Which statement is true regarding cylinder filling rules?

• A. Cylinders may be filled at any time if they look clean
• B. Cylinders past the re-qualification date cannot be filled
• C. Cylinders can be filled if they have a recent inspection, regardless of date
• D. Cylinders never require re-qualification

Answer: (B)

The key point is that a cylinder can only be filled if it is within its approved requalification period. Requalification, typically achieved through hydrostatic testing and inspection by an authorized facility, verifies the cylinder’s structural integrity under pressure. Once the requalification date has passed, the cylinder must not be filled until it has been requalified again. This requirement exists regardless of how clean the cylinder looks or whether it had a recent inspection, because appearance and a one-time check do not guarantee that the cylinder has passed the mandatory pressure tests. Cylinders do require requalification at regular intervals to stay in service, so the statement that matches safety rules is that cylinders past the requalification date cannot be filled.