US Patent 11391374 Dual ring stuffing box

A system includes a pressure ring positioned to abut a fluid end face, the pressure ring having a pressure ring bore with a diameter larger than a fluid end bore diameter. The system also includes an adjacent ring coupled to a fluid end, the pressure ring positioned between the adjacent ring and the fluid end face. The system further includes a face seal positioned at an interface of the pressure ring and the fluid end face, the face seal containing pressurized fluid associated with the fluid end. The system also includes packing material positioned within at least a portion of the pressure ring bore.