A behind the rotor seal is a type of mechanical seal that is located directly behind the rotor, isolating the shaft bushings or bearings from the pumped liquid. This type of seal is an alternative to seals that are located in the stuffing box of the pump.

Because the rotating shaft is not being lubricated by the process liquid, the bracket must be filled with an application appropriate grease. A lip seal is installed in the face of the bracket to maintain the grease barrier.