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 = 60 L/sH = 39 m

A pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a total head of 39 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 60 L/sH = 39 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 50 L/sH = ?

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 22 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 22 kWQ = 50 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 80 L/sH = 38 m

In a test, a pump delivers 80 L/s of water (ρ = 1000 kg/m³) against a head of 38 m while its shaft takes 37.3 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 80 L/sH = 38 mPshaft = 37.3 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 60 L/sH = 46 m

A pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 46 m. The pump efficiency is 82% and the electric motor driving it has an efficiency of 92%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 60 L/sH = 46 mηpump = 82%ηmotor = 92%g = 9.81 m/s²
Pel = kW
5.Hard
PQ = 60 L/sΔz = 5 mL = 100 m, D = 200 mm, f = 0.015, ΣK = 2.5

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 5 m higher. The pipe is 100 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 2.5 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 65%. Find the shaft power Pshaft in kW.

Q = 60 L/sΔz = 5 mL = 100 mD = 200 mmf = 0.015ΣK = 2.5η = 65%
Pshaft = kW
6.Hard
PQ = 20 L/sΔz = 37 mL = 150 m, D = 100 mm, f = 0.018, ΣK = 8

A pump moves 20 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 37 m higher. The pipe is 150 m long with an inside diameter of 100 mm and a Darcy friction factor f = 0.018; the minor-loss coefficients add up to ΣK = 8 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 65%. Find the shaft power Pshaft in kW.

Q = 20 L/sΔz = 37 mL = 150 mD = 100 mmf = 0.018ΣK = 8η = 65%
Pshaft = kW

Answer key

  1. 1. Ph = 22.96 kW
  2. 2. H = 44.85 m
  3. 3. η = 79.95 %
  4. 4. Pel = 35.89 kW
  5. 5. Pshaft = 6.211 kW
  6. 6. Pshaft = 14.66 kW

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