

Seal Stability & Dowtherm™
Daniel Cohen
Market Developer - Dow Glycol Heat Transfer Fluids
September 2020
Dowtherm™ & High Temperature Systems
2020 has been stuffed full of challenges and change and your heat transfer equipment has been the most consistent performer amidst all the volatility. One of the trends that we have seen recently is that when facilities are coming back online or conducting maintenance, some of the seals have shrunk or have begun leaking. This is a direct result of taking a continuous, hot system that has been accustomed to running 24/7 and subjecting components to an abrupt cool down during jurisdictional shutdowns. It is very important to make sure that as you restart a system, there is enough safety stock of Dowtherm™ on hand to fulfill the system requirements. The shelf life is indefinite, and the risk of running out is very real and very probable if a seal unexpectedly leaks.


Seal Thermal Ranges
When evaluating seals & elastomers, the recommended materials & their optimum service temperature ranges are listed below;
Fluorosilicone | -100°F to 350°F |
Perfluoro Rubber | 5°F to 500°F |
Tetrafluoroethylene-Propylene (AFLAS®) | 23°F to 338°F |
Expanded PTFE (Gore-Tex®) | -450°F to 550°F |
Graphite (Grafoil®) | -400°F to 1600°F |
Fluorocarbon Rubber (Viton®) | -20°F to 450°F |