FAQs

• Out of a total population of approximately 1,073,000 Luxfer scuba cylinders made of 6351 alloy, only 1.25% have exhibited SLC. 
• Out of Luxfer’s total 6.1-million population of 6351-alloy cylinders, the SLC rate is slightly less than 0.37%. 
• While we do not have complete statistics on cylinders manufactured by other companies, industry experts estimate that out of a worldwide population of more than 30 million 6351-alloy cylinders, far less than 1% have exhibited SLC.

• Very slowly, as extensive research by Luxfer and outside laboratories has shown. 
• No scientific evidence supports rumors and claims of “fast crack growth.” 
• Cracks typically take eight or more years to grow large enough to cause a cylinder leak. 
• Because SLC growth is so slow, properly trained inspectors have adequate opportunity to detect cracks during the normal requalification process.

• SLC is a metallurgical phenomenon that occasionally develops in cylinders made of 6351 aluminum alloy, as well as in other types of pressure vessels and structural components under stress for sustained periods of time.
• SLC has occurred in cylinders manufactured by various companies, including Luxfer. 
• Cylinders that have been mechanically damaged, over-filled or abused are more susceptible to SLC. 
• SLC is not a manufacturing defect; it is a phenomenon inherent in the metal itself.

All composite cylinders have a 15-year service life in accordance with regulations around the world. In the United States, the service life is set by the U.S. Department of Transportation.