1.1    IGEM/UP/22 is for those organisations involved in the design and operation of Vacuum Insulated Tanks (VIT) for Liquefied Natural Gas (LNG) Service.

1.2    This Standard has been drafted by an Institution of Gas Engineers and Managers (IGEM) Panel, appointed by IGEM’s Liquid Natural Gas Committee, and has been approved by IGEM’s Technical Co-ordinating Committee on behalf of the Council of IGEM. 

1.3    This Standard summarises best practice for the design, installation, operation, inspection, maintenance and decommissioning of VITs for LNG service. It combines well established practices with new advice on aspects of design and construction of such installations. The Standard consolidates best practice and guidance from Legislation, and existing gas industry standards and procedures, with the aim of helping to achieve safe designs, installations and continuing safe operation for installed VITs throughout the lifetime of the asset.

1.4    This Standard is intended primarily for an informed and experienced audience such as gas engineering professionals, architects, mechanical and electrical engineering consultants, building facilities and maintenance managers and the responsible person associated with LNG VITs. It is assumed that readers of this Standard are familiar with and understand the roles specified in the Construction (Design and Management) Regulations (CDM).  

1.5    Compliance with this Standard cannot confer immunity from statutory legal obligations.

1.6    This Standard makes use of the terms “should”, “shall” and “must” when prescribing particular requirements. Notwithstanding clause 1.9

• the term “should” prescribes a requirement which, it is intended, will be complied with unless, after prior consideration, deviation is considered to be acceptable
• the term “shall” prescribes a requirement which, it is intended, will be complied with in full and without deviation
• the term “must” identifies a requirement by law in GB at the time of publication.

Note: The phrase “prior consideration” means that a suitable and sufficient risk assessment will be completed and documented to show that the alternative method delivers the same, or better level of protection
    
Such terms may have different meanings when used in Legislation, or Health and Safety Executive (HSE) Approved Codes of Practice (ACoPs) or Guidance, and reference needs to be made to such statutory Legislation or official Guidance for information on legal obligations.

1.7    The primary responsibility for compliance with legal duties relating to health and safety at work rests with the employer. The fact that certain employees, for example “responsible engineers”, are allowed to exercise their professional judgement does not allow employers to abrogate their primary responsibilities. Employers must:

• have done everything to ensure, so far as is reasonably practicable, that there are no better protective measures that can be taken other than relying on the exercise of professional judgement by “responsible engineers”
• have done everything to ensure, so far as is reasonably practicable, that “responsible engineers” have the skills, training, experience and personal qualities necessary for the proper exercise of professional judgement
• have systems and procedures in place to ensure that the exercise of professional judgement by “responsible engineers” is subject to appropriate monitoring and review
• not require “responsible engineers” to undertake tasks which would necessitate the exercise of professional judgement that is beyond their competence. There should be written procedures defining the extent to which “responsible engineers” can exercise their professional judgement. When “responsible engineers” are asked to undertake tasks that deviate from this, they should refer the matter for higher review.

1.8    It is now widely accepted that the majority of accidents in industry generally are in some measure attributable to human as well as technical factors. People who initiated actions that caused or contributed to accidents might have acted in a more appropriate manner to prevent them.

To assist in the control of risk and proper management of these human factors, due regard is to be taken of HSG48 and HSG65.

1.9    Notwithstanding Sub-Section 1.6, this Standard does not attempt to make the use of any method or specification obligatory against the judgement of the responsible engineer. Where new and better techniques are developed and proved, they are to be adopted without waiting for the modification of this Standard. Amendments to this Standard will be issued when necessary and their publication will be announced in the Journal of IGEM and other publications as appropriate.

1.10    Requests for interpretation of this Standard in relation to matters within their scope, but not precisely covered by the current text, to be either:

• addressed to Technical Services, IGEM, IGEM House, 26 & 28 High Street, Kegworth, Derbyshire, DE74 2DA; or 
• emailed to technical@igem.org.uk.

These will be submitted to the relevant Committee for consideration and advice, but in the context that the final responsibility is that of the engineer concerned. If any advice is given by or on behalf of IGEM, this does not imply acceptance of liability for the consequences and does not relieve the responsible engineer of any of their obligations.

1.11    This Standard was published in March 2026.

2.1    This Standard shall be applied to the design and operations of LNG VITs for vessels in excess of 200 Tonnes and operating above 500 mbar. The Standard shall be applicable for all new installations.

 Note:    BS EN 13645 is applicable to a range of 5 to 200 tonnes with larger vessels to BS EN 1473

2.2    The equipment system boundary shall encompass the vessel, its supporting structure, spillage retention bunds and valving, and include any other valves and fittings required for its own operation such as vessels, gauges, pipework systems and fill valves.

2.3    The following items of plant are considered to be outside of the main VIT equipment system boundary and are therefore outside of the scope of this Standard:

LNG transfer pumps
vaporisers
atmospheric storage tanks (including tanks below 3.5 barg)
design of compressors
conventionally insulated bulk storage, e.g., single wall tanks with polyurethane insulation
buried storage
associated Liquid Nitrogen (LIN) tank and LIN system
product quality and custody transfer measurement
foam suppression and other arrangements for active fire protection.

2.4    This Standard also provides guidance and mandatory requirements to be applied for each stage of the lifecycle of the asset:

conceptual and detailed design
testing
commissioning
operation
maintenance and Inspection
decommissioning and disposal.
Note: MAH/COMAH and planning consideration for multiple vessels are covered in Section 4.