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 = 50 L/sH = ?

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 45 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 45 kWQ = 50 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 30 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 30 kWQ = 30 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 10 L/sH = 26 m

A pump with an efficiency of 75% delivers 10 L/s of water (ρ = 1000 kg/m³) against a head of 26 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 10 L/sH = 26 mη = 75%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 80 L/sH = 74 m

A pump with an efficiency of 85% delivers 80 L/s of water (ρ = 1000 kg/m³) against a head of 74 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 80 L/sH = 74 mη = 85%g = 9.81 m/s²
Pshaft = kW
5.Hard
PQ = 75 L/sΔz = 9 mL = 150 m, D = 200 mm, f = 0.015, ΣK = 2.5

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 9 m higher. The pipe is 150 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 2.5 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 85%. Find the shaft power Pshaft in kW.

Q = 75 L/sΔz = 9 mL = 150 mD = 200 mmf = 0.015ΣK = 2.5η = 85%
Pshaft = kW
6.Hard
PQ = 80 L/sΔz = 6 mL = 300 m, D = 200 mm, f = 0.02, ΣK = 3

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 6 m higher. The pipe is 300 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 = 3 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 80 L/sΔz = 6 mL = 300 mD = 200 mmf = 0.02ΣK = 3
H = m

Answer key

  1. 1. H = 91.74 m
  2. 2. H = 101.9 m
  3. 3. Pshaft = 3.401 kW
  4. 4. Pshaft = 68.32 kW
  5. 5. Pshaft = 11.25 kW
  6. 6. H = 16.91 m

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