New cylinders that have not been vacuum purged by the manufacturer and cylinders that have been opened to the atmosphere must be ___________ prior to filling.

• A. Purged of air or moisture
• B. Pressure tested
• C. Painted
• D. Discarded

Answer: (D)

Before filling, cylinders must be clean and free from air and moisture. New cylinders that haven’t been vacuum purged, or cylinders that have been opened to the atmosphere, cannot be trusted to be free of contaminants. If air or moisture is inside, it can lead to moisture-induced corrosion, contamination of the propane, and safety risks during use. Because there’s no reliable way to ensure such cylinders are safe to fill, the practiced safety decision in this context is to discard them rather than attempt to fill. This avoids risking unsafe gas quality or equipment failure.