Plan 23


Product recirculation from seal chamber to heat exchanger and back to seal chamber


  • Circulation is maintained by a pumping ring when pump is energized
  • When pump is idle, circulation is maintained by thermosiphon effect
  • Provides lower product stabilization temperature
  • Can establish required fluid vapor point margin

For use:

  • In hot and clean service such as boiler feed water and hot hydrocarbon services


  • Maintain less than 20” horizontal distance from seal chamber to heat exchanger
  • Vent valve required at highest point of the piping system
  • Seal chamber must have a close clearance throat bushing
  • The seal outlet port must be facing up
  • The cooler must be mounted above the pump centerline
  • Fully vent the system before start up