Calculator
Steam Velocity Calculator
Calculate the steam velocity in a pipe based on mass flow rate, steam pressure, and pipe internal diameter. Verify the velocity is within safe operating limits.
Interactive toolUpdated July 2026
Inputs
50mm NB sch40 = ~53mm ID
Results
Steam Velocity
22.3 m/s
Status: Good
Volumetric Flow
49.2 L/s
Specific Volume
0.2 m³/kg
At 10 bar g
Velocity Guidelines
| Velocity Range | Assessment | Action |
|---|---|---|
| Below 15 m/s | Low | Pipe may be oversized — condensation risk |
| 15–35 m/s | Good | Optimal range for saturated steam mains |
| 35–40 m/s | Borderline | Acceptable but monitor — consider larger pipe |
| Above 40 m/s | Too High | Risk of erosion, noise, water hammer — upsize pipe |
Why Velocity Matters
- High velocity causes erosion of pipe internals, especially at bends and fittings
- High velocity picks up condensate from the pipe wall, creating water slugs and water hammer
- Low velocity allows condensate to accumulate, also causing water hammer
- The formula: Velocity = Volumetric Flow / Pipe Cross-Sectional Area