valve 91 is set to a fully open position and blower 94 is turned on blower 94 draws air flow through the vent tube to lower pressure inside the sump cavities 112 122 and 132 to approximately 14 0 psi and draw an air oil mixture to the air oil separator 92 which removes the oil from the mixture which is returned to the oil sump cavities 112 122 and 132 through oil tank 86 fig3 and 7 illustrate schematically a system having three sump cavities 112 122 and 132 but it is to be understood that the oil sump pressurization system described can be employed to control pressurization of a single sump cavity surrounding a single bearing assembly or a large number of bearing assemblies or can be used with a plurality of separate vent tubes including a separately controlled valves connected individually to separate bearing assemblies so that each may be individually controlled fig1 illustrates an sump lubrication system in which air flow through sump vent tubes 34 36 and 38 is separately controlled by respective adjustable valves 35 37 and 39 each of adjustable valves 35 37 and 39 may be set to a unique setting to restrict flow in each respective sump vent tube 34 36 and 38 at a separate flow rate from the other flow tubes to allow a predetermined air flow through the respective sump vent tubes 34 36 and 38 to maintain oil air flow into the air oil separator during all operating conditions certain operating conditions may require that one of the adjustable valves 35 37 or 39 be.