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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
V = 2.5 m/sD = 100 mmν = 1.14 × 10⁻⁶ m²/s

Water at 15 °C (ν = 1.14 × 10⁻⁶ m²/s) flows at a mean velocity of 2.5 m/s through a pipe with an inside diameter of 100 mm. Find the Reynolds number Re.

V = 2.5 m/sD = 100 mmν = 1.14 × 10⁻⁶ m²/s
Re =
2.Easy
V = 0.75 m/sD = 25 mmρ = 891 kg/m³, μ = 0.29 Pa·s

SAE 30 motor oil (ρ = 891 kg/m³, μ = 0.29 Pa·s) flows at 0.75 m/s through a pipe with an inside diameter of 25 mm. Find the Reynolds number Re.

ρ = 891 kg/m³μ = 0.29 Pa·sV = 0.75 m/sD = 25 mm
Re =
3.Medium
V = 1.2 m/sD = 50 mmL = 1000 mf = 0.022

Water flows at a mean velocity of 1.2 m/s through a pipe 1000 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 friction head loss hf.

V = 1.2 m/sL = 1000 mD = 50 mmf = 0.022g = 9.81 m/s²
hf = m
4.Medium
V = 1.7 m/sD = 300 mmL = 300 mf = 0.03

Water flows at a mean velocity of 1.7 m/s through a pipe 300 m long with an inside diameter of 300 mm. Use the Darcy friction factor f = 0.03 and g = 9.81 m/s². Find the friction head loss hf.

V = 1.7 m/sL = 300 mD = 300 mmf = 0.03g = 9.81 m/s²
hf = m
5.Hard
K = 0.2Δz = 34 mL = 300 m, D = 250 mm, f = 0.0154× 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 34 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 = 0.2) 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 = 34 mL = 300 mD = 250 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 0.2Kexit = 1.0
Q = L/s
6.Hard
K = 5Δz = ?L = 100 m, D = 200 mm, f = 0.022× bend (K = 0.3)

Two open reservoirs are joined by a pipe 100 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.02. The minor losses are a square-edged entrance (K = 0.5), 2 bends (K = 0.3 each), a valve (K = 5) 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 80 L/s?

Q = 80 L/sL = 100 mD = 200 mmf = 0.02Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 5Kexit = 1.0
Δz = m

Answer key

  1. 1. Re = 219298
  2. 2. Re = 57.61
  3. 3. hf = 32.29 m
  4. 4. hf = 4.419 m
  5. 5. Q = 277.3 L/s
  6. 6. Δz = 5.652 m

Full step-by-step solutions: practise this topic on examproblems.com.