1, soap bubble leak detection

First cut the soap into thin slices, dipped in warm water, so that it dissolves into a thick soap solution. When leak detection, wipe off the stain with gauze on the inspected part, dip a clean brush into the soap solution, wipe it evenly around the inspected part, and carefully observe whether there are bubbles, such as the appearance of soap bubbles, indicating that there is a leak there. Sometimes, it is necessary to fill the system with 0.8-1.0Mpa (8-10kgf/cm2) of nitrogen gas first.

2、Leak detection in water

This method is often used in the compressor (note that the terminals should be waterproof protection), evaporator, condenser and other parts of the leak detection. The method is: the evaporator should be filled with 0.8Mpa nitrogen, the condenser should be filled with 1.9MPa nitrogen (for heat pump type air conditioners, both should be filled with 1.9MP nitrogen), immersed in about 50 degrees of warm water, carefully observe the occurrence of bubbles. The purpose of using warm water is to reduce the surface tension of water, because the lower the temperature of water, the greater the surface tension, tiny leaks can not be detected. The leak detection site should be well lit and the water surface is calm. The observation time should be not less than 30 seconds, and the workpiece should preferably be immersed below 20 cm into the water surface. The parts should be dried and processed after water leak detection before welding.

3、Leak detection by pressure filling

After the refrigeration system has been repaired and welded, before charging the refrigerant, it is better to charge 1.5Mpa nitrogen and close the three-way service valve (the valve itself cannot leak) near the end of the day. To go to work the next day, if the gauge pressure does not drop, it means that the repaired refrigeration system is not leaking. If the gauge pressure drops, it means there is a leak, and then use the soap bubble leak detection method to detect leaks.

4、Leak detection by hand touching oil stain

The refrigerant of the air conditioner is mostly R22, R22 and refrigeration oil have a certain mutual solubility, when R22 has a leak, refrigeration will also seep out or drip out. Using this characteristic, we can determine whether there is a leak by visual inspection or by touching the oil. When the leak is less, when touching with fingers is not obvious, you can wear white gloves or white paper to contact the suspicious place, can also find the leak.

5, halogen lamp leak detection

Flame color change from light green → dark green → purple, the amount of leakage from micro-leakage → serious leakage.

6、Leak detection by electronic leak detector

The main parts of the leak detection are: the welding of the suction and discharge pipes of the compressor; the small elbow of the evaporator and condenser, the inlet and outlet pipes and the welding parts of the branch pipes: such as the filter drier, the shut-off valve, the solenoid valve, the thermal expansion valve, the distributor, the connection of the liquid storage tank, etc. The difference between leakage and blockage judgment: leak repair, vacuum, re-infusion of refrigerant, the air conditioner can restore the cooling effect; if it is blocked, even if fluoride, the air conditioner still can not be cooled, the pressure is not normal.

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