What does the hydrostatic test date on a cylinder indicate?

What does the hydrostatic test date on a cylinder indicate?

• A. The color code of the cylinder.
• B. The date of the last cylinder purchase.
• C. The date the cylinder last passed the hydrostatic test.
• D. The manufacturing lot number.

Answer: (C)

The hydrostatic test date shows the last time the cylinder was tested and passed a hydrostatic pressure test. In this test, the cylinder is filled with water and pressurized well above its service pressure to check for leaks, deformations, or failure. A successful test places a date on the cylinder and sets the interval before the next test is due, ensuring the cylinder remains safe to use. This date is not the color code, the last purchase date, or the manufacturing lot number.

The hydrostatic test date shows the last time the cylinder was tested and passed a hydrostatic pressure test. In this test, the cylinder is filled with water and pressurized well above its service pressure to check for leaks, deformations, or failure. A successful test places a date on the cylinder and sets the interval before the next test is due, ensuring the cylinder remains safe to use. This date is not the color code, the last purchase date, or the manufacturing lot number.