Method
Required circular internal diameter from flow and target velocity only.
Equations
d = 1000 · √4 · V̇π · v
Symbols and units
| Symbol | Quantity | Unit |
|---|---|---|
| Inputs | ||
| V̇ | Flow | m³/s |
| v | Target velocity | m/s |
| Results | ||
| d | Required internal diameter | mm |
Assumptions and limits
- Geometry result only; no nominal size, schedule, material or friction criterion selected.
In practice
- Pick the next nominal size with an internal diameter at least this large, then check friction loss and velocity for the selected size.
Worked example
The input values are the calculator's own verification test, run through the calculator. They show the working; they are not design values.
Inputs
| V̇ | Flow | 0.01 m³/s |
| v | Target velocity | 1 m/s |
Results
| d | Required internal diameter | 112.838 mm |
A preliminary check for engineer review, not an engineering approval. The project calculation to the applicable codes, authority requirements and specification governs.