A catastrophic failure of a centrifugal pump can occur if the liquid within the pump casing is allowed to vaporize. To prevent flashing due to overheating of the fluid, a flow must be maintained through the pump to keep the liquid below saturation temperature.

If a temperature rise of 15 oF is accepted in the casing - minimum flow through a centrifugal pump can be calculated as
q = PBHP / 2.95 cp SG (1)
where
q = minimum flow rate (gpm)
PBHP = power input (BHP)
cp = specific heat capacity (Btu/lb oF)
SG = specific gravity of the fluid