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 = 1.6 m/sD = 25 mmν = 1.31 × 10⁻⁶ m²/s

Water at 10 °C (ν = 1.31 × 10⁻⁶ m²/s) flows at a mean velocity of 1.6 m/s through a pipe with an inside diameter of 25 mm. Find the Reynolds number Re.

V = 1.6 m/sD = 25 mmν = 1.31 × 10⁻⁶ m²/s
Re =
2.Easy
Q = 4 L/sD = 100 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 100 mm at 4 L/s. Find the Reynolds number Re.

Q = 4 L/sD = 100 mmν = 1.31 × 10⁻⁶ m²/s
Re =
3.Medium
Q = 15 L/sD = 100 mmL = 800 mf = 0.025

Water flows at 15 L/s through a pipe 800 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.

Q = 15 L/sL = 800 mD = 100 mmf = 0.025g = 9.81 m/s²
hf = m
4.Medium
V = 2.5 m/sD = 100 mmL = 100 mf = 0.03

Water flows at a mean velocity of 2.5 m/s through a pipe 100 m long with an inside diameter of 100 mm. Use the Darcy friction factor f = 0.03 and g = 9.81 m/s². Find the friction head loss hf.

V = 2.5 m/sL = 100 mD = 100 mmf = 0.03g = 9.81 m/s²
hf = m
5.Hard
K = 5free outletH = ?L = 100 m, D = 300 mm, f = 0.0254× bend (K = 0.3)

A pipe 100 m long with an inside diameter of 300 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), 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 150 L/s?

Q = 150 L/sL = 100 mD = 300 mmf = 0.025Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 5
H = m
6.Hard
K = 10Δz = 13 mL = 300 m, D = 250 mm, f = 0.024× bend (K = 0.3)

Two open reservoirs are joined by a pipe 300 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.02. The water surface of the upper reservoir is 13 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 = 13 mL = 300 mD = 250 mmf = 0.02Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 10Kexit = 1.0
Q = L/s

Answer key

  1. 1. Re = 30534
  2. 2. Re = 38878
  3. 3. hf = 37.18 m
  4. 4. hf = 9.557 m
  5. 5. H = 3.68 m
  6. 6. Q = 129.4 L/s

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