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 = 50 L/sH = ?

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 3 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 3 kWQ = 50 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
PQ = 60 L/sH = 54 m

A pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a total head of 54 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 60 L/sH = 54 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 60 L/sH = 58 m

In a test, a pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 58 m while its shaft takes 41.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 60 L/sH = 58 mPshaft = 41.6 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 150 L/sH = 12 m

A pump delivers 150 L/s of water (ρ = 1000 kg/m³) against a head of 12 m. The pump efficiency is 82% and the electric motor driving it has an efficiency of 95%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 150 L/sH = 12 mηpump = 82%ηmotor = 95%g = 9.81 m/s²
Pel = kW
5.Hard
PQ = 50 L/sΔz = 35 mL = 150 m, D = 150 mm, f = 0.015, ΣK = 6

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 35 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 = 6 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 50 L/sΔz = 35 mL = 150 mD = 150 mmf = 0.015ΣK = 6
H = m
6.Hard
100 kPa (gauge)PQ = 25 L/sΔz = 8 mL = 200 m, D = 150 mm, f = 0.022, ΣK = 8

A pump moves 25 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 8 m higher. The pipe is 200 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.022; the minor-loss coefficients add up to ΣK = 8 (entrance and exit included). Use g = 9.81 m/s². The upper tank is closed and the air above its water is at a gauge pressure of 100 kPa. Find the head H the pump must add.

Q = 25 L/sΔz = 8 mL = 200 mD = 150 mmf = 0.022ΣK = 8ptank = 100 kPa
H = m

Answer key

  1. 1. H = 6.116 m
  2. 2. Ph = 31.78 kW
  3. 3. η = 82.06 %
  4. 4. Pel = 22.67 kW
  5. 5. H = 43.57 m
  6. 6. H = 22 m

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