DOT Cylinder Requalification Requirements

A Cylinder Must Be Condemned When:

  1. On visual inspection, it meets a condition for condemnation outlined in CGA pamphlets C-6, C-6.1, C-6.2, and C-6.3, as applicable.
  2. The cylinder leaks through its wall.
  3. Evidence of cracking exists to the extent that the cylinder is likely to be weakened appreciably.
  4. For a DOT specification cylinder (excluding DOT 4E aluminum cylinders) when the permanent expansion exceeds 10% of the total expansion. (12% for DOT 4E cylinders)
  5. For exemption cylinders, refer to current exemption.
  6. For DOT 3HT cylinders, in addition to above, when elastic expansion (EE) exceeds rejection expansion limit (REE).

Marking A Condemned Cylinder

The Retester Shall:

  1. Stamp a series of “X’s” over the DOT specification number and the marked service pressure.


    Stamp “CONDEMNED” on the shoulder, top head or neck using a steel stamp.

  2. Notify the cylinder owner in writing that the cylinder has been condemned.

Department of Transportation Code of Federal Regulations
Title 49 Statute 180.205