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
Δp = 150 kPaPQ = 40 L/s

A pump raises the pressure of 40 L/s of water by 150 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 40 L/sΔp = 150 kPa
Ph = kW
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 7.5 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 7.5 kWQ = 30 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 25 L/sH = 42 m

In a test, a pump delivers 25 L/s of water (ρ = 1000 kg/m³) against a head of 42 m while its shaft takes 17.2 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 25 L/sH = 42 mPshaft = 17.2 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 50 L/sH = 26 m

In a test, a pump delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 26 m while its shaft takes 15 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 50 L/sH = 26 mPshaft = 15 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 40 L/sΔz = 5 mL = 100 m, D = 200 mm, f = 0.022, ΣK = 8

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 5 m higher. The pipe is 100 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.022; 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 = 40 L/sΔz = 5 mL = 100 mD = 200 mmf = 0.022ΣK = 8
H = m
6.Hard
PQ = 75 L/sΔz = 7 mL = 500 m, D = 200 mm, f = 0.018, ΣK = 6

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 7 m higher. The pipe is 500 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 = 6 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 80%. Find the shaft power Pshaft in kW.

Q = 75 L/sΔz = 7 mL = 500 mD = 200 mmf = 0.018ΣK = 6η = 80%
Pshaft = kW

Answer key

  1. 1. Ph = 6 kW
  2. 2. H = 25.48 m
  3. 3. η = 59.89 %
  4. 4. η = 85.02 %
  5. 5. H = 6.57 m
  6. 6. Pshaft = 20.06 kW

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