Check the manufacturing date on the cylinder's shoulder or neck for the expiry
Oxygen cylinders do not have a true "expiry date" but require hydrostatic testing every 5 to 10 years depending on the country and cylinder type. The manufacturing date stamped on the cylinder indicates when the next test is due. Look for a series of numbers and letters, often in a diamond shape, showing the month/year of manufacture and the last test date. If the cylinder has passed its test due date, it must be retested before use.
Where to find the manufacturing and test dates
- Shoulder or neck of the cylinder
- Stamped markings in a diamond or oval shape
- Month/year of manufacture (e.g., "05/15" for May 2015)
- Last hydro test date and inspector's mark
How to read cylinder date stamps
- Locate the stamped markings near the top of the cylinder
- Identify the month (often a number or letter) and year of manufacture
- Find the most recent hydro test date, if stamped
- Check if the test is within the required interval (usually 5-10 years)
Hydro test intervals by region
| Region | Test Interval | Notes |
|---|---|---|
| United States | Every 5 years | Stamped with month/year and inspector symbol |
| Europe | Every 10 years | Stamped with last test date |
| Other countries | Varies (5-10 years) | Check local regulations |
What to do if the cylinder is overdue
If the cylinder's last hydro test date exceeds the required interval, do not use it. Return it to the supplier or a certified testing facility for inspection and retesting before refilling or use.
Common questions about oxygen cylinder testing
- Q: Can I use an oxygen cylinder past its test date? A: No, it must be retested before use.
- Q: Does oxygen expire in the cylinder? A: No, oxygen itself does not expire, but the cylinder must be tested for safety.
- Q: Where can I get a cylinder tested? A: Contact your gas supplier or a certified hydrostatic testing facility.