01
Formula
Minutes = (gauge − residual) × factor ÷ liters per minute.
Hours = minutes ÷ 60. The oxygen tank duration calculator uses the factor you select: 0.28, 1.56, or 3.14 liters per psi.
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Oxygen cylinder duration calculator
This oxygen cylinder duration calculator estimates minutes from the pressure you can use, a cylinder factor in liters per psi, and the flow in liters per minute. The oxygen tank duration calculator is the same formula. Factors filled in are planning values: E at 0.28, M at 1.56, and H or K at 3.14. This is not a medical device and not a guarantee a welder or a patient will have gas left.
Duration
9.42h
Minutes565
Usable psi1,800
Flow10.00 L/min
Planning estimate from the numbers you enter. Coverage, density, waste and price are assumptions, not a supplier quote or an engineering specification.
How it works
Minutes equal usable psi times the factor, divided by flow.
Usable pressure is the gauge reading minus the residual you plan to leave. An H or K cylinder at 2,000 psi, leaving 200 psi, has 1,800 psi to use. At a factor of 3.14 and a flow of 10 liters per minute, duration is 565 minutes, or 9.42 hours. The factor is liters per psi for that cylinder family. A different maker's cylinder can differ. Confirm the factor stamped or published for the cylinder you have. Welding flow is often quoted in cubic feet per hour. Convert to liters per minute before you type, or the hours will not match the torch. One cubic foot per hour is about 0.47 liters per minute. This page will not make that conversion for you.
02
Example
H or K cylinder, 2,000 psi, 200 psi residual, 10 liters per minute.
Usable pressure is 1,800 psi. Duration is 565 minutes, which is 9.42 hours. Drop the flow and the hours rise in proportion.
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Tips
Leave a residual so the cylinder is not emptied flat.
The 200 psi default is a planning residual, not a rule from a gas supplier. Some users leave more. The duration only counts the pressure above the residual you typed.
04
Equipment
Regulators and welding machines are shop equipment.
Dengaro arranges financing for welding equipment. Cylinder minutes are not a loan amount. Do not use this page as a clinical instruction.
Important questions
Know what to expect.
Are 0.28, 1.56, and 3.14 exact for every tank?+
They are the common planning factors for E, M, and H or K cylinders. The oxygen cylinder duration calculator is only as right as the factor. Use the factor for your cylinder if it differs.
What if my flow is in cubic feet per hour?+
Convert it. Multiply cubic feet per hour by about 0.472 to get liters per minute, then type that. The oxygen tank duration calculator does not have a cubic-foot mode.
Does this include a leak or a purge?+
No. It assumes the flow you typed is steady until the residual. Purge gas and leaks shorten the real time.
Is this medical advice?+
No. It is arithmetic for a cylinder and a flow. A care plan or a welding procedure is a separate document.
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