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 = 60 m

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) against a total head of 60 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 50 L/sH = 60 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
Δp = 800 kPaPQ = 20 L/s

A pump raises the pressure of 20 L/s of water by 800 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 20 L/sΔp = 800 kPa
Ph = kW
3.Medium
PQ = 25 L/sH = 22 m

A pump with an efficiency of 80% delivers 25 L/s of water (ρ = 1000 kg/m³) against a head of 22 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 25 L/sH = 22 mη = 80%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 50 L/sH = 48 m

A pump with an efficiency of 65% delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 48 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 50 L/sH = 48 mη = 65%g = 9.81 m/s²
Pshaft = kW
5.Hard
PQ = 40 L/sΔz = 20 mL = 400 m, D = 150 mm, f = 0.02, 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 20 m higher. The pipe is 400 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.02; 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 = 20 mL = 400 mD = 150 mmf = 0.02ΣK = 8
H = m
6.Hard
PQ = 50 L/sΔz = 9 mL = 500 m, D = 150 mm, f = 0.015, ΣK = 6

A pump moves 50 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 500 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 50 L/sΔz = 9 mL = 500 mD = 150 mmf = 0.015ΣK = 6
H = m

Answer key

  1. 1. Ph = 29.43 kW
  2. 2. Ph = 16 kW
  3. 3. Pshaft = 6.744 kW
  4. 4. Pshaft = 36.22 kW
  5. 5. H = 36.02 m
  6. 6. H = 31.85 m

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