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 = 12 L/sH = 79 m

A pump delivers 12 L/s of water (ρ = 1000 kg/m³) against a total head of 79 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 12 L/sH = 79 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 100 L/sH = ?

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 4 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 4 kWQ = 100 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 40 L/sH = 34 m

In a test, a pump delivers 40 L/s of water (ρ = 1000 kg/m³) against a head of 34 m while its shaft takes 17.8 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 40 L/sH = 34 mPshaft = 17.8 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 30 L/sH = 68 m

In a test, a pump delivers 30 L/s of water (ρ = 1000 kg/m³) against a head of 68 m while its shaft takes 28.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 30 L/sH = 68 mPshaft = 28.6 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 75 L/sΔz = 22 mL = 500 m, D = 200 mm, f = 0.015, ΣK = 6

A pump moves 75 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 22 m higher. The pipe is 500 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 = 6 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 82%. Find the shaft power Pshaft in kW.

Q = 75 L/sΔz = 22 mL = 500 mD = 200 mmf = 0.015ΣK = 6η = 82%
Pshaft = kW
6.Hard
200 kPa (gauge)PQ = 25 L/sΔz = 6 mL = 100 m, D = 150 mm, f = 0.022, ΣK = 6

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 6 m higher. The pipe is 100 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 = 6 (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 200 kPa. Find the head H the pump must add.

Q = 25 L/sΔz = 6 mL = 100 mD = 150 mmf = 0.022ΣK = 6ptank = 200 kPa
H = m

Answer key

  1. 1. Ph = 9.3 kW
  2. 2. H = 4.077 m
  3. 3. η = 74.95 %
  4. 4. η = 69.97 %
  5. 5. Pshaft = 31.08 kW
  6. 6. H = 28.5 m

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