SociÃ©tÃ© Metallurgique de Gerzat (SMG) warns of ruptures in high-pressure cylinders made from aluminium alloy 5283 (AA5283).
Following an investigation into the reported incidents SMG has determined that some AA5283 cylinders may undergo metallurgical changes that require special precautions.
As a result, the French producer of high-quality aluminium alloy cylinders for compressed gases, announces the following safety recommendations for use of SMG high-pressure cylinders manufactured from AA5283:
A. General recommendations:
Service-life limitations: Do not refill AA5283 cylinders older than 25 years, and remove the cylinders from service immediately unless SMG agrees otherwise.
Temperature restrictions: Do not expose AA5283 cylinders to temperatures higher than 80 degrees C in service. If AA5283 cylinders are exposed to temperatures between 70 and 80 degrees C, the cumulative exposure time to those elevated temperatures must not exceed 30 minutes. Any AA5283 cylinder that has been used in a way that does not meet these temperature restrictions must be removed from service immediately.
B. Specific recommendations:
Cylinders used for scuba diving: Remove all AA5283 scuba cylinders from service immediately. The new SMG recommendation reiterates all previous regulatory agency mandates for removal and further recommends removal of all AA5283 scuba cylinders not covered by prior mandates.
Acetylene cylinders: In accordance with the French \\$quot;˜Arrete\\$quot; order (dated 29 December 1995) all AA5283 acetylene cylinders with \\$quot;˜GIP2 mass\\$quot; must be removed from service immediately. For all other AA5283 acetylene cylinders, the suitability of the massing process and other associated heat treatments must be approved by SMG before cylinders can continue being used.
Cylinders used in marine environments: AA5283 cylinders older than 15 years that have been exposed to marine environments must be removed from service immediately. This includes cylinders used aboard ships, on offshore platforms and in similar or more aggressive environments.
Fire extinguisher cylinders: All AA5283 carbon dioxide fire extinguisher cylinders are not subject to the service-life limitations mentioned in paragraph A.
All cylinders subject to the above safety recommendations were manufactured from AA5283 metal supplied by Pechiney, the former owner of SMG. Pechiney sold SMG to Luxfer Group in 2001.