Refrigerant leakage in high and low temperature test chambers often occurs in copper and aluminum joints. There are four commonly used welding methods for maintenance personnel only.
1. Copper-aluminum joint adhesive bonding method. In the high and low temperature test chamber copper and aluminum joints are not broken, coated with sandpaper and coated with double glue (SA101, SA102, SA103, SA104 metal universal glue, etc.), after the glue is dried and solidified, it can be used. Therefore, the law is simple and economical, so it is widely used.
Second, copper and aluminum direct welding method. First expand the aluminum tube, sand the copper tube with sandpaper, apply aluminum flux on the surface, insert the copper tube into the expanded aluminum tube and turn it a few times, then heat it with a gas torch (focus on heating the copper tube side) Copper and aluminum are welded together. However, this method is not easy to weld.
Third, in the high and low temperature test box copper tube after the tin and then the glue method. In order to prevent the occurrence of patina, the joint (do not break) the copper tube to rust and polish the flux and apply a layer of tin (the tin area is larger than the adhesive area) to prevent green rust and not leak.
Fourth, aluminum copper plating, soldering method. The aluminum tube is expanded, sanded with sandpaper, immersed in a copper sulfate solution, and the special aluminum tube is plated with copper and then soldered.
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