NPSHa centrifugal pump analysis

  1. This guide helps you calculate the net positive suction head available for your given process conditions. You can even allow for a safety NPSHa margin to ensure safe operation of your pump.
  2. You can analyze both flooded and lift conditions.
  1. Val Lobanoff and Robert Ross, Centrifugal Pumps--Design and Application, 2nd edition (Houston: Gulf Publishing Company, 1992), 104-106.

Step 1: Process Data Inputs
1.1 Fluid (eg butane)
1.2 Pumping Temperature (F)
1.3 Barometric Pressure, in psia
1.4 Pressure on the surface of the liquid in a closed suction tank, in psig
(Use zero (0) psig for sumps and ATMS. tanks )
1.5 Vapor Pressure at the maximum pumping temperature, in psia
1.6 Fluid's Specific Gravity
1.7 Elevation head in feet (Use positive value for flooded suction, use negative value for lifting suction)
1.8 Friction loss in feet in the suction pipe at the required capacity
1.9 Required NPSH margin in feet
Step 2: Solve
2.1 Proof steps
2.2 Solve for the NPSHa centrifugal pump