The most intuitive indication of leakage in the refrigeration dryer is that the refrigerant pressure gauge is zero. The first step in fluorine leakage is to find the leak point. First, use visual inspection to open the machine box and observe the inside of the machine. As the refrigerant is running, there will be compressor lubricating oil mixed inside. If there is a leakage of Freon, the lubricating oil will be taken out. Then, carefully observe the inside of the machine. If there are flake like oil stains, it is likely that the leak point is located. Then, check the capillary copper pipes inside the machine, that is, those thin copper pipes and process pipes below 6mm, for any breakage. After passing the basic inspection mentioned above, mark any suspicious areas. Next, it is necessary to confirm the leak point by adding a certain pressure of inert gas. If conditions permit, it is best to use nitrogen to maintain pressure. Without nitrogen, gaseous Freon can also be used. It is strictly prohibited to use oxygen to maintain pressure and check for leaks. When maintaining pressure, slowly add gas and observe the pressure on the refrigerant gauge of the cold drying machine while applying pressure (small cubic meters only have low pressure gauges for refrigerant, and 15 cubic meters and above have high and low pressure gauges). Stop when the pressure reaches around 0.2Mpa, and then carefully listen for any sound of air leakage inside the machine. The place where the sound is emitted is the leakage point. If not, continue to pressurize to 0.5Mpa and stop. At this point, dip a sponge in soapy water, check the suspected area earlier, and then check all connecting pipes (copper nuts) inside the machine. If there are any leaks, there will be bubbles. If the leakage point is still not found through the above methods, it is very likely that there is internal leakage in the evaporator. At this point, the evaporator and refrigeration system should be disconnected first, and then the pressure should be separately maintained to confirm. If the pressure drops after separate pressure maintenance, it is found that there is internal leakage in the evaporator. Another relatively simple method is to open the inlet of compressed air. If the pressure of the refrigerant pressure gauge rises after a period of time, it can be confirmed that the refrigeration system is connected to the air system and there is internal leakage in the evaporator.

After detecting the leakage points, it is time to make up for them. For loose bell mouth leaks, only use a wrench to tighten them accordingly. If it is a copper pipe welding type leak, brazing is required. Brazing is one of the most commonly used skills in the refrigeration and maintenance industry. Brazing is the method of using oxygen and acetylene flames to heat the low silver welding rod and the required repair welding area, allowing the welding rod and repair welding area to melt together and block the leakage point. When brazing, the pressure of the refrigeration system should be released to zero first, and then the brazing gun should be used to open acetylene first. After ignition, oxygen should be added appropriately, and the ratio of oxygen and acetylene should be slowly adjusted to make the flame a neutral flame - an oxide flame. Then, the required welding area and silver electrode should be heated to dissolve the two together. After handling the leakage points, it is necessary to maintain pressure on the system again to confirm whether the repair welding is successful.

After completing the leak repair, it is necessary to vacuum the system and add the specified mass of liquid Freon. The refrigerant should be added from the needle valve reserved for the cold dryer. For larger machines, fluorine should be added first from the high-pressure filling port. If the specified dose cannot be added at once, slowly add it from the low-pressure port to the specified dose after starting the machine