Pumps & pump power worksheet with answers

Free printable Pumps & pump power 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
PQ = 15 L/sH = ?

A pump delivers 15 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 11 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 11 kWQ = 15 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
Δp = 650 kPaPQ = 12 L/s

A pump raises the pressure of 12 L/s of water by 650 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 12 L/sΔp = 650 kPa
Ph = kW
3.Medium
PQ = 100 L/sH = 50 m

A pump with an efficiency of 78% delivers 100 L/s of water (ρ = 1000 kg/m³) against a head of 50 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 100 L/sH = 50 mη = 78%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 50 L/sH = 34 m

In a test, a pump delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 34 m while its shaft takes 20.3 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 50 L/sH = 34 mPshaft = 20.3 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 50 L/sΔz = 25 mL = 150 m, D = 150 mm, f = 0.015, ΣK = 5

A pump moves 50 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 25 m higher. The pipe is 150 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 5 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 50 L/sΔz = 25 mL = 150 mD = 150 mmf = 0.015ΣK = 5
H = m
6.Hard
PQ = 60 L/sΔz = 7 mL = 150 m, D = 200 mm, f = 0.025, ΣK = 8

A pump moves 60 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 7 m higher. The pipe is 150 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.025; the minor-loss coefficients add up to ΣK = 8 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 72%. Find the shaft power Pshaft in kW.

Q = 60 L/sΔz = 7 mL = 150 mD = 200 mmf = 0.025ΣK = 8η = 72%
Pshaft = kW

Answer key

  1. 1. H = 74.75 m
  2. 2. Ph = 7.8 kW
  3. 3. Pshaft = 62.88 kW
  4. 4. η = 82.15 %
  5. 5. H = 33.16 m
  6. 6. Pshaft = 9.788 kW

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