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 = ?

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 22 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 22 kWQ = 100 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
Δp = 600 kPaPQ = 15 L/s

A pump raises the pressure of 15 L/s of water by 600 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 15 L/sΔp = 600 kPa
Ph = kW
3.Medium
PQ = 40 L/sH = 16 m

A pump delivers 40 L/s of water (ρ = 1000 kg/m³) against a head of 16 m. The pump efficiency is 80% and the electric motor driving it has an efficiency of 95%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 40 L/sH = 16 mηpump = 80%ηmotor = 95%g = 9.81 m/s²
Pel = kW
4.Medium
PQ = 15 L/sH = 28 m

In a test, a pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a head of 28 m while its shaft takes 6.9 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 15 L/sH = 28 mPshaft = 6.9 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 60 L/sΔz = 10 mL = 200 m, D = 250 mm, f = 0.018, ΣK = 8

A pump moves 60 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 10 m higher. The pipe is 200 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 = 8 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 60 L/sΔz = 10 mL = 200 mD = 250 mmf = 0.018ΣK = 8
H = m
6.Hard
PQ = 15 L/sΔz = 16 mL = 300 m, D = 100 mm, f = 0.018, ΣK = 8

A pump moves 15 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 16 m higher. The pipe is 300 m long with an inside diameter of 100 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. Find the head H the pump must add.

Q = 15 L/sΔz = 16 mL = 300 mD = 100 mmf = 0.018ΣK = 8
H = m

Answer key

  1. 1. H = 22.43 m
  2. 2. Ph = 9 kW
  3. 3. Pel = 8.261 kW
  4. 4. η = 59.71 %
  5. 5. H = 11.71 m
  6. 6. H = 27.53 m

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