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 = 2.75 m/sD = 40 mmρ = 891 kg/m³, μ = 0.29 Pa·s

SAE 30 motor oil (ρ = 891 kg/m³, μ = 0.29 Pa·s) flows at 2.75 m/s through a pipe with an inside diameter of 40 mm. Find the Reynolds number Re.

ρ = 891 kg/m³μ = 0.29 Pa·sV = 2.75 m/sD = 40 mm
Re =
2.Easy
Q = 50 L/sD = 150 mmν = 1.31 × 10⁻⁶ m²/s

Water at 10 °C (ν = 1.31 × 10⁻⁶ m²/s) flows through a pipe with an inside diameter of 150 mm at 50 L/s. Find the Reynolds number Re.

Q = 50 L/sD = 150 mmν = 1.31 × 10⁻⁶ m²/s
Re =
3.Medium
V = 1.6 m/sD = 300 mmL = 200 mf = 0.028

Water (ρ = 1000 kg/m³) flows at 1.6 m/s through a horizontal pipe, 200 m long, with an inside diameter of 300 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 = 1.6 m/sL = 200 mD = 300 mmf = 0.028ρ = 1000 kg/m³
Δp = kPa
4.Medium
Q = 80 L/sD = 300 mmL = 50 mf = 0.03

Water flows at 80 L/s through a pipe 50 m long with an inside diameter of 300 mm. Use the Darcy friction factor f = 0.03 and g = 9.81 m/s². Find the friction head loss hf.

Q = 80 L/sL = 50 mD = 300 mmf = 0.03g = 9.81 m/s²
hf = m
5.Hard
K = 5free outletH = ?L = 150 m, D = 300 mm, f = 0.0184× bend (K = 0.3)

A pipe 150 m long with an inside diameter of 300 mm (Darcy friction factor f = 0.018) 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 = 5). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 100 L/s?

Q = 100 L/sL = 150 mD = 300 mmf = 0.018Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 5
H = m
6.Hard
K = 2free outletH = ?L = 100 m, D = 100 mm, f = 0.0253× bend (K = 0.3)

A pipe 100 m long with an inside diameter of 100 mm (Darcy friction factor f = 0.025) 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), 3 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 15 L/s?

Q = 15 L/sL = 100 mD = 100 mmf = 0.025Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 2
H = m

Answer key

  1. 1. Re = 338
  2. 2. Re = 323980
  3. 3. Δp = 23.89 kPa
  4. 4. hf = 0.3264 m
  5. 5. H = 1.704 m
  6. 6. H = 5.466 m

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