Engineering Calculators
Piping & Hydraulics
Complete piping and hydraulic calculations for liquid lines, fittings, pressure losses, system curves, NPSH, gravity flow, gas flow, Mach number, choked-flow screening, surge, line inventory and operating checks. Multiple input/output units and calculation history are included.
Clickable piping workflow
Piping and Hydraulics Design Flow
Follow the sequence from design basis and line sizing through liquid or gas hydraulics, equipment interfaces, transient checks and final line-design closeout. Each button opens the relevant existing calculator.
Hydraulic reference
Pipe Roughness and Darcy Friction Factor Tables
Use the absolute roughness table to select an initial value for hydraulic calculations. Friction factor is not a fixed material property: it depends on Reynolds number and relative roughness ε/D. The interactive table below calculates the Darcy friction factor for every listed material at the selected Reynolds number and internal diameter.
| Pipe material / condition | Typical ε (mm) | Typical ε (ft) | Relative roughness ε/D | Darcy f | Design note | Action |
|---|
Friction-factor method
- Laminar: for Re < 2,300, the table uses f = 64/Re and roughness has no effect.
- Transitional: Re from 2,300 to 4,000 is flagged as transitional; avoid relying on a single calculated value for final design.
- Turbulent: Re ≥ 4,000 uses the Swamee-Jain explicit approximation to the Colebrook-White relationship.
- Values are typical references, not measured properties. Pipe age, corrosion, scale, lining condition, fabrication, and service fluid can change effective roughness materially.
- For pump sizing, consider an aged/credible design roughness for required head and a new/clean condition for maximum-flow, motor, NPSH, and control-valve checks.