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How old are your ali tanks?

Do you still use any aluminium diving cylinders that are more than 23 years old? If so, you should note that the Health & Safety Executive has issued a safety alert about their susceptibility to sustained-load cracking (SLC), so they should be checked out straight away.

The HSE says that the alert has been prompted by catastrophic failures of several cylinders made using the aluminium alloys HE30/AA6082 and AA6351, including one in England last year and others in Indonesia and Australia.

The cylinders were made by Luxfer and Reynolds in the UK, Walter Kidde in the USA and CIG in Australia, between 1963 and 1995.

The cylinders should be used only if they have undergone a thorough visual inspection and eddy-current testing by a competent inspector, says the HSE, otherwise “serious harm” could result.

If uncertain if a cylinder uses these alloys, divers are advised to empty it safely and refrain from using it until the alloy can be identified and it can be inspected and tested.

If the alloy can’t be identified from cylinder markings, or it fails the inspection or test, it should be condemned.

Check for specific alloy-related markings or a manufacture date prior to 1995. The following markings could denote an affected cylinder: HE30, HOAL 1, HOAL 2,  HOAL 3,  HOAL 4, BS5045/3/B, BS5045/3/B/S, AA6351 or, as part of the serial number, P****X or P****P.

On some small cylinders from Luxfer’s Aldridge plant, if the three-digit type number stamped around the base starts with a 1, 3 or 5, the alloy is AA6351.

More here.

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15-Mar-18