® Solutia Inc. P.O. Box 66760 St. Louis, Missouri 63166-6760 (314) 674-1000
Pub. No. 7239124B (Supersedes 7239124A)
HEAT TRANSFER SYSTEMEXPANSION TANK DESIGN
The design of the expansion tank in a liquid phase heat transfer system using Therminol® heat transfer fluid or other organic fluids is an important parameter in the total system’ssuccessful operation. An expansion tank correctly installed and maintained can contribute to increased fluid life along with lower maintenance associated with the various mechanical components of thesystem, such as pumps, gaskets, seals and heaters. A properly designed expansion tank can eliminate many problems from the initial startup through everyday operation of the heat transfer system. Thefollowing discussion will explore generally the purpose and design of an expansion tank in a heat transfer system. However, a qualified engineering firm should be consulted in connection with the designof an actual heat transfer system, since considerations outside the scope of this bulletin may be critical. Figure 1
Purpose of the Expansion Tank in a Heat Transfer System
As the term implies,the main function of the expansion tank in a heat transfer system is to provide for fluid expansion, which can be greater than 25% of its original volume depending on the fluid used and the operatingtemperature. Since the tank is usually installed at the highest point in the system, it also can serve as the main venting point of the system for excess levels of low boilers and moisture which mayaccumulate in the heat transfer fluid. The highest point installation also creates positive head pressure to the pump’s inlet, providing flooded pump suction with uninterrupted flow of fluid to the userstation. A simplified drawing showing a suggested positioning of the expansion tank in a heat transfer system is labeled Figure 1.
The Basic System*
*NOTE: This information does not constitute...