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 = 25 L/sH = ?

A pump delivers 25 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 5.5 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 5.5 kWQ = 25 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
Δp = 550 kPaPQ = 5 L/s

A pump raises the pressure of 5 L/s of water by 550 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 5 L/sΔp = 550 kPa
Ph = kW
3.Medium
PQ = 25 L/sH = 34 m

In a test, a pump delivers 25 L/s of water (ρ = 1000 kg/m³) against a head of 34 m while its shaft takes 11.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 25 L/sH = 34 mPshaft = 11.6 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 60 L/sH = 42 m

A pump with an efficiency of 70% delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 42 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 60 L/sH = 42 mη = 70%g = 9.81 m/s²
Pshaft = kW
5.Hard
PQ = 50 L/sΔz = 5 mL = 200 m, D = 150 mm, f = 0.025, ΣK = 2.5

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 5 m higher. The pipe is 200 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.025; the minor-loss coefficients add up to ΣK = 2.5 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 50 L/sΔz = 5 mL = 200 mD = 150 mmf = 0.025ΣK = 2.5
H = m
6.Hard
PQ = 10 L/sΔz = 5 mL = 100 m, D = 100 mm, f = 0.025, ΣK = 8

A pump moves 10 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 5 m higher. The pipe is 100 m long with an inside diameter of 100 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 82%. Find the shaft power Pshaft in kW.

Q = 10 L/sΔz = 5 mL = 100 mD = 100 mmf = 0.025ΣK = 8η = 82%
Pshaft = kW

Answer key

  1. 1. H = 22.43 m
  2. 2. Ph = 2.75 kW
  3. 3. η = 71.88 %
  4. 4. Pshaft = 35.32 kW
  5. 5. H = 19.62 m
  6. 6. Pshaft = 0.9244 kW

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