An inducer is the axial inlet portion of a centrifugal pump rotor, the function of which is to raise the inlet head by an amount sufficient to prevent significant cavitation in the following pump stage. [1] It is used in applications in which the inlet pressure of a pump is close to the vapor pressure of the pumped liquid. Inducers are frequently included in design of turbopumps for liquid propellant rocket engines, although they are used in other applications which require high suction performance. [2] It does not increase NPSHa but decreases NPSHr for Pump[citation needed]