SYDNEY, Australia (10 November 2009)—Luxfer Gas Cylinders has received enquiries about the rupture of a scuba cylinder in New South Wales on 16 August 2009. Various accounts of the incident, including several safety alerts, have been published, some of which may have led readers to believe that Luxfer manufactured the cylinder involved in the incident. This is not the case.
The cylinder that ruptured was manufactured by CIG Gas Cylinders in Australia in 1984. The incident cylinder was made from 6351 aluminium alloy (AA6351), which CIG used to make scuba cylinders in Australia from 1975 through 1990. This alloy is known to be susceptible under certain circumstances to a rare metallurgical phenomenon called sustained-load cracking (SLC). WorkCover New South Wales has identified SLC as a possible contributing factor in the August 2009 incident.
Luxfer Gas Cylinders acquired CIG in 1997. Luxfer did not use 6351 alloy for any cylinders that Luxfer subsequently manufactured in Australia under the name Luxfer Australia. Luxfer used only its proprietary 6061 aluminum alloy—which is not susceptible to sustained-load cracking—for all Luxfer Australia cylinders.
For information concerning the New South Wales incident and proper procedures for safely filling aluminium scuba cylinders, please refer to the WorkCover New South Wales 'aluminium scuba cylinders safety alert' pdf (link below).