Calculator
Oxygen Cylinder Duration Calculator
Estimate oxygen cylinder duration from cylinder factor, pressure, reserve pressure, and flow rate.
Calculator Inputs
Cylinder pressure must be a valid number.
Flow rate must be a valid number.
Cylinder pressure must be greater than reserve pressure.
Legend
Oxygen cylinder legend
The cylinder factor converts usable pressure drop into approximate oxygen volume. Reserve pressure is subtracted because a hospital should not plan to empty a cylinder completely.
Input meaning
- Cylinder factor: liters of gas available per psi for the selected cylinder size.
- Cylinder pressure: current gauge pressure before use.
- Reserve pressure: safety pressure left in the cylinder for changeover, transfer delay, or gauge uncertainty.
- Flow rate: total delivered flow in L/min, including all connected devices if more than one is supplied.
Result interpretation
- Usable oxygen is the estimated volume available above the reserve pressure.
- Estimated duration is a planning estimate; actual duration changes with leaks, regulator behavior, and changes in prescribed flow.
Assumptions
- Flow is constant during the calculation period.
- The selected cylinder factor matches the local cylinder standard.
- The gauge reading and regulator are reasonably accurate.
Biomedical use
- Useful for cylinder changeover planning, patient transfer checks, emergency trolley review, and oxygen manifold contingency planning.
How to identify the required values
Use these examples to choose values from gauges, labels, manuals, datasheets, or service reports.
| Field | Example value | Tip |
|---|---|---|
| Cylinder factor | E cylinder often uses about 0.28 L/psi. | Use the factor printed in local policy or cylinder chart; cylinder names vary by country. |
| Cylinder pressure | A full oxygen cylinder gauge may show around 2,000 psi in some systems. | Read the pressure from the regulator gauge before opening the device to the patient. |
| Reserve pressure | Common planning reserve: 200 psi. | Use the hospital transfer/emergency reserve policy, not zero. |
| Flow rate | Nasal cannula 2 L/min; simple mask often 5-10 L/min. | Enter the actual prescribed or device-set flow; increase it if multiple outlets share the cylinder. |
Input Checklist
Confirm these values before relying on the output for procurement, PM, or service planning.
- Cylinder size/factor
- Cylinder pressure
- Reserve pressure
- Oxygen flow
Safety And Engineering Notes
Use calculator outputs as planning estimates and verify critical systems with calibrated measurement or qualified engineering review.
- Use local cylinder factors and policies.
- Do not use estimates as the only basis for emergency oxygen planning.