Pipe friction & head loss worksheet with answers

Free printable Pipe friction & head loss worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
V = 0.5 m/sD = 100 mmρ = 850 kg/m³, μ = 0.005 Pa·s

Light fuel oil (ρ = 850 kg/m³, μ = 0.005 Pa·s) flows at 0.5 m/s through a pipe with an inside diameter of 100 mm. Find the Reynolds number Re.

ρ = 850 kg/m³μ = 0.005 Pa·sV = 0.5 m/sD = 100 mm
Re =
2.Easy
Q = 15 L/sD = 75 mmν = 0.801 × 10⁻⁶ m²/s

Water at 30 °C (ν = 0.801 × 10⁻⁶ m²/s) flows through a pipe with an inside diameter of 75 mm at 15 L/s. Find the Reynolds number Re.

Q = 15 L/sD = 75 mmν = 0.801 × 10⁻⁶ m²/s
Re =
3.Medium
Q = 40 L/sD = 300 mmL = 400 mf = 0.02

Water flows at 40 L/s through a pipe 400 m long with an inside diameter of 300 mm. Use the Darcy friction factor f = 0.02 and g = 9.81 m/s². Find the friction head loss hf.

Q = 40 L/sL = 400 mD = 300 mmf = 0.02g = 9.81 m/s²
hf = m
4.Medium
V = 2.9 m/sD = 250 mmL = 1000 mf = 0.028

Water (ρ = 1000 kg/m³) flows at 2.9 m/s through a horizontal pipe, 1000 m long, with an inside diameter of 250 mm. Use the Darcy friction factor f = 0.028 and g = 9.81 m/s². Find the pressure drop Δp over the pipe in kPa.

V = 2.9 m/sL = 1000 mD = 250 mmf = 0.028ρ = 1000 kg/m³
Δp = kPa
5.Hard
K = 2free outletH = ?L = 150 m, D = 200 mm, f = 0.0224× bend (K = 0.3)

A pipe 150 m long with an inside diameter of 200 mm (Darcy friction factor f = 0.022) runs from an open reservoir and discharges as a free jet into the air. The minor losses are a square-edged entrance (K = 0.5), 4 bends (K = 0.3 each) and a valve (K = 2). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 80 L/s?

Q = 80 L/sL = 150 mD = 200 mmf = 0.022Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 2
H = m
6.Hard
K = 2Δz = ?L = 150 m, D = 150 mm, f = 0.023× bend (K = 0.3)

Two open reservoirs are joined by a pipe 150 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.02. The minor losses are a square-edged entrance (K = 0.5), 3 bends (K = 0.3 each), a valve (K = 2) and the exit into the lower reservoir (K = 1.0). Use g = 9.81 m/s². What difference in water level Δz between the reservoirs gives a flow rate of 20 L/s?

Q = 20 L/sL = 150 mD = 150 mmf = 0.02Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 2Kexit = 1.0
Δz = m

Answer key

  1. 1. Re = 8500
  2. 2. Re = 317912
  3. 3. hf = 0.4352 m
  4. 4. Δp = 471 kPa
  5. 5. H = 7.007 m
  6. 6. Δz = 1.593 m

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