A process fluid lubricated pump includes a pump having a pump shaft extending from a drive end to a non-drive end to rotate about an axial direction, a first pump section having a first set of impellers fixedly mounted on the pump shaft to increase the pressure of the process fluid, a drive to exert a torque on the drive end of the pump shaft to drive the rotation of the pump shaft, a first balance drum fixedly connected to the pump shaft between the pump and the drive end of the pump shaft, the first balance drum defining a first front side facing the pump and a first back side, and a second balance drum fixedly connected to the pump shaft between the pump and the non-drive end of the pump shaft, the second balance drum defining a second front side facing the pump and a second back side.