During operation of the plate-shell heat exchanger, it is recommended to check the sealing gaskets between plates for any signs of leakage every shift, with particular attention to operating conditions where the medium temperature approaches the upper temperature limit of the gaskets. If loose fastening bolts are found, they should be uniformly retightened in a diagonal sequence to avoid deformation of plates caused by one-sided overload. The gasket material should be selected from nitrile, EPDM, or fluororubber according to the medium temperature, and gaskets from different batches must not be mixed on site.
When cleaning the plates, avoid using chlorine-containing cleaning agents on 304 stainless steel plates; for 316L or titanium plates, the concentration of the cleaning solution must also be controlled. Before disassembly, record the plate arrangement order, and when reassembling, restore them according to the original flow sequence to prevent flow path confusion that could affect heat exchange performance. Metal scrapers must not be used to clean the sealing surfaces of the plates; it is recommended to wipe them with a soft cloth and a neutral cleaning agent.
During long-term shutdown, the internal medium should be drained, and the compression bolts should be loosened until the plates are in a free state to avoid the gaskets losing elasticity due to long-term compression. Spare parts should be stored away from light and moisture; gaskets are recommended to be laid flat and must not be hung. Before restarting, confirm that the plates have no cracks and the gaskets are not aged, and increase the pressure to the working pressure in stages.
