Inputs
Example Data Table
| Scenario | Workers | Rate (L/min) | Hours | Safety | Leak % | Reserve % | Approx. O2 (L) |
|---|---|---|---|---|---|---|---|
| Light inspection | 2 | 0.8 | 1.5 | 1.20 | 3 | 10 | ~ 1,073 |
| Moderate repair | 4 | 1.5 | 2.0 | 1.25 | 5 | 10 | ~ 9,450 |
| Heavy effort task | 6 | 2.3 | 3.0 | 1.40 | 8 | 15 | ~ 41,600 |
Formula Used
Allowed O₂ (L) = Base O₂ × (1 + Leakage) × (1 + Reserve)
Cylinders needed = Allowed O₂ ÷ Cylinder O₂
How to Use This Calculator
- Enter the number of workers who will use supplied oxygen.
- Choose an oxygen rate that matches the expected effort level.
- Set the job duration and select a safety factor for uncertainty.
- Add leakage and reserve percentages based on site conditions.
- Enter cylinder water volume, fill pressure, and oxygen purity.
- Press calculate to see total oxygen, flow targets, and cylinders needed.
- Use the download buttons to keep a record with your notes.
Downloads
CSV and PDF files include inputs, results, and notes for documentation.
Why oxygen planning matters on construction sites
Oxygen supply planning protects crews during confined space entry, hot work support, and shutdown maintenance. A clear estimate prevents mid-task cylinder changes, reduces exposure time, and supports permit documentation. The calculator converts crew size, effort-based consumption, and duration into a total oxygen volume with leakage and reserve allowances.
Inputs that drive requirement accuracy
Consumption rate is the most sensitive input. Light activity can sit near 0.8 L/min per person, while strenuous work can exceed 2.0 L/min. Duration should reflect continuous use time, not shift length. Safety factor adds buffer when conditions vary, while leakage and reserve percentages represent regulator losses and contingency supply.
Cylinder sizing for reliable coverage
Cylinder content is estimated using water volume, fill pressure, and purity. Higher purity increases available oxygen, while lower fill pressure reduces it. The calculator reports both an exact cylinder count and a rounded-up integer to support procurement. Use the rounded value for planning and keep one extra cylinder for critical entries.
Example dataset for a typical repair task
Example inputs: Workers 4, rate 1.5 L/min, duration 2.0 hours, safety 1.25, leakage 5%, reserve 10%, purity 99.5%, cylinder 47 L, pressure 200 bar. Example outputs: Total oxygen about 9,450 L, team flow about 78.75 L/min, cylinders needed about 1.02, rounded to 2.
Field use and documentation workflow
Run the calculator during pre-task planning, then capture the CSV or PDF for the permit pack. Update inputs when crew count changes, work intensity increases, or cylinder pressure differs from assumptions. For multi-stage work, calculate each stage separately and sum totals, maintaining the same reserve strategy for the full entry window.
FAQs
1) What oxygen rate should I use for each worker?
Use an effort-based estimate. Light tasks often use 0.5–1.0 L/min, moderate work 1.0–2.0 L/min, and heavy exertion 2.0–3.0 L/min. When unsure, select a higher value and document the assumption.
2) Why include leakage and reserve allowances?
Leakage covers losses from hoses, fittings, and regulator behavior. Reserve is contingency supply for delays, egress, or unexpected demand. Together, they reduce the chance of running short during critical operations.
3) Does cylinder size depend on pressure and purity?
Yes. Higher fill pressure increases stored gas volume, while higher purity increases usable oxygen fraction. The calculator combines both to estimate available oxygen per cylinder and then sizes the required cylinder count.
4) Why does the calculator show rounded cylinders needed?
Field planning uses whole cylinders. Rounding up ensures the estimated total oxygen is fully covered. For high-risk entries, consider adding an additional standby cylinder beyond the rounded requirement.
5) Should I change the safety factor for confined spaces?
Often yes. If conditions are uncertain, access is difficult, or the work scope may expand, increasing the safety factor improves resilience. Apply a consistent factor across similar tasks for comparable planning.
6) Are the mass and m³ outputs required for procurement?
Procurement typically uses cylinders or liters. Mass and cubic meters help with engineering checks, transport planning, and reporting. They also provide a consistent basis for comparing different supply methods.
7) Can I use this for staged work across multiple periods?
Yes. Calculate each stage separately using its duration and intensity, then sum oxygen totals. Keep the same reserve approach, and confirm each stage’s cylinder pressure and purity match your assumptions.