Pipe Pressure Drop — Darcy–Weisbach (Churchill)
Empowering Process, Mechanical & Chemical Engineers
ΣK — Fittings
Manual + added
–
Use the library to add elbows (90°/45°, LR/SR), tees (through/branch), flanges, valves, entrances/exits, reducers/expansions, strainers. ΣK sums automatically.
Add fitting
Library (typical K)
Fittings list
Tap ✖ to remove
Q — Flow Rate
Volumetric
m³/h
Volume per time. Enter Q or switch to Velocity (V) in “Input Mode”.
D — Pipe ID
Inner Ø
mm
Used with Q or V to compute cross-section area and velocity.
L — Length
Run
m
ε — Roughness
Abs. roughness
mm
z — Elevation
(+rise / −drop)
m
ρ — Density
Fluid mass/vol.
kg/m³
Mass per unit volume of the fluid. Affects ΔP directly (Δp = ρ g H).
μ — Dyn. Viscosity
Flow resistance
mPa·s
Resistance to flow; controls Reynolds number and friction factor.
g — Gravity
Optional
m/s²
Temperature
Affects ρ & μ
°C
Temperature influences density and viscosity. If “Water + Auto” is enabled, ρ & μ update from T.
Velocity–m/s
Flow–m³/h
Reynolds––
Regime––
f (Darcy)––
Head loss (pipe)–m
Head loss (fittings)–m
Static (±z)–m
TDH (H)–m
ΔP total–kPa
ΔP–bar / psi
Ready • Q↔V input • Temp-aware water properties • Enter = Calculate
v1.4 • Churchill (1977) • Darcy–Weisbach • Responsive
