Which items are included in the markings on a SCUBA cylinder?

• A. Manufacturer, Serial Number, Manufacture Date, Service Pressure, Material, and Regulatory Authority
• B. Manufacturer, Serial Number, Service Pressure, and Material
• C. Manufacturer, Serial Number, Manufacture Date, and Regulatory Authority
• D. Manufacturer, Serial Number, Material, and Regulatory Authority

Answer: (A)

Cylinder markings serve to identify the item, track its history, and show it meets safety standards. The manufacturer is listed to indicate who produced the cylinder and that it was made to the required quality. The serial number provides a unique identifier so the cylinder’s service history and any recalls can be tracked. The manufacture date helps determine the cylinder’s age and when it will next require hydrostatic testing or retirement due to wear. The service pressure states the maximum allowable working pressure for that cylinder, which guides safe filling and prevents over-pressurization. The material tells you what the cylinder is made of (steel, aluminum, or composite), which influences handling, durability, and compatibility with testing and maintenance. The regulatory authority stamp confirms the cylinder conforms to the applicable safety standards and has passed required inspections. All six markings together give complete, actionable safety information; missing any one of them could obscure critical details needed for safe operation.