Do you have any comment on the effect of hydro testing on the material of aluminium cylinders?
I am not an expert in metallurgy, so can say very little about material integrity. However, there are specialists who believe that the hydro test procedure may not adequately test aluminium cylinders. The manufacturers cycle many test cylinders to hydro test pressure thousands of times with no apparent damage. I have not heard any expert suggest that the hydro test causes damage to the cylinder. In New Zealand and Australia, cylinders are currently tested every two years, and this may change to every year. In the USA, it is currently every five years and may change to every ten years! What are your thoughts on the wide difference in the period over which cylinders must be hydro-tested? The hydro test alone is not a very good assessment of a cylinder’s condition. Cylinders with obvious cracks and pinholes have passed hydro retest. US rules for retest were written more than 50 years ago, when cylinders were used very differently to how they are used by divers today. Experience in the USA
Do you have any comment on the effect of hydro testing on the material of aluminium cylinders?