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
Thematerial of choice for around 30 percent of all PHE gaskets produced isEPDM. Careful compounding of this material type to ensure optimum heatresistance and improved aging has resulted in an EPDM that is capableof operating for a minimum of one year at 347 F/175 C in a hot wateror steam environment.
Material designation: 09-560/E9291
Ahard EPDM material with enhanced chemical resistance was offered to acustomer who had experienced poor performance from a competitor’sgaskets when processing methyl t-butyl ether (MTBE). Gaskets of this compound are now fitted in thecustomer’s PHEs where this medium is in the process stream. Thematerial is a good fit for contact with formaldehyde, organic acids and theamines used for gas sweetening. It is also suitable for chlorateproduction.
Material designation: 26-006/H8ZP1
Acustomer operating in offshore oil and gas exploration required a HNBRwith high-temperature capabilities for use in oil coolers.Maximum hydrolysis resistance of the gasket material was required, ashot water and steam (used in most plate heat exchangers) arepotentially more damaging to HNBR than hydrocarbon products. This grade gasket provides continuous operatingtemperatures up to 347 F/175 C.
