A cylinder with an expired requalification date shall NOT be refilled until it is requalified by the methods prescribed in DOT regulations. What must be ensured regarding such a cylinder?

A cylinder with an expired requalification date must adhere to strict safety regulations enforced by the Department of Transportation (DOT). When a requalification date has expired, it indicates that the cylinder has not undergone the required inspections and tests designed to ensure its safety and integrity. This is critical because using an unqualified cylinder poses significant risks, including leaks, ruptures, or explosions, which can have serious consequences for individuals and property.

The correct course of action is that the cylinder shall not be refilled until it has been requalified according to the DOT methods. This ensures that the cylinder has been inspected and deemed safe for continued use in handling propane gas. Compliance with these regulations is essential for maintaining safety standards and protecting users from potential hazards associated with outdated or compromised equipment.

Other options suggest either that the cylinder can be refilled after inspection or may be used if undamaged, both of which conflict with the safety protocols that require requalification specifically before any refilling can take place. Additionally, the notion of an owner requalifying their cylinder is also incorrect, as requalification must be performed by a qualified professional following the outlined DOT standards to ensure that safety is not compromised.