Copper tube welding techniques and methods; first, use gas flame to implement uniform heating of the joints, and then use the brazing material to contact the joints heated to a high temperature, determine the temperature of the joints, and then continue to heat the joints while adding brazing material to the joints of the gap, and finally removed from the heat source, stop heating, so that the joints in the static state of cooling and crystallization.

First, how to weld copper pipe?

1、Pre-preparation

(1) will be the outer surface of the copper pipe joints and fittings joints at the inner surface of the oxide film cleaned up. In the cleaned tube outer surface and the inner surface of the fittings uniformly brushed paste or liquid brazing agent, using copper-phosphorus brazing material or low-silver copper-phosphorus brazing material brazing copper and copper pipe fittings, may not be coated with brazing agent.

(2) Insert the copper tube into the pipe fittings, insert it to the bottom and rotate it appropriately in order to maintain an even gap, if it is coated with brazing flux, the excess brazing flux extruding out of the joints should be wiped away with a clean rag.

2、Soldering copper pipe

(1) Use gas flame to implement uniform heating of the joint until it is heated to the brazing temperature, tin brazing, electric heating can also be used to heat the joint to the brazing temperature.

(2) Use brazing material to contact the joint which is heated to high temperature to determine the temperature of the joint, if the brazing material does not melt, it means that the temperature of the joint has not yet reached the brazing temperature, and it is necessary to continue to heat the joint.

(3) If the brazing material can be melted quickly, it means that the temperature of the joint has reached the brazing temperature, and you can continue to heat the joint to keep the temperature of the joint above the brazing temperature, and add the brazing material to the gap of the joint, and melt the brazing material into the gap by using the heat of the joint until the brazing gap is full, and do not melt the brazing material directly with the flame and apply it to the surface of the gap.

3、Cooling

Remove the heat source, stop heating, so that the joint in a stationary state cooling crystallization, to prevent the molten brazing material cooling crystallization by vibration and affect the brazing quality. Clean up the residue at the brazed joints, and brush on varnish for protection if necessary.

Second, what are the precautions for copper pipe welding?

1, welding to wait for the solder solidified before moving the copper tube, otherwise the welding part will crack. Welding should wait for the refrigerant discharge before proceeding, otherwise the refrigerant will produce toxic phosgene when encountering open flame, these phosgene is harmful to human body.

2, copper pipe welding requires the use of gas flame, gas cylinders should be placed upright, the distance from the open flame is greater than 5 meters, in order to avoid fire accidents, welding torch and gas cylinders should be connected in a correct manner.

3, in the copper pipe welding, to be in the ventilation of a good state of the place for construction, construction personnel need to wear good professional protective glasses, welding site to have fire extinguishing equipment.