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 = 60 L/sH = 6 m

A pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a total head of 6 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 60 L/sH = 6 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
Δp = 200 kPaPQ = 50 L/s

A pump raises the pressure of 50 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 = 50 L/sΔp = 200 kPa
Ph = kW
3.Medium
PQ = 40 L/sH = 16 m

A pump with an efficiency of 80% delivers 40 L/s of water (ρ = 1000 kg/m³) against a head of 16 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 40 L/sH = 16 mη = 80%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 10 L/sH = 18 m

In a test, a pump delivers 10 L/s of water (ρ = 1000 kg/m³) against a head of 18 m while its shaft takes 2.4 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 10 L/sH = 18 mPshaft = 2.4 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 80 L/sΔz = 5 mL = 200 m, D = 200 mm, f = 0.025, 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 5 m higher. The pipe is 200 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.025; 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 = 5 mL = 200 mD = 200 mmf = 0.025ΣK = 3
H = m
6.Hard
300 kPa (gauge)PQ = 25 L/sΔz = 5 mL = 100 m, D = 150 mm, f = 0.015, ΣK = 8

A pump moves 25 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 150 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 8 (entrance and exit included). Use g = 9.81 m/s². The upper tank is closed and the air above its water is at a gauge pressure of 300 kPa. Find the head H the pump must add.

Q = 25 L/sΔz = 5 mL = 100 mD = 150 mmf = 0.015ΣK = 8ptank = 300 kPa
H = m

Answer key

  1. 1. Ph = 3.532 kW
  2. 2. Ph = 10 kW
  3. 3. Pshaft = 7.848 kW
  4. 4. η = 73.58 %
  5. 5. H = 14.25 m
  6. 6. H = 37.42 m

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