The main manifestations are leakage (large volume, continuous water droplets) and leakage (small volume, discontinuous water droplets). The main places where leakage occurs are the seal between the plate and the plate, the two sealing leakage grooves of the plate, and the inner side of the end plate and the compression plate.

Abnormal pressure and temperature will appear in the system. The main feature is that the medium on the higher pressure side is strung into the medium on the lower pressure side. If the medium is corrosive, it may also cause corrosion of the gasket of the plate heat exchanger. Liquid leakage usually occurs in the diversion area or the secondary sealing area.

Even many times higher than the design value, the medium inlet and outlet pressure drops exceed the design requirements, which seriously affects the system's requirements for flow and temperature. If the pressure drop on the hot side is too large, in the heating system, the primary side flow will be seriously insufficient, resulting in the secondary side outlet temperature that cannot meet the requirements, that is, the heat source is insufficient.

The main feature is that the outlet temperature is low, which fails to meet the design requirements.