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 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 1 m/s through a pipe with an inside diameter of 200 mm. Find the Reynolds number Re.

V = 1 m/sD = 200 mmν = 1.00 × 10⁻⁶ m²/s
Re =
2.Easy
Q = 8 L/sD = 100 mmν = 1.14 × 10⁻⁶ m²/s

Water at 15 °C (ν = 1.14 × 10⁻⁶ m²/s) flows through a pipe with an inside diameter of 100 mm at 8 L/s. Find the Reynolds number Re.

Q = 8 L/sD = 100 mmν = 1.14 × 10⁻⁶ m²/s
Re =
3.Medium
V = 1.9 m/sD = 300 mmL = 400 mf = 0.028

Water flows at a mean velocity of 1.9 m/s through a pipe 400 m long with an inside diameter of 300 mm. Use the Darcy friction factor f = 0.028 and g = 9.81 m/s². Find the friction head loss hf.

V = 1.9 m/sL = 400 mD = 300 mmf = 0.028g = 9.81 m/s²
hf = m
4.Medium
V = 1.2 m/sD = 50 mmL = 1000 mf = 0.03

Water (ρ = 1000 kg/m³) flows at 1.2 m/s through a horizontal pipe, 1000 m long, with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.03 and g = 9.81 m/s². Find the pressure drop Δp over the pipe in kPa.

V = 1.2 m/sL = 1000 mD = 50 mmf = 0.03ρ = 1000 kg/m³
Δp = kPa
5.Hard
K = 10Δz = ?L = 200 m, D = 300 mm, f = 0.0253× bend (K = 0.3)

Two open reservoirs are joined by a pipe 200 m long with an inside diameter of 300 mm and a Darcy friction factor f = 0.025. The minor losses are a square-edged entrance (K = 0.5), 3 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. What difference in water level Δz between the reservoirs gives a flow rate of 200 L/s?

Q = 200 L/sL = 200 mD = 300 mmf = 0.025Kentrance = 0.5Kbend = 0.3 (×3)Kvalve = 10Kexit = 1.0
Δz = m
6.Hard
K = 5free outletH = ?L = 300 m, D = 300 mm, f = 0.0154× bend (K = 0.3)

A pipe 300 m long with an inside diameter of 300 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 75 L/s?

Q = 75 L/sL = 300 mD = 300 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 5
H = m

Answer key

  1. 1. Re = 200000
  2. 2. Re = 89350
  3. 3. hf = 6.869 m
  4. 4. Δp = 432 kPa
  5. 5. Δz = 11.86 m
  6. 6. H = 1.303 m

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