SPECIAL FEATURE
Worth the wait
Breakthrough in cylinder safety challenges common perceptions
L
ike all closed metal containers, gas cylinders present an explosion risk if exposed to fire. Fire and Rescue Services (FRS) are aware of this and have safe methods for dealing with cylinders involved in fires. If the contained gas is flammable, or is oxygen, this can considerably increase fire loads. But dissolved acetylene (DA) in particular has distinct properties which require special precautions. The direct heat of a fire may, in extreme circumstances, initiate decomposition of acetylene. As an exothermic (heat creating) reaction, this could cause a DA cylinder to reheat after the fire is extinguished. Until recently, this has meant that safety measures for such incidents have been what is now proven to be excessively precautious, involving water cooling for at least 24 hours and a hazard zone of up to 200m. 44
Now, however, a significant breakthrough has been made where acetylene cylinders in fires are concerned – challenging everything that had previously been accepted about decomposition and the safe close out of hazardous incidents. While it may have been a long time coming, the results of a rigorous and major research project involving up to five stakeholder parties could change this particular approach to safety across the world. Disruption DA is the most flexible oxyfuel gas and is used across multiple welding and metal cutting applications. Put simply, there is no replacement for it and when handled, stored and transported correctly, acetylene is perfectly safe and has been invaluable to industry for over 150 years. From 2003 until recently, and only in the
UK, FRS had operated with considerable precaution for DA cylinders, which involved water cooling them for at least 24 hours, during which a hazard zone of 200m radius was usually maintained throughout. Whilst very safe, this often lead to major disruption which, in turn, prejudiced safety away from the incident. The UK protocol had been at odds with what previously operated safely in the UK prior to 2003 and still operated safely in other countries. In 2006 the British Compressed Gases Association (BCGA) joined senior representatives from the Fire Service, Health and Safety Executive (HSE), Department for Transport (DfT), Department for Communities and Local Government (DCLG), Highways Agency, Police, Network Rail, Transport for London (TFL) and others, to form a National Stakeholder Group (NSG) to work together on the issue. www.gasworld.com/specialfeatures