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 = 1.75 m/sD = 25 mmρ = 850 kg/m³, μ = 0.005 Pa·s

Light fuel oil (ρ = 850 kg/m³, μ = 0.005 Pa·s) flows at 1.75 m/s through a pipe with an inside diameter of 25 mm. Find the Reynolds number Re.

ρ = 850 kg/m³μ = 0.005 Pa·sV = 1.75 m/sD = 25 mm
Re =
2.Easy
V = 0.4 m/sD = 200 mmν = 1.00 × 10⁻⁶ m²/s

Water at 20 °C (ν = 1.00 × 10⁻⁶ m²/s) flows at a mean velocity of 0.4 m/s through a pipe with an inside diameter of 200 mm. Find the Reynolds number Re.

V = 0.4 m/sD = 200 mmν = 1.00 × 10⁻⁶ m²/s
Re =
3.Medium
V = 1.5 m/sD = 300 mmL = 50 mf = 0.015

Water (ρ = 1000 kg/m³) flows at 1.5 m/s through a horizontal pipe, 50 m long, with an inside diameter of 300 mm. Use the Darcy friction factor f = 0.015 and g = 9.81 m/s². Find the pressure drop Δp over the pipe in kPa.

V = 1.5 m/sL = 50 mD = 300 mmf = 0.015ρ = 1000 kg/m³
Δp = kPa
4.Medium
Q = 200 L/sD = 300 mmL = 500 mf = 0.03

Water flows at 200 L/s through a pipe 500 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 = 200 L/sL = 500 mD = 300 mmf = 0.03g = 9.81 m/s²
hf = m
5.Hard
K = 0.2Δz = ?L = 200 m, D = 150 mm, f = 0.0153× bend (K = 0.3)

Two open reservoirs are joined by a pipe 200 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.015. The minor losses are a square-edged entrance (K = 0.5), 3 bends (K = 0.3 each), a valve (K = 0.2) 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 30 L/s?

Q = 30 L/sL = 200 mD = 150 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 0.2Kexit = 1.0
Δz = m
6.Hard
K = 0.2free outletH = ?L = 100 m, D = 150 mm, f = 0.0152× bend (K = 0.3)

A pipe 100 m long with an inside diameter of 150 mm (Darcy friction factor f = 0.015) 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), 2 bends (K = 0.3 each) and a valve (K = 0.2). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 40 L/s?

Q = 40 L/sL = 100 mD = 150 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 0.2
H = m

Answer key

  1. 1. Re = 7438
  2. 2. Re = 80000
  3. 3. Δp = 2.813 kPa
  4. 4. hf = 20.4 m
  5. 5. Δz = 3.32 m
  6. 6. H = 3.212 m

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