Trelleborg Sealing Solutions has developed three materials specifically designed for gaskets fitted to Plate Heat Exchanger systems — material designation 09-538/E8ZP4; material designation 09-560/E9291; and material designation 26-006/H8ZP1. The plates within PHEs are sealed with a rubber gasket that prevents the liquids within the PHE from leaking out or mixing.
Sealing in PHEs is challenging. Temperatures are at extremes from -49 F to 392 F /-45 C to 200 C, while chemicals are exceptionally aggressive. Pressures are also high, generally between 72 PSI and 218 PSI/ five and 15 bar but sometimes even up to 508 psi / 35 bar. The design concept for all PHEs is the same. Between two metal end plates there is a series of thin metal 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 the maximum plate surface area to rapidly exchange heat from one liquid to the other. In processing plant PHEs can be up to five meters/16 feet in height.
Material designation: 09-538/E8ZP4
The material of choice for around 30 percent of all PHE gaskets produced is EPDM. Careful compounding of this material type to ensure optimum heat resistance and improved aging has resulted in an EPDM that is capable of operating for a minimum of one year at 347 F/175 C in a hot water or steam environment.
Material designation: 09-560/E9291
A hard EPDM material with enhanced chemical resistance was offered to a customer who had experienced poor performance from a competitor’s gaskets when processing methyl t-butyl ether (MTBE). Gaskets of this compound are now fitted in the customer’s PHEs where this medium is in the process stream. The material is a good fit for contact with formaldehyde, organic acids and the amines used for gas sweetening. It is also suitable for chlorate production.
Material designation: 26-006/H8ZP1
A customer operating in offshore oil and gas exploration required a HNBR with high-temperature capabilities for use in oil coolers. Maximum hydrolysis resistance of the gasket material was required, as hot water and steam (used in most plate heat exchangers) are potentially more damaging to HNBR than hydrocarbon products. This grade gasket provides continuous operating temperatures up to 347 F/175 C.