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 = 100 L/sH = 57 m

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) against a total head of 57 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 100 L/sH = 57 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 10 L/sH = 46 m

A pump delivers 10 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 = 10 L/sH = 46 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 15 L/sH = 36 m

In a test, a pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a head of 36 m while its shaft takes 7.1 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 15 L/sH = 36 mPshaft = 7.1 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 20 L/sH = 30 m

In a test, a pump delivers 20 L/s of water (ρ = 1000 kg/m³) against a head of 30 m while its shaft takes 8.2 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 20 L/sH = 30 mPshaft = 8.2 kWg = 9.81 m/s²
η = %
5.Hard
300 kPa (gauge)PQ = 120 L/sΔz = 5 mL = 150 m, D = 250 mm, f = 0.015, 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 5 m higher. The pipe is 150 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.015; 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 300 kPa. Find the head H the pump must add.

Q = 120 L/sΔz = 5 mL = 150 mD = 250 mmf = 0.015ΣK = 8ptank = 300 kPa
H = m
6.Hard
PQ = 120 L/sΔz = 11 mL = 500 m, D = 250 mm, f = 0.02, ΣK = 6

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 11 m higher. The pipe is 500 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.02; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 85%. Find the shaft power Pshaft in kW.

Q = 120 L/sΔz = 11 mL = 500 mD = 250 mmf = 0.02ΣK = 6η = 85%
Pshaft = kW

Answer key

  1. 1. Ph = 55.92 kW
  2. 2. Ph = 4.513 kW
  3. 3. η = 74.61 %
  4. 4. η = 71.78 %
  5. 5. H = 40.76 m
  6. 6. Pshaft = 34.64 kW

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