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 = 5 L/sH = 64 m

A pump delivers 5 L/s of water (ρ = 1000 kg/m³) against a total head of 64 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 5 L/sH = 64 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 8 L/sH = 9 m

A pump delivers 8 L/s of water (ρ = 1000 kg/m³) against a total head of 9 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 8 L/sH = 9 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 150 L/sH = 38 m

In a test, a pump delivers 150 L/s of water (ρ = 1000 kg/m³) against a head of 38 m while its shaft takes 65.8 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 150 L/sH = 38 mPshaft = 65.8 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 15 L/sH = 24 m

In a test, a pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a head of 24 m while its shaft takes 5 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 15 L/sH = 24 mPshaft = 5 kWg = 9.81 m/s²
η = %
5.Hard
300 kPa (gauge)PQ = 120 L/sΔz = 7 mL = 300 m, D = 250 mm, f = 0.018, ΣK = 4

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 7 m higher. The pipe is 300 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.018; the minor-loss coefficients add up to ΣK = 4 (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 = 7 mL = 300 mD = 250 mmf = 0.018ΣK = 4ptank = 300 kPa
H = m
6.Hard
PQ = 40 L/sΔz = 12 mL = 150 m, D = 150 mm, f = 0.02, ΣK = 4

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 12 m higher. The pipe is 150 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.02; the minor-loss coefficients add up to ΣK = 4 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 40 L/sΔz = 12 mL = 150 mD = 150 mmf = 0.02ΣK = 4
H = m

Answer key

  1. 1. Ph = 3.139 kW
  2. 2. Ph = 0.7063 kW
  3. 3. η = 84.98 %
  4. 4. η = 70.63 %
  5. 5. H = 45.38 m
  6. 6. H = 18.27 m

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