Thermosyphon Cooling System is designed to dissipate the heat from mechanical seals during operation. Thermosyphon is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. The barrier/buffer fluid is circulated to the seal and back to the system by the Thermosyphon effect which means the hotter, lower density water will rise while the cooler, higher density water will sink. It is used for double mechanical seals to provide necessary lubrication and cooling to the seal faces to achieve recommended seal life. This is equipped with a cooling coil inside the shell to bring down the temperature of barrier fluid coming from the seal to the Thermosyphon vessel.