Site index
Sitemap
Every page on Pipe Flow Lab, grouped by type. Looking for the machine-readable versions? There's an XML sitemap and an RSS feed of the latest guides.
Calculators
- Pressure Drop Calculator Multi-segment pipe pressure drop with a fitting counter, temperature-adjusted viscosity, and a cost-of-friction estimator. Darcy-Weisbach + Hazen-Williams.
- Hazen-Williams Calculator Hazen-Williams head loss and pressure drop for clean water, with a new-and-aged C-factor library and a live Darcy-Weisbach cross-check on the same inputs.
- Darcy-Weisbach Calculator Darcy-Weisbach pressure drop for any Newtonian fluid — Colebrook–White, Haaland & Swamee-Jain friction factors, plus a temperature-adjusted fluid library.
- Fitting Equivalents Reference Searchable K-factor & equivalent-length reference for elbows, tees, valves and transitions, with a calculator. Source: Crane TP-410, Cameron Hydraulic Data.
- Pump Sizing Calculator Total Dynamic Head, hydraulic kW, motor HP (NEMA), NPSH-available & annual cost of friction. Separate suction/discharge segments, each with a fitting counter.
- Pipe Velocity Check Velocity check — flags sediment and water-hammer risk and recommends the next-up nominal pipe size for a target flow velocity. Uses ASPE safe-velocity bands.
Guides
- Pump affinity laws: speed, diameter, and power How centrifugal pump speed and impeller diameter change flow, head, and power — the three affinity laws with worked examples and VFD savings calculations.
- Reynolds number — laminar vs turbulent flow The Reynolds number predicts laminar vs turbulent pipe flow: Re = ρvD/μ, the 2,000–4,000 transition, the friction-factor link, and worked examples.
- NPSH and pump cavitation explained NPSH explained: NPSHa vs NPSHr, the cavitation mechanism, the vapor-pressure penalty, margin per HI 9.6.1, and how to stop pump cavitation.
- Water hammer — causes, math, prevention Water hammer is a transient pressure spike from sudden valve closure. The Joukowsky equation, critical closure time, column separation, and proven fixes.
- Hazen-Williams vs Darcy-Weisbach Hazen-Williams is empirical, water-only, closed-form. Darcy-Weisbach is physically grounded, fluid-agnostic, and iterative. Here's how to pick the right one.
- Equivalent length 101 — how fittings work A 90° elbow acts like 30 diameters of straight pipe; a globe valve like 340. Where these numbers come from, what they cost, and why calculators ignore them.
- Pipe-material C-factors — sources and aging Hazen-Williams C and Darcy roughness ε for every common pipe material, with new and aged values, sources, and notes on how each ages in service.
- Pump curves — system curve × pump curve Pumps don't deliver a fixed flow. They deliver where their own head-vs-flow curve crosses the system's resistance curve. This guide walks through the visual.
Reference
- Methodology — formulas & sources The formulas, friction-factor correlations, and published references behind every Pipe Flow Lab calculator, with the assumptions and limits of each.
- About Pipe Flow Lab Who builds Pipe Flow Lab, the editorial standard behind the numbers, and why every tool is free with no login and no paywall.