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 = 5 L/sH = 64 m

A pump delivers 5 L/s of water (ρ = 1000 kg/m³) against a total head of 64 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 5 L/sH = 64 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
Δp = 200 kPaPQ = 100 L/s

A pump raises the pressure of 100 L/s of water by 200 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 100 L/sΔp = 200 kPa
Ph = kW
3.Medium
PQ = 100 L/sH = 56 m

In a test, a pump delivers 100 L/s of water (ρ = 1000 kg/m³) against a head of 56 m while its shaft takes 91.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 100 L/sH = 56 mPshaft = 91.6 kWg = 9.81 m/s²
η = %
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 6.3 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 15 L/sH = 28 mPshaft = 6.3 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 100 L/sΔz = 7 mL = 500 m, D = 250 mm, f = 0.015, ΣK = 4

A pump moves 100 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 250 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 4 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 100 L/sΔz = 7 mL = 500 mD = 250 mmf = 0.015ΣK = 4
H = m
6.Hard
PQ = 40 L/sΔz = 19 mL = 100 m, D = 150 mm, f = 0.022, ΣK = 5

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 19 m higher. The pipe is 100 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.022; the minor-loss coefficients add up to ΣK = 5 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 80%. Find the shaft power Pshaft in kW.

Q = 40 L/sΔz = 19 mL = 100 mD = 150 mmf = 0.022ΣK = 5η = 80%
Pshaft = kW

Answer key

  1. 1. Ph = 3.139 kW
  2. 2. Ph = 20 kW
  3. 3. η = 59.97 %
  4. 4. η = 65.4 %
  5. 5. H = 14.19 m
  6. 6. Pshaft = 11.84 kW

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