Tools / Pipeline sizing
Tool
FLOW VELOCITY · PRESSURE DROP
Pipeline sizing
Change the flow rate and size; the flow speed in the pipe animation is proportional to the real velocity. Click a point on the chart to select a size.
FLUID
PIPE
VALVE BORE
All sizes at this flow rate
| DN | Boremm | Velocitym/s | Δpbar/100 m | Capacitykg/h @ 25 m/s |
|---|---|---|---|---|
| DN15 | 15.8 | 340.0 | 395.278 | 74 |
| DN20 | 20.9 | 193.7 | 90.051 | 129 |
| DN25 | 26.6 | 119.6 | 25.414 | 209 |
| DN32 | 35.0 | 69.1 | 6.070 | 362 |
| DN40 | 40.9 | 50.7 | 2.714 | 493 |
| DN50 | 52.5 | 30.8 | 0.743 | 812 |
| DN65 | 62.7 | 21.6 | 0.298 | 1158 |
| DN80 | 77.9 | 14.0 | 0.098 | 1789 |
| DN100 | 102.3 | 8.1 | 0.025 | 3080 |
| DN125 | 128.2 | 5.2 | 0.008 | 4841 |
| DN150 | 154.1 | 3.6 | 0.003 | 6992 |
| DN200 | 202.7 | 2.1 | 0.001 | 12106 |
| DN250 | 254.5 | 1.3 | 0.000 | 19081 |
| DN300 | 303.2 | 0.9 | 0.000 | 27086 |
How to read it
- Recommended velocity: saturated steam 15–25 m/s, superheated steam 25–40 m/s, water 1–2.5 m/s. High velocity means erosion, noise and water hammer; low velocity means an unnecessarily large pipe.
- Pressure drop is for straight pipe along the line; losses in elbows, valves and fittings are added separately. For steam, the loss should not exceed 10% of the pressure at the start of the line.
- Valve bore: in a reduced-bore valve the flow area is smaller and the velocity increases by (D/d)² (continuity / venturi). The pressure drop across the valve is calculated from its Kv on the product page.
- Steam properties are calculated from pressure for saturated steam and from pressure and temperature for superheated steam; density is assumed constant along the line (valid when the loss is small).
- Accuracy and currency are not guaranteed; use the current edition of the standard for design and purchasing decisions. How the library is compiled →
Sources and assumptions
| ρ | IAPWS-IF97 | ε | 0.045 mm (commercial steel) |
| μ | steam: approx. (0.0403·T + 8.0)·10⁻⁶ Pa·s; water: Vogel equation | f | Swamee–Jain (±1% of Colebrook) |
| d | ASME B36.10 bore | Δp | Darcy–Weisbach |