The E marking on a cylinder date indicates requalification is due in five years from that date.

• A. 3 years
• B. 7 years
• C. 5 years
• D. 10 years

Answer: (C)

The date marked with the E on a cylinder shows when the next requalification is due. For this marking, the required interval is five years from that date. So the requalification must be completed five years after the date stamped with the E. The other intervals listed don’t match this specific marking, so five years is the correct interpretation.