Be the Pump Designer

  1. This guide allows you to input basic pumping requirements, along with the desired operating speed and number of stages, in order to determine your hypothetical pump's specific speed and suction specific speed. The guide will also let you know if your specific speed is too low, or your suction specific speed is too high, and will help you estimate horsepower requirements.
  2. This is an excellent tool for screening potential pump designs during the initial phases of a project.
  1. The selected pump will be operating at its best efficiency point.
  2. The selected pump's efficiency is estimated from historical efficiency versus specific speed data.
  3. Double suction impeller efficiencies will follow the same historical efficiency versus specific speed data as single suction impellers.
  4. For multistage impellers, all stages have the same specific speed.
  5. For multistage impellers, all stages have the same impeller diameters.
  6. Suction specific speeds should lie below 11,000.
  1. Based on the Pumps & Systems article titled "PumpCalcs: Be the Pump Designer." Click on this link to view the article:
  2. Igor Karassik et al, Pump Handbook (McGraw-Hill Book Company, 1976), 2-20.

Step 1: Process Data Inputs
1.1 RPM
1.2 Flow @ BEP (gpm)
1.3 Suction Pressure (psi)
1.4 Discharge Pressure (psi)
1.5 Specific Gravity
1.6 Estimated Efficiency (percentage)
1.7 NPSHa (ft) @ BEP
1.8 NPSH safety margin (ft)
1.9 Number of suction eye(s)
1.10 Number of stages
Step 2: Solve
2.1 Proof steps
2.2 Solve for the centrifugal pump