How should cylinders that passed the Volumetric Expansion Method be marked?

When cylinders pass the Volumetric Expansion Method, they must be marked with specific information to indicate they have undergone and successfully completed the pressure testing process. The correct option requires the marking to include the Requalification Identification Number (RIN) and the test date. The RIN is a unique identifier used to track the cylinder's requalification status and is crucial for safety and regulatory compliance.

Marking with the test date is equally important as it provides a record of when the cylinder was last tested, allowing users to determine if it is still within the acceptable timeframe for requalification. This detailed marking helps ensure that all cylinders in service are safe and comply with the regulations established for LP gas cylinders.

Other potential markings, while useful, do not provide the critical information that the RIN and test date do for tracking the safety compliance of cylinders.