How should cylinders that have passed external visual inspections be marked?

Cylinders that have successfully passed their external visual inspections should be marked with the Retest Identification Number (RIN), the retest date, and the year followed by the letter "E." This marking protocol ensures that the cylinder has been properly inspected and meets safety standards for continued use. Including the RIN allows for easy tracking and documentation of the cylinder's testing history, while the retest date and year inform users of when the next inspection or test is required. The addition of the letter "E" signifies that the cylinder has additional certification regarding its condition after inspection. This standardized marking not only helps maintain safety in handling and using cylinders but also complies with regulatory standards related to cylinder inspections.