This whitepaper from the Fluid Sealing Association provides guidance on best practices to minimize the size of the sealing system energy footprint. The first article discussed the energy losses from the interaction between the faces of a mechanical seal. The second discussed the thermal energy required to maintain the proper temperature of the interfacial lubricating fluid. We will now discuss the thermal energy footprint of removing diluents introduced by auxiliary processes.
A flush is often added to the stuffing box or mechanical seal chamber. This helps to extend seal life by displacing solids, removing the heat generated by packing or a mechanical seal, and heat soak from the seal chamber. The flush fluid then becomes mixed with the process fluid as a diluent that may need to be removed from the process fluid.
Figure 1. API Piping Plan 32—energy lost through dilution and vaporization