Cracking in aluminum gas cylinders: A review of causes and protection measures
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Cracking in a limited number of common portable aluminum gas cylinders has led to leaks and, on occasion, to violent and sometimes fatal failures. This paper describes the failure process and develops a model for crack growth. The model crack growth rates are much higher than those previously determined by small specimen testing. The levels for a threshold stress intensity below which no growth can occur are also introduced.
The inspection procedures and protection strategies for the aluminum gas cylinders are discussed. The system has become both cumbersome and possibly expensive for what it is achieving. There has been no cost benefit assessment of the entire system.
Keywordsaluminum gas cylinders cracking inspections SCUBA
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- 1.R.N. Ibrahim:The Development of a Small K Ic Specimen and Its Application to Sustained Load Cracking in Aluminium Pressure Vessels, Ph.D. thesis, University of New South Wales, School of Mechanical and Industrial Engineering, 1990.Google Scholar
- 2.J.J. Lewandowski, Y.S. Kim, and N.J.H. Holroyd: “Lead-Induced Solid Metal Embrittlement of an Excess Silicon Al-Mg-Si Alloy at Temperatures of −4°C to 80°C,”Metall. Trans. A, 1992,23A, pp. 1679–89.Google Scholar
- 3.S.P. Lynch: “Solid-Metal-Induced Embrittlement of Aluminium Alloys and Other Materials,”Mater. Sci. Eng., 1989,A108, p. 203.Google Scholar
- 4.“Examination of Scott Air-Pak Cylinders,” Failure Analysis Associates, Los Angeles, May 1984.Google Scholar
- 5.R. Poole: “Cylinder Testing,”Prof. Diver J., Winter 1995,1(1), Sydney, Australia.Google Scholar
- 6.“Warning Notice to Gas Filling Stations,” Quality Services Australia, Feb 1998.Google Scholar
- 7.NIOSH, “NIOSH Warns Workers about Explosive Respirator Cylinders,”NIOSH Update, U.S. Dept. of Health and Human Services, National Institute for Occupational Safety and Health, Aug 1993, Morgantown, WV.Google Scholar
- 8.Diver News, U.S. Publication, Sept 1994.Google Scholar
- 9.R. Poole: ibid.Google Scholar
- 10.Luxfer, May 2000, as reported for example on www.visualplus.net/Luxfer%20Australia%20&%20NZ%20Scuba%20Policy%207.17.00.htm.Google Scholar
- 13.J.W.H. Price, R.N. Ibrahim, and D. Ischenko: “Sustained Load Crack Growth Leading to Failure in Aluminium Gas Cylinders in Traffic,”Int. J. Eng. Failure Anal., Dec 1997.Google Scholar
- 15.Retest Cylinder Plant Procedure, CIG Gas Cylinders, Neck Fold Inspection Procedure, Oct 1987, Section L.Google Scholar
- 16.“The Verification, Filling, Testing, Inspection, and Maintenance of Cylinders for the Transport and Storage of Compressed Gasses,” AS 2030.1,Standards Australia, Sydney, 1999 and 2000 amendment.Google Scholar