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 = 1.7 m/sD = 75 mmν = 0.801 × 10⁻⁶ m²/s

Water at 30 °C (ν = 0.801 × 10⁻⁶ m²/s) flows at a mean velocity of 1.7 m/s through a pipe with an inside diameter of 75 mm. Find the Reynolds number Re.

V = 1.7 m/sD = 75 mmν = 0.801 × 10⁻⁶ m²/s
Re =
2.Easy
Q = 2 L/sD = 40 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 40 mm at 2 L/s. Find the Reynolds number Re.

Q = 2 L/sD = 40 mmν = 1.31 × 10⁻⁶ m²/s
Re =
3.Medium
V = 2.4 m/sD = 150 mmL = 50 mf = 0.022

Water flows at a mean velocity of 2.4 m/s through a pipe 50 m long with an inside diameter of 150 mm. Use the Darcy friction factor f = 0.022 and g = 9.81 m/s². Find the friction head loss hf.

V = 2.4 m/sL = 50 mD = 150 mmf = 0.022g = 9.81 m/s²
hf = m
4.Medium
V = 2.1 m/sD = 150 mmL = 800 mf = 0.025

Water flows at a mean velocity of 2.1 m/s through a pipe 800 m long with an inside diameter of 150 mm. Use the Darcy friction factor f = 0.025 and g = 9.81 m/s². Find the friction head loss hf.

V = 2.1 m/sL = 800 mD = 150 mmf = 0.025g = 9.81 m/s²
hf = m
5.Hard
K = 5free outletH = ?L = 200 m, D = 150 mm, f = 0.0153× bend (K = 0.3)

A pipe 200 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), 3 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 20 L/s?

Q = 20 L/sL = 200 mD = 150 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 5
H = m
6.Hard
K = 2Δz = 8 mL = 300 m, D = 200 mm, f = 0.0182× bend (K = 0.3)

Two open reservoirs are joined by a pipe 300 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.018. The water surface of the upper reservoir is 8 m above that of the lower one. The minor losses are a square-edged entrance (K = 0.5), 2 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. Find the flow rate Q in L/s.

Δz = 8 mL = 300 mD = 200 mmf = 0.018Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 2Kexit = 1.0
Q = L/s

Answer key

  1. 1. Re = 159176
  2. 2. Re = 48597
  3. 3. hf = 2.153 m
  4. 4. hf = 29.97 m
  5. 5. H = 1.789 m
  6. 6. Q = 70.58 L/s

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