You can connect steam to the quench connection and use it to put out a fire, should it occur on the outboard side of the seal. In this application the flush connection is not used. A large diameter cooled sealing chamber should be installed on the pump. To allow centrifugal force to throw solid coke particles away from the seal faces and sliding or flexing components Misalignment is always a problem in these pumps. This shaft displacement can cause the rotating seal to rub against stationary parts in a conventional stuffing box.
Vibration means movement .
The seal must be free to move within the seal chamber. When the pump stops gravity will pull solid particles to the bottom of the stuffing box. A large seal chamber will almost guarantee that the particles will not collect around the seal at this time. A Cartridge seal is necessary. Thermal growth will cause volute casing and shaft expansion.