VALICALC · ENGINEERING WORKFLOW
Pipe sizing and flow check
Move from NPS/DN and schedule to bore, velocity and Darcy pressure loss using a consistent flow and fluid condition.
Start this workflowWhat do I need to know first?
- Material, NPS/DN and schedule or measured bore
- Volume flow and fluid temperature/properties
- Straight length, fitting loss coefficients and roughness
Goal and model boundaries
Check a proposed full pipe bore against flow velocity and friction loss, without confusing nominal and inside diameters.
- The continuity and Darcy checks apply to a full circular pipe with the selected fluid properties.
- Compressible, two-phase, open-channel and non-Newtonian design need appropriate additional models.
Find the actual bore
Select the documented material and schedule.
ID = OD − 2 × wall thickness for the nominal published dimensions.
- Expected output
- Inside diameter for the chosen subset row.
- Next step
- Review any lookup handoff before applying it to the flow tool.
Check flow velocity
Choose velocity mode and enter bore and flow.
v = Q / A, where A = πD²/4.
- Expected output
- Mean velocity; inverse modes can propose a calculated bore.
- Next step
- Use this flow and bore in the pressure-loss check.
Calculate friction and fitting loss
Enter full length, roughness, viscosity, density and total K.
Darcy–Weisbach: Δp = (fL/D + ΣK)ρv²/2.
- Expected output
- Pressure loss, head loss, Reynolds number and friction factor.
- Next step
- Compare against available pressure or continue to the pump system workflow.
Units and context
- A nominal 2 inch pipe is not a 2 inch inside diameter.
- GPM is US gallons/minute; volume-flow conversions must precede the velocity check.
Common mistakes to avoid
- Using outside diameter as bore
- Mixing Darcy and Fanning friction factors
- Omitting fittings or assuming viscosity is independent of temperature