O2 Tank Duration Calculator
Enter tank, flow, and safety values. The form uses three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
| Cylinder | Pressure (psi) | Reserve (psi) | Flow (L/min) | Duty (%) | Leak (%) | Estimated Duration (min) |
|---|---|---|---|---|---|---|
| E | 2000 | 200 | 8 | 100 | 0 | 63.00 |
| D | 1800 | 300 | 4 | 100 | 5 | 57.14 |
| M | 2200 | 500 | 10 | 80 | 3 | 321.84 |
| H / K | 1900 | 400 | 15 | 100 | 2 | 307.84 |
Formula Used
The classic tank duration method estimates remaining usable gas from pressure and cylinder factor. It then divides that usable gas by actual average flow demand.
Reserve pressure protects against running a cylinder too low. Duty cycle handles intermittent demand. Leak allowance adds a simple safety correction for real-world losses.
How to Use This Calculator
- Select a standard cylinder type, or choose a custom factor.
- Enter the current gauge pressure in psi.
- Enter the reserve pressure you want to keep unused.
- Enter the required flow rate in liters per minute.
- Set duty cycle below 100% for intermittent usage.
- Add leak allowance and alarm buffer if needed.
- Optionally enter a target duration for pass or fail checking.
- Press calculate to see results, graph, and export options.
Frequently Asked Questions
1) What does cylinder factor mean?
Cylinder factor converts usable pressure into approximate gas volume. Different tank sizes store different amounts per psi, so the factor changes with cylinder type.
2) Why should I keep reserve pressure?
Reserve pressure prevents full depletion, gives reaction time, and supports safer planning. It also avoids depending on every last psi remaining in the tank.
3) Why is my duration shorter than expected?
Shorter duration usually comes from higher flow, higher reserve, leak allowance, or a duty cycle set near 100%. Check all entered assumptions carefully.
4) Can I use a custom cylinder factor?
Yes. Select the custom option and enter the factor supplied by your equipment data, engineering standard, or manufacturer reference sheet.
5) What does duty cycle change?
Duty cycle adjusts average gas consumption. A 50% duty cycle means the gas effectively flows only half the time, extending estimated duration.
6) What is leak allowance for?
Leak allowance adds a simple percentage to expected demand. It helps model regulator loss, connection leakage, or conservative planning margins.
7) What does the Plotly graph show?
The graph plots estimated duration against flow rate for your entered tank conditions. It helps you see how runtime drops as demand rises.
8) Is this suitable for critical medical decisions?
No. This page is an engineering estimate tool. Always follow equipment manuals, site procedures, and qualified clinical or technical guidance where applicable.