Fluid seeping from gasket edges and gasket hardening and cracking are among the problems most frequently reported after plate heat exchangers are put into service. Based on field troubleshooting experience, the cause of leakage often lies not in the gasket itself but in how well the medium and gasket material were matched during the selection stage.
When the medium contains aromatic hydrocarbons, ketones, or high concentrations of acidic or alkaline components, conventional nitrile gaskets may swell and harden, thereby losing their resilience. Before selection, technical engineers should provide a complete list of the media, including main components, concentration fluctuation ranges, and whether intermittent cleaning agent residues are present, so that the supplier can recommend a gasket material accordingly; where necessary, options such as fluororubber or EPDM should be selected.
Confirm whether the plate material, gasket material, connection flange standard, design pressure, and temperature match the on-site piping; require the supplier to provide material certificates and pressure test reports, and pay attention to the influence of plate thickness and corrugation pattern on heat transfer efficiency. If any one of these parameters is missing, it may manifest as leakage or abnormal pressure drop after commissioning.
Procurement personnel should provide the supplier with medium corrosiveness, temperature and flow rate, allowable pressure drop, and installation and maintenance requirements all together, and have technical personnel complete the selection calculation; this can effectively reduce the risk of leakage and pressure drop after commissioning. The more complete the parameters provided, the smaller the deviation between the selection calculation and actual operating conditions.
Clamping dimensions exceeding the allowable range, additional stress in pipe connections, and failure to retighten gaskets to the specified torque after frequent disassembly and cleaning can all accelerate seal failure. Technical engineers should monitor the trend of clamping dimension changes in acceptance and maintenance records, and arrange replacement in advance when signs of gasket hardening are found.
