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 = 8 L/sH = 47 m

A pump delivers 8 L/s of water (ρ = 1000 kg/m³) against a total head of 47 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 8 L/sH = 47 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 150 L/sH = 53 m

A pump delivers 150 L/s of water (ρ = 1000 kg/m³) against a total head of 53 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 150 L/sH = 53 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 100 L/sH = 34 m

In a test, a pump delivers 100 L/s of water (ρ = 1000 kg/m³) against a head of 34 m while its shaft takes 47.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 100 L/sH = 34 mPshaft = 47.6 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 20 L/sH = 10 m

In a test, a pump delivers 20 L/s of water (ρ = 1000 kg/m³) against a head of 10 m while its shaft takes 2.4 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 20 L/sH = 10 mPshaft = 2.4 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 25 L/sΔz = 7 mL = 150 m, D = 150 mm, f = 0.025, 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 7 m higher. The pipe is 150 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.025; 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 = 25 L/sΔz = 7 mL = 150 mD = 150 mmf = 0.025ΣK = 6
H = m
6.Hard
150 kPa (gauge)PQ = 80 L/sΔz = 34 mL = 400 m, D = 200 mm, f = 0.02, ΣK = 8

A pump moves 80 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 34 m higher. The pipe is 400 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.02; 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 150 kPa. Find the head H the pump must add.

Q = 80 L/sΔz = 34 mL = 400 mD = 200 mmf = 0.02ΣK = 8ptank = 150 kPa
H = m

Answer key

  1. 1. Ph = 3.689 kW
  2. 2. Ph = 77.99 kW
  3. 3. η = 70.07 %
  4. 4. η = 81.75 %
  5. 5. H = 10.16 m
  6. 6. H = 65.15 m

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