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 = 600 kPaPQ = 10 L/s

A pump raises the pressure of 10 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 = 10 L/sΔp = 600 kPa
Ph = kW
2.Easy
PQ = 30 L/sH = 14 m

A pump delivers 30 L/s of water (ρ = 1000 kg/m³) against a total head of 14 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 30 L/sH = 14 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 40 L/sH = 30 m

A pump with an efficiency of 72% delivers 40 L/s of water (ρ = 1000 kg/m³) against a head of 30 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 40 L/sH = 30 mη = 72%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 100 L/sH = 66 m

A pump with an efficiency of 72% delivers 100 L/s of water (ρ = 1000 kg/m³) against a head of 66 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 100 L/sH = 66 mη = 72%g = 9.81 m/s²
Pshaft = kW
5.Hard
PQ = 120 L/sΔz = 7 mL = 100 m, D = 250 mm, f = 0.018, ΣK = 5

A pump moves 120 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 100 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 = 5 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 120 L/sΔz = 7 mL = 100 mD = 250 mmf = 0.018ΣK = 5
H = m
6.Hard
PQ = 120 L/sΔz = 32 mL = 500 m, D = 250 mm, f = 0.018, ΣK = 8

A pump moves 120 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 32 m higher. The pipe is 500 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. The pump efficiency is 70%. Find the shaft power Pshaft in kW.

Q = 120 L/sΔz = 32 mL = 500 mD = 250 mmf = 0.018ΣK = 8η = 70%
Pshaft = kW

Answer key

  1. 1. Ph = 6 kW
  2. 2. Ph = 4.12 kW
  3. 3. Pshaft = 16.35 kW
  4. 4. Pshaft = 89.92 kW
  5. 5. H = 10.72 m
  6. 6. Pshaft = 76.35 kW

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