US Patent 7300060 Seal staging system

A staged seal assembly having a plurality of staged seals and an external pressure breakdown device connected to the seal assembly and configured to be connected to an external device, wherein each staged seal includes a shaft seal and a seal bypass. The seal bypass includes a pressure breakdown device and directs a portion of fluid through the pressure breakdown device bypassing the respective shaft seal. The staged seal assembly may be configured to be installed in a new installation or replace an existing, seal assembly while substantially maintaining equal pressure reductions across each staged seal and substantially matching the fluid parameters of an external device originally connected to the seal assembly being replaced.