Extreme temperatures challenge the performance and longevity of plate heat exchanger gaskets. Three materials recently developed by Trelleborg Sealing Solutions, Ft. Wayne, Ind., fight back.

"Gaskets are critical elements within a PHE and potentially their weakest link," says Jon Cutler, Trelleborg's material development manager for plate heat exchanger gaskets. "We're taking gasket compounds to the limits of their performance. Great efforts have been made to ensure gasket material longevity at high temperatures and pressures." Trelleborg has been making gaskets for 25 years.

The design concept for all plate heat exchangers is basically the same. A series of thin metal plates runs between two metal end plates. The liquid to be processed is pumped into one side of the plates while the liquid facilitating heating and cooling is pumped into the other. The key to the process is that both liquids come into contact with maximum plate surface area to rapidly exchange heat from one liquid to the other.

The plates within the gasketed plate heat exchangers are sealed with a rubber gasket that prevents liquids within the unit from leaking out or mixing with other fluids. Temperatures can run to extremes from -49 to 392°F (-45 to 200°C), and chemicals can be exceptionally aggressive. Pressures also are high, generally between 72 and 218 psi, but sometimes even up to 508 psi.