1. Check all sealing surfaces welds of plate heat exchanger frequently to see if there is any abnormal phenomenon such as leakage. If leakage is found, mark the leakage place in time, deal with it after the plate heat exchanger is shut down.

　　2. The pressure gauge thermometer of plate heat exchanger shall be checked regularly to see if there is any abnormal phenomenon.

　　3. When the plate heat exchanger stops, slowly close the inlet valves of hot cold media, then close the outlet valves of the two media. On the contrary, open the outlet valve first, then slowly open the inlet valve.

　　4. The medium at the low-pressure side shall be tested regularly to avoid mixing of medium at the high-pressure side. If there is any mixing, it indicates that there is internal leakage, the plate heat exchanger shall be shut down for treatment.