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 = 400 kPaPQ = 8 L/s

A pump raises the pressure of 8 L/s of water by 400 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 8 L/sΔp = 400 kPa
Ph = kW
2.Easy
PQ = 100 L/sH = ?

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 22 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 22 kWQ = 100 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 80 L/sH = 44 m

A pump with an efficiency of 78% delivers 80 L/s of water (ρ = 1000 kg/m³) against a head of 44 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 80 L/sH = 44 mη = 78%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 15 L/sH = 38 m

In a test, a pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a head of 38 m while its shaft takes 7.5 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 15 L/sH = 38 mPshaft = 7.5 kWg = 9.81 m/s²
η = %
5.Hard
400 kPa (gauge)PQ = 50 L/sΔz = 13 mL = 400 m, D = 150 mm, f = 0.018, 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 13 m higher. The pipe is 400 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.018; the minor-loss coefficients add up to ΣK = 6 (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 400 kPa. Find the head H the pump must add.

Q = 50 L/sΔz = 13 mL = 400 mD = 150 mmf = 0.018ΣK = 6ptank = 400 kPa
H = m
6.Hard
200 kPa (gauge)PQ = 50 L/sΔz = 22 mL = 100 m, D = 150 mm, f = 0.02, ΣK = 4

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 22 m higher. The pipe is 100 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 = 4 (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 200 kPa. Find the head H the pump must add.

Q = 50 L/sΔz = 22 mL = 100 mD = 150 mmf = 0.02ΣK = 4ptank = 200 kPa
H = m

Answer key

  1. 1. Ph = 3.2 kW
  2. 2. H = 22.43 m
  3. 3. Pshaft = 44.27 kW
  4. 4. η = 74.56 %
  5. 5. H = 75.81 m
  6. 6. H = 49.46 m

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