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Pipe Design Calculator
| Pipe Material | Diameter (mm) | Length (mm) | Flow Rate (L/s) | Fitting Type (one per row) |
Quantity | Pipe Loss (m) | Action |
|---|---|---|---|---|---|---|---|
| Overall Pipe Loss: | 0.00 | ||||||
Custom Fitting Coefficients (Global Overrides)
If provided, these values override the default K values for all pipe segments.
| 90° Miter Elbow: | Short Radius Elbow: | ||
| Long Radius Elbow: | Globe Valve (Open): | ||
| Angle Valve (Open): | Gate Valve (Open): | ||
| Tee (Straight-Through): | Tee (Branch Flow): |
🧠 How This Pipe Design Calculator Works
This tool is designed to help engineers quickly and accurately estimate pipe head losses for a segment of piping that includes flow, material, and fitting characteristics. Whether you’re performing HVAC, plumbing, or mechanical system design, this calculator follows standard industry methods and engineering best practices to support your daily workflows.
🧪 Based on Proven Engineering Standards
This calculator uses the Darcy–Weisbach Equation, a universally accepted formula for determining pressure drop (or head loss) due to friction in a pipe:
Where:
- hf = Head loss due to friction (in meters)
- f = Friction factor (dimensionless)
- L = Pipe length (in meters)
- D = Pipe diameter (in meters)
- V = Average fluid velocity (in m/s)
- g = Gravitational acceleration (9.8 m/s²)
To calculate fff, the calculator determines whether the flow is laminar or turbulent based on the Reynolds number:
- For laminar flow (Re<2300):
For turbulent flow (Re>2300):
The calculator uses the Swamee–Jain equation for friction factor:
🔩 Fitting Losses Based on K-Factor Method
In addition to frictional loss through pipe walls, this tool also calculates minor losses caused by fittings (like elbows, tees, valves). These are computed using the K‑value method:
Where:
- hm = Minor loss head (m)
- K = Loss coefficient for each fitting (dimensionless)
- V = Flow velocity (m/s)
The calculator lets you:
- Select a fitting type (e.g., 90° Miter Elbow, Globe Valve, Tee – Branch)
- Enter the quantity of that fitting
- Override the default K-values globally or per fitting as needed
These K-values are based on published data from industry sources including:
- ASHRAE Fundamentals Handbook
- Crane Technical Paper No. 410
- ASHRAE Duct Fitting Database (adapted to piping)
