If you are required to perform centrifugal pump calculations in your current job assignment, we think you are going to find this website useful.  The site contains numerous on-line calculators.  At this time, we want to introduce you to four handy, easy-to-use centrifugal pump calculators:

• The Brake Horsepower calculator can be used to determine the required centrifugal pump brake horsepower (BHP) for a given flow rate (Q), head (H), specific gravity (S.G.), and efficiency (Eff). When you enter any four of these variables as inputs, the calculator will automatically determine the fifth variable. This is a handy calculator for sizing centrifugal pump driver requirements.
• The Pump Efficiency with Electric Motor Driver is a unique calculator that can be used to determine the centrifugal pump efficiency (eff_p) of a motor driven pump. If you know these five inputs:
  1. Motor KW,
  2. Discharge pressure (P_d),
  3. Suction pressure (P_s)
  4. Flowrate (Q), and
  5. Electric motor efficiency (eff_m).

the calculator will automatically determine the current pump efficiency. This is a handy calculator for evaluating a centrifugal pump’s hydraulic condition in the field.

• The Specific Speed (US) calculator can be used to determine a centrifugal pump’s specific speed (N_s) if you know the flow rate (Q), head (H), rotational speed (N). If you enter any three of these variables as inputs, the calculator will determine the fourth variable.  A pumps specific speed is an indicator of the basic geometry of the impeller, i.e. low specific speed pumps tend to have large outside diameters and narrow, radial flow passages while high specific speed pumps tend to have small outside diameters and large, more axial flow passages. Pumps of the same specific speed can be scaled up or down for greater or less flow and head requirements.
• The Suction Specific Speed calculator can be used to determine a centrifugal pump’s suction specific speed (N_ss) for a given flow rate (Q), suction head required (NPSHr), rotational speed (N). If you enter any three of these variables as inputs, the calculator will determine the fourth variable. A pump’s suction specific speed is an indicator of an impellers flow stability at low flows.

Give these calculators a try and let us know what you think.