Cryogenic Tanks

Static cryogenic tanks must comply with the Pressure Systems Safety Regulations.  They are required to undergo a formal examination by a competent person following a written scheme of examination, as well as routine inspection and maintenance.  Advice is available in BCGA CP 39.

Transportable cryogenic tanks must comply with the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations.  They require periodic inspection and testing.  In Great Britain this must be carried out under the supervision of an Appointed Body, who is an Inspection Body authorised by the National Competent Authority, the Department for Transport (DfT). Information on Inspection Bodies who have been appointed to undertake various functions in connection with the inspection of tanks and / or pressure equipment can be found on the Vehicle Certification Agency (VCA) website.  BCGA GN 48 provides advice on the role of Inspection Bodies.

All examinations, inspections, maintenance and tests must be documented and records have to be kept for the life of the tank.

In service, owners and the users of cryogenic tanks have legal responsibilities and a duty of care to ensure their equipment is maintained and operated safely.  BCGA Leaflet 12 provides advice and guidance on appropriate practice.  The user must carry out routine safety inspections, including daily checks, refer to BCGA Leaflet 11.  When in use a small amount of frosting and ice may be seen.  Small quantities should not be a cause for concern, but the quantity of ice should be routinely monitored.  If ice continues to build-up, de-icing should take place to prevent the ice build-up becoming excessive, advice is available in BCGA Leaflet 21.

A gas supplier will only fill a tank once they have established that it is safe and legal to do so, refer to BCGA CP 48.

Cryogenic tank repair and modification

Any repair or modification to a cryogenic tank shall only be carried out by a competent repairer in accordance with the design codes to which it was manufactured, taking into account current requirements in legislation. Such repairs or modifications shall not affect its integrity or the operation of any protective devices, refer to BCGA CP 39.

All repairs and modifications have to be documented and records have to be kept for the life of the tank.

Cryogenic tank revalidation

Overtime cryogenic tanks may deteriorate due to aging, fatigue, etc.  Cryogenic tanks require a formal periodic assessment to ensure they remain safe for continued use, this is called revalidation. This revalidation period shall be decided by a Competent Person but shall not exceed 20 years. Due to the nature of their service a shorter period for mobile tanks is recommended (refer to BCGA CP 39). When revalidation takes place a report is produced which is to be kept with the tank records for the life of the tank.