Harm of unprotected welding: When there is not enough nitrogen filling in the cold medium pipeline being welded during brazing, oxide will be produced on the inner surface of copper pipe, which will cause blockage of refrigerant system, deterioration of compressor lubricant, burnout of compressor, poor air conditioning effect and other faults. In order to avoid these problems, nitrogen must be continuously flowed into the refrigerant pipe during brazing, and ensure that nitrogen flow passes through the operating solder joint until the copper pipe is completely cooled at the end of the welding. Nitrogen pressure should not be too high, otherwise it is easy to cause bubbles and trachoma in solder joints and even can not be welded.

Practice of Nitrogen Filling Pipe Joints of Air Conditioning Copper Pipe Manufacturers:
When welding pipe parts, please connect the nitrogen-filled pipe joint with the welded pipe parts.

1. Notices in Welding Pipe Parts
Transition tube is used, and trumpet butting is strictly prohibited. Nitrogen filling from the side of the short tube has short distance and good nitrogen replacement effect.

2. Standard operating points of brazing operation:
Nitrogen pressure is controlled between 0.2 and 0.3 kgf/cm2 during welding. The use of gases must be nitrogen. The use of flammable and combustion-supporting gases such as oxygen is prohibited in order to avoid explosion danger. Pressure relief valves must be used and nitrogen pressure should be controlled at 0.2kgf/cm2. Select the appropriate nitrogen inflow position. Ensure that the nitrogen path flows through the operating solder joints. When the pipeline between the nitrogen inlet position and the solder joint is long, ensure sufficient nitrogen inlet time to ensure that the oxygen in the welding position is completely discharged. Nitrogen is continuously introduced after welding until the pipeline is completely cooled. Welding work should be carried out downward or horizontally laterally, avoiding inverted welding as far as possible.

Attention should be paid to fire prevention during welding operation (preparation of fire fighting equipment).

Be careful not to burn. Pay attention to the fit clearance of pipe socket connection.