Visual Eddy Testing

At B & R we offer the newset testing procedures available

Visual Eddy Testing

Cylinders manufactured with aluminum allow 6351-T6 have been shown to be susceptible of sustained load cracking (SLC) in the neck and shoulder area. The Department of Transportation has posted information about DOT 3AL cylinders.

As of January 1, 2007 - The DOT requires a specification or exemption cylinder made of aluminum alloy 6351-T6 and used in and used in self-contained underwater breathing apparatus (SCUBA), self-contained breathing apparatus (SCBA), or oxygen service to be visually inspected and eddy current tested for evidence of  SLC in the neck and shoulder area when the cylinder is pressure tested.

The following manufacturers of aluminum cylinders were affected by the DOT requirements and advisory ruling:

• Walter Kidde DOT-3AL cylinders, of which production ceased in January 1990, are made of alloy 6351-T6.
• Cliff Impact DOT-3AL cylinders were made from alloy 6351-T6 before July 1990, at which time Cliff Impact changed to alloy 6061-T6.
• Catalina Cylinders did not produce any DOT-3AL cylinders from alloy 6351-T6.
• Luxfer DOT-3AL cylinders were made from alloy 6351-T6 from 1960 to 1988, at which time Luxfer changed to alloy 6061-T6. Luxfer has published the dates they changed from alloy 6351-T6 to 6061-T6 for all cylinder models.

Luxfer has published a FAQ on sustained load cracking, and has established a manufacturer's requirement that their cylinders manufactured with alloy 6351-T6 be visually inspected, including an eddy current test, every 2.5 years.

In addition to visual inspection, Carroll offers Visual Eddy testing to determine if a problem exists with the threads around the valve on alloy 6351-T6 cylinders.    Turn around time for Visual Eddy testing is a minimum of 1 business day.