Frequently Asked Questions
Saving you time by providing clear, immediate solutions to the most frequently asked cylinder questions.
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Ultrasonic testing (UE) employs a transducer and a membrane to examine a cylinder for wall thickness and internal flaws, whereas hydrostatic testing (hydro) involves using water and air pressure to detect leaks and measure any expansion.
- Any steel cylinder manufactured after 1946 is eligible for ultrasonic examination (UE).
- Aluminum cylinders manufactured after 1990 are eligible for ultrasonic examination (UE).
- A UE test is good for up to 10 years based on the gas.
- Any cylinder can be hydrostatically tested unless it is stamped “ISO 9809-2” and certain cylinders stamped with “ISO 9809-1” indicate that ultrasonic examination is the only approved method. Steel cylinders manufactured in 1945 or earlier can only be tested by hydrostatic testing; however, the requalification is only valid for 5 years—unless the customer holds a Special Permit that authorizes a 10-year interval.
- A hydrostatic test is valid for 5 to 10 years, depending on the age and type of gas the cylinder is intended to contain.
Our turnaround time for re-testing or re-certification of a cylinder is roughly 2-4 weeks.
- We do not re-certify cryogenic cylinders. We repair them to factory standard.
- Our warranty is 2 years for anything we replace or provide.
Yes, we can re-certify composite-wrapped cylinders, provided the cylinder is listed under a Special Permit that we are authorized to service. Our Midwest Cylinder Division must be listed by RIN (Requalifier Identification Number) on the applicable Special Permit. Composite cylinders are not stamped with a test date. Instead, we apply a certification sticker using epoxy.