Can plate & frame units be used with steam?
Yes, plate & frame units can be used for steam with a penalty. Steam volume is quite big requiring large entrance area. On the shell and tube heat exchanger, Armstrong oversize the inlet nozzles to accommodate the steam volume. This cannot be easily accommodated on the plate unit. The options are: selecting the next size plate with a larger inlet port (more expensive unit), splitting the steam flow and offering a double steam entrance (one on the fixed header and one on the mobile header). This is not a preferred arrangement (piping layout, difficult service access, special plates with additional portholes, etc.). Gasket temperature is limited to about 300 Deg F. Life expectancy deteriorates rapidly when operating close to the maximum temperature range. Furthermore, when temperatures are exceeded (faulty pressure reducing valve, etc.), gaskets must be replaced (unit will leak).
