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 = 200 L/sH = 46 m

A pump delivers 200 L/s of water (ρ = 1000 kg/m³) against a total head of 46 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 200 L/sH = 46 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 150 L/sH = 10 m

A pump delivers 150 L/s of water (ρ = 1000 kg/m³) against a total head of 10 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 150 L/sH = 10 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 25 L/sH = 28 m

A pump with an efficiency of 72% delivers 25 L/s of water (ρ = 1000 kg/m³) against a head of 28 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 25 L/sH = 28 mη = 72%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 30 L/sH = 52 m

In a test, a pump delivers 30 L/s of water (ρ = 1000 kg/m³) against a head of 52 m while its shaft takes 21.9 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 30 L/sH = 52 mPshaft = 21.9 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 120 L/sΔz = 26 mL = 100 m, D = 250 mm, f = 0.025, ΣK = 8

A pump moves 120 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 26 m higher. The pipe is 100 m long with an inside diameter of 250 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. Find the head H the pump must add.

Q = 120 L/sΔz = 26 mL = 100 mD = 250 mmf = 0.025ΣK = 8
H = m
6.Hard
PQ = 40 L/sΔz = 11 mL = 400 m, D = 150 mm, f = 0.018, ΣK = 5

A pump moves 40 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 11 m higher. The pipe is 400 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.018; the minor-loss coefficients add up to ΣK = 5 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 65%. Find the shaft power Pshaft in kW.

Q = 40 L/sΔz = 11 mL = 400 mD = 150 mmf = 0.018ΣK = 5η = 65%
Pshaft = kW

Answer key

  1. 1. Ph = 90.25 kW
  2. 2. Ph = 14.71 kW
  3. 3. Pshaft = 9.537 kW
  4. 4. η = 69.88 %
  5. 5. H = 31.48 m
  6. 6. Pshaft = 15 kW

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