QRA);
d) reporting.
The qualitative risk assessment shall consider all possible bunkering configurations reflecting the
variety of ships to be bunkered.
7.2.2 Study basis
The basis for the qualitative risk assessment of the bunkering facility shall, as a minimum, comprise of
the following:
a) description and layout of the bunkering installation;
b) description of other simultaneous activities and stakeholders and third parties in the area;
c) description of all systems, components with regard to function, design, and operational procedures
and relevant operational experience;
d) description of operations and operational limitations;
e) organization of the bunkering activities with clear definitions of roles and responsibilities for the
ship crew and bunkering personnel;
f) identification of authority stakeholders;
g) acceptance criteria for the project aligned with authority requirements, in which the risk matrix
shown in Annex A represents example of minimum requirements with respect to risk to personnel.
Important issues that are not defined in the available documentation shall be recorded as assumptions
(with a description of the rationale) and be reflected in the operational plans.
The risk assessment team shall familiarise itself with the study basis through the following:
— document review, interviews with key personnel;
— by actively involving personnel with key knowledge of the design and operation in the risk workshop
to provide required information.
A summary of the study basis with additional assumptions shall be recorded and incorporated as a part
of the risk assessment report.
7.2.3 HAZID
7.2.3.1 General
The HAZID (hazard identification) is the core of the qualitative risk assessment. The HAZID shall be
carried out as a workshop reviewing the possible hazardous events that can occur based on previous
accident experience and judgment. A well-planned and comprehensive HAZID is the critical and
important basis for the risk assessment process.
The HAZID technique is a
— workshop meeting with a multi-discipline team using a structured brainstorming technique based
on a checklist of potential HSE issues,
— means of identifying, describing, and assessing HSE hazards and threats at the earliest practicable
stage of a development, and
— rapid identification and description process only.
7.2.3.2 HAZID team
The HAZID study is carried out by a team representing different disciplines with knowledge of the
plans for the facility and its operation and familiarity with the HAZID process. The HAZID team shall
involve a facilitator supported by experienced representatives from different disciplines. The following
disciplines shall be represented:
a) LNG operational experience;
b) marine expertise;
c) bunkering experience;
d) local knowledge;
e) other specialist should be available “on call”;
f) familiarity with risk assessment techniques for LNG facilities including assessment of dispersion,
fire, and explosion.
The HAZID team shall be selected to ensure objective and independent assessment.
7.2.3.3 HAZID workshop
7.2.3.3.1 Workshop methodology
The HAZID workshop shall systematically review all elements of the system and all operational
sequences with the following aims.
— Identify potentially hazardous events.
— Assess these events with regard to consequence and likelihood and rank the risks. The process of
risk ranking is normally performed using a risk matrix (see Annex A).
— Identify and assess potential risk-reducing measures.
— Identify hazards and safeguards that need to be followed up later in the project.
— Identify maximum credible accidental release (i.e. release scenarios that shall be the basis for
definition of the safety zones).
— Identify need for PPE for the personnel involved in the operation.
12 © ISO 2015 – All rights reserved

7.2.3.3.2 Hazardous events
The HAZID shall, as a minimum, consider the following hazardous events:
a) LNG releases:
1) failure of QC/DC or ERC equipment;
2) hose or loading arm failure due to the following:
— design flaws;
— wear, tear, and fatigue;
— excessive loads due to dropped objects or collision and impacts from ships or trucks;
— ships mooring failure;
— unplanned movement of the truck;
3) pressure surge in transfer lines;
4) releases from piping systems;
5) incorrectly planned or performed maintenance;
6) incorrect operational procedures including the following:
— cooling down;
— connection;
7) failure to detect releases masked by mist and fog due to cold surfaces;
8) failure to detect releases at low level due to location of gas and leak detectors;
9) over-filling and over-pressurization of ships bunker tanks (e.g. by flashing, incorrect bunker
rate, or bunkering procedure);
10) over-pressure of transfer systems caused by thermal expansion or vaporization of trapped LNG;
11) possible rollover in bunker tanks caused by loading LNG of different densities;
b) ignition sources:
1) electrical hazards;
2) other ignition sources;
3) activities inside the safety zone;
4) gas dispersion beyond the safety zone;
c) release of nitrogen, asphyxiation;
d) events caused by human error.
7.2.3.3.3 Hazardous effects
Hazardous effects following the initial events shall be considered. These shall include the following:
a) fire hazards:
1) structural failure and escalation due to high temperatures;
2) injuries to personnel;
3) damage to equipment;
4) ignition of secondary fires;
5) potential BLEVE of pressurized LNG containment subjected to a fire;
b) possible vapour cloud deflagration/flash fires:
1) damage to equipment and escalation;
2) injury to personnel;
3) damage to fire-fightin
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