Centrifugal pressure is the pressure acting radially outward on the lubrication film as a function of the speed of rotation.
It is calculated with the following formula:

p_Z =

g = specific weight

b = sealing width

v_g = peripheral

g = acceleration due to gravity

d_m = mean sliding face diameter 

In seals pressurized from the outside, the centrifugal pressure acts counter to the pressure differential to be sealed; in seals pressurized from the inside, the pressures act cumulatively. Consequently, a seal pressurized from the inside has up to ten times more leakage than a mechanical seal pressurized from the outside under otherwise equivalent conditions. With high-speed mechanical seals care must be taken to ensure the pressure to be sealed exceeds the centrifugal pressure so as to guarantee a safe build-up of lubricating film.