Calculator Inputs
Large screens use three columns, smaller screens collapse automatically.
Example Data Table
These examples show how cylinder size, pressure, and consumption assumptions affect runtime.
| Scenario | Cylinder | Inputs | Estimated Duration |
|---|---|---|---|
| Portable inspection kit | E cylinder | 2000 psi start, 200 psi reserve, 4 L/min, 100% duty, 5% loss | 120.00 minutes |
| Workshop backup bank | H/K cylinder | 2200 psi start, 300 psi reserve, 10 L/min, 100% duty, 2% loss | 584.90 minutes |
| Dual mobile cylinders | 2 × D cylinders | 180 bar start, 20 bar reserve, 6 L/min, 60% duty, 3% loss | 200.27 minutes |
Formula Used
Available Oxygen Volume = (Starting Pressure − Safe Residual Pressure) × Cylinder Factor × Number of Cylinders
Effective Average Flow = Flow Rate × (Duty Cycle ÷ 100) × (1 + Loss Factor ÷ 100)
Duration = Available Oxygen Volume ÷ Effective Average Flow
Standard factors are stored in liters per psi. When bar is selected, the calculator multiplies the psi factor by 14.5038 to obtain liters per bar.
How to Use This Calculator
- Choose the cylinder type or select Custom for a manufacturer-specific factor.
- Pick the pressure unit, then enter starting pressure and safe residual pressure.
- Enter the regulator flow rate in liters per minute.
- Add the number of cylinders available for the calculation.
- Set duty cycle below 100% if flow is intermittent rather than continuous.
- Enter a loss factor to model leaks, purge losses, or connection inefficiency.
- Submit the form to display results above the form, then export as CSV or PDF.
Frequently Asked Questions
1. What does cylinder duration mean?
Cylinder duration is the estimated time a stored oxygen supply can support a chosen flow rate before reaching a protected reserve pressure.
2. Why is safe residual pressure included?
A reserve prevents complete depletion, supports safer changeover, and reflects operational practice where some remaining pressure is kept for contingency.
3. What is a cylinder factor?
The cylinder factor converts pressure drop into usable oxygen volume. Different cylinder sizes store different amounts of gas per pressure unit.
4. When should I use duty cycle?
Use duty cycle when oxygen is not flowing continuously. For example, pulse use, cyclical equipment demand, or periodic process purging.
5. What does the loss factor represent?
Loss factor models extra consumption from leakage, venting, regulator inefficiency, or conservatism added during engineering planning and field checks.
6. Can I calculate multiple cylinders together?
Yes. Increase the cylinder count when cylinders are available as one combined source with equivalent pressure and factor assumptions.
7. Is bar support handled correctly?
Yes. Standard factors are stored in liters per psi, then converted internally to liters per bar whenever bar is selected.
8. Are these results exact for every setup?
No. Results are engineering estimates. Actual runtime depends on regulator behavior, temperature, equipment accuracy, and real operating losses.