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
Q = 25 L/sD = 200 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 200 mm at 25 L/s. Find the Reynolds number Re.

Q = 25 L/sD = 200 mmν = 1.31 × 10⁻⁶ m²/s
Re =
2.Easy
V = 3 m/sD = 150 mmν = 1.14 × 10⁻⁶ m²/s

Water at 15 °C (ν = 1.14 × 10⁻⁶ m²/s) flows at a mean velocity of 3 m/s through a pipe with an inside diameter of 150 mm. Find the Reynolds number Re.

V = 3 m/sD = 150 mmν = 1.14 × 10⁻⁶ m²/s
Re =
3.Medium
Q = 6 L/sD = 100 mmL = 150 mf = 0.02

Water flows at 6 L/s through a pipe 150 m long with an inside diameter of 100 mm. Use the Darcy friction factor f = 0.02 and g = 9.81 m/s². Find the friction head loss hf.

Q = 6 L/sL = 150 mD = 100 mmf = 0.02g = 9.81 m/s²
hf = m
4.Medium
V = 1.4 m/sD = 50 mmL = 100 mf = 0.022

Water (ρ = 1000 kg/m³) flows at 1.4 m/s through a horizontal pipe, 100 m long, with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.022 and g = 9.81 m/s². Find the pressure drop Δp over the pipe in kPa.

V = 1.4 m/sL = 100 mD = 50 mmf = 0.022ρ = 1000 kg/m³
Δp = kPa
5.Hard
K = 5free outletH = ?L = 300 m, D = 150 mm, f = 0.0154× bend (K = 0.3)

A pipe 300 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), 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 20 L/s?

Q = 20 L/sL = 300 mD = 150 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 5
H = m
6.Hard
K = 2Δz = 19 mL = 300 m, D = 250 mm, f = 0.0153× 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 = 0.015. 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), 3 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 = 19 mL = 300 mD = 250 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 2Kexit = 1.0
Q = L/s

Answer key

  1. 1. Re = 121492
  2. 2. Re = 394737
  3. 3. hf = 0.8924 m
  4. 4. Δp = 43.12 kPa
  5. 5. H = 2.461 m
  6. 6. Q = 200.2 L/s

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