In CGA pamphlet C-6.1, Standards for Visual Inspection of High Pressure Aluminum Compressed Gas Cylinders, it states in section 4.2 that cuts or digs are acceptable to the following limits:
- Unknown wall thickness, maximum dig = .031″ deep
- Known wall thickness, maximum dig = 15% of minimum design wall thickness.
a) A dig in the sidewall could be:
.320″ (min side wall) x .15% = .048″ deep
b) A dig in the center of the base (the thinnest part of the base) could be:
.515 (min base) x .15% = .077″ deep
c) A dig in the radius and footring at the bottom of the cylinder could be:
= * .128″ (1/8″) deep
* This dig cannot extend up into the sidewall.
- The length of the dig must be less than 6.0″.