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 = 10 L/sH = ?

A pump delivers 10 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 2.2 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 2.2 kWQ = 10 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
PQ = 30 L/sH = ?

A pump delivers 30 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 15 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 15 kWQ = 30 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 40 L/sH = 66 m

In a test, a pump delivers 40 L/s of water (ρ = 1000 kg/m³) against a head of 66 m while its shaft takes 39.8 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 40 L/sH = 66 mPshaft = 39.8 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 60 L/sH = 18 m

A pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 18 m. The pump efficiency is 82% and the electric motor driving it has an efficiency of 90%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 60 L/sH = 18 mηpump = 82%ηmotor = 90%g = 9.81 m/s²
Pel = kW
5.Hard
100 kPa (gauge)PQ = 75 L/sΔz = 14 mL = 300 m, D = 200 mm, f = 0.018, ΣK = 8

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 14 m higher. The pipe is 300 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.018; 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 = 75 L/sΔz = 14 mL = 300 mD = 200 mmf = 0.018ΣK = 8ptank = 100 kPa
H = m
6.Hard
350 kPa (gauge)PQ = 20 L/sΔz = 12 mL = 150 m, D = 100 mm, f = 0.015, ΣK = 8

A pump moves 20 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 100 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 350 kPa. Find the head H the pump must add.

Q = 20 L/sΔz = 12 mL = 150 mD = 100 mmf = 0.015ΣK = 8ptank = 350 kPa
H = m

Answer key

  1. 1. H = 22.43 m
  2. 2. H = 50.97 m
  3. 3. η = 65.07 %
  4. 4. Pel = 14.36 kW
  5. 5. H = 34.36 m
  6. 6. H = 57.76 m

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