The softening of elastic gasket is related to pressure and temperature. When the gasket loses elasticity, the Plate heat exchanger will leak. In some products, in order to solve the leakage caused by the aging of the sealing gasket, it is allowed to adjust the sealing performance of the Plate Heat Exchanger, that is, re tightening the bolts of the combined plate Heat Exchanger, adjusting the compression force of the elastic sealing gasket between the heat exchangers to solve the leakage problem. The maximum and minimum allowable stresses are generally given on the nameplates of heat exchangers with this function. For the new heat exchanger, the minimum allowable stress should be used for connection and fixation. Depending on the number of heat exchanger plates in each group, the tightening force of heat exchanger can be adjusted once or several times. When tightening each time, the nut can be screwed in by 3mm, and the stress of the regulating plate should be paid attention to all the time during the tightening process. Moreover, only the heat exchanger without working pressure is allowed to adjust the tightening force at room temperature to prevent leakage.
For the plate heat exchanger whose stress adjustment range is not given in the name plate, the stress value is generally given in the part drawing. When tightening the plate heat exchanger, the tightening torque should not be lower than the value specified in the drawing, because it is related to the assembly quality and assembly deformation of the plate heat exchanger. When the tightening torque reaches the required value, the elastic gasket can be replaced in a planned way. For plate heat exchanger used in important production equipment and corrosive medium, it is recommended to have a set of spare seals. When the warehouse temperature is 18 ℃, the seal of plate heat exchanger can be kept for about 3 years in transparent plastic packaging.
