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 = 2.9 m/sD = 40 mmν = 1.00 × 10⁻⁶ m²/s

Water at 20 °C (ν = 1.00 × 10⁻⁶ m²/s) flows at a mean velocity of 2.9 m/s through a pipe with an inside diameter of 40 mm. Find the Reynolds number Re.

V = 2.9 m/sD = 40 mmν = 1.00 × 10⁻⁶ m²/s
Re =
2.Easy
V = 1.25 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 1.25 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 = 1.25 m/sD = 25 mm
Re =
3.Medium
Q = 8 L/sD = 75 mmL = 1000 mf = 0.022

Water flows at 8 L/s through a pipe 1000 m long with an inside diameter of 75 mm. Use the Darcy friction factor f = 0.022 and g = 9.81 m/s². Find the friction head loss hf.

Q = 8 L/sL = 1000 mD = 75 mmf = 0.022g = 9.81 m/s²
hf = m
4.Medium
V = 1.5 m/sD = 100 mmL = 50 mf = 0.025

Water flows at a mean velocity of 1.5 m/s through a pipe 50 m long with an inside diameter of 100 mm. Use the Darcy friction factor f = 0.025 and g = 9.81 m/s². Find the friction head loss hf.

V = 1.5 m/sL = 50 mD = 100 mmf = 0.025g = 9.81 m/s²
hf = m
5.Hard
K = 10Δz = 19 mL = 100 m, D = 150 mm, f = 0.0254× bend (K = 0.3)

Two open reservoirs are joined by a pipe 100 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.025. The water surface of the upper reservoir is 19 m above that of the lower one. The minor losses are a square-edged entrance (K = 0.5), 4 bends (K = 0.3 each), a valve (K = 10) and the exit into the lower reservoir (K = 1.0). Use g = 9.81 m/s². Find the flow rate Q in L/s.

Δz = 19 mL = 100 mD = 150 mmf = 0.025Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 10Kexit = 1.0
Q = L/s
6.Hard
K = 10free outletH = ?L = 200 m, D = 300 mm, f = 0.0224× bend (K = 0.3)

A pipe 200 m long with an inside diameter of 300 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 = 10). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 75 L/s?

Q = 75 L/sL = 200 mD = 300 mmf = 0.022Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 10
H = m

Answer key

  1. 1. Re = 116000
  2. 2. Re = 5313
  3. 3. hf = 49.02 m
  4. 4. hf = 1.433 m
  5. 5. Q = 62.96 L/s
  6. 6. H = 1.57 m

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