High-pressure gas cylinders typically degrade from the inside as well as outside. However, cylinders that cannot be removed or easily reached, have historically undergone safety tests far less rigorous than those for transportable tubes.
This has resulted in significant safety, cost & downtime issues for insurers and end-users, because of the susceptibility of these cylinders to damage and erosion.
Now, the British Standards Institution (BSI) - with input from Chesterfield Special Cylinders - has developed BS 8562, the new standard for the inspection and testing of hard to reach/impossible to remove, gas tubes. This forms the core of Chesterfield Special Cylinders’ Integrity Management service.
Chesterfield Special Cylinders is the only company capable of delivering this strict new testing regime worldwide, with bespoke facilities and equipment, operating globally.
The British Standards Institution (BSI) developed BS 8562 as the new standard for the inspection and testing of high pressure gas tubes that cannot be removed once they have been installed. The Standard was created in response to industry concerns over safety, since previous guidance was far less specific than for re-test methods on transportable tubes. The standard was proposed to BSI by Chesterfield Special Cylinders, which contributed to its development, along with other members of the British Compressed Gases Association, (BCGA) and the Safety Assessment Federation, (SAFed).
BS 8562 is a non-destructive ‘In Situ’ testing standard applicable to HP tubes in locations where their removal would be hazardous or impossible (e.g. offshore oil installations) or where the downtime required to remove the vessel would hinder the safe operation of a plant or service (e.g. power generation, hospitals, advanced research applications and marine installations such as heave compensation systems on semi-submersible drilling rigs).
The new Standard employs non-destructive capabilities, including acoustic emission testing, and provides an equivalent level of re-qualification to accepted and proven national and international standards including BS EN 1968: 2002 and ISO 6406: 2005.
This is set to save industry the huge cost of the tubes’ removal and related downtime as they will now be fully tested in situ.
For further information and advice:
Director of Integrity Management
T. +44 (0)1142 427 500
Icebreaking Emergency Evacuation Vessels (IBEEV)
Caspian Sea, Kazakhstan
AGIP (Offshore EP)
Bulk breathing gas storage and supply system in totally enclosed escape craft
Four rescue ships each housing webs, comprised of sixteen 1700 litre breathing air cylinders operating at 350 bar.
Summary of conditions:
The compact design of the evacuation ships totally precluded the removal of the cylinders for re-testing, other than by cutting into the hull.
The classification body had requested the tests and Chesterfield Special Cylinders liaised with them on the Written Scheme of Examination.
Pre-test visits helped gauge the scope of testing and work to be performed.
BS 8562 requires all surfaces to be inspected and evaluated even though the cylinders are stacked with minimal space in between. Although space was very restricted all of the required equipment - lighting, thread cleaning, video scopes, etc. - was deployed in the cramped conditions.
Quantities of sealing tape and weld spatter was discovered. This could have resulted in a major operational problem if the contaminants had gone into the valves and control mechanisms.
Such occurrences highlight the need for engineers and contractors to be aware of the factors which can compromise cylinder performance and safety.
Cylinders were re-qualified as re-tested to BS 8562 and certification issued.