The heater core tube is the core pressure bearing heat exchange component of fluid heaters (water heaters, automotive warm air heaters, industrial heat exchange heaters). Laser welding leak proof connection refers to the use of laser continuous sealing welding between the core tube and the tube sheet/joint, replacing traditional argon arc welding, expansion welding, and brazing, to achieve leak free metallurgical bonding.
1. Sealing and leakage prevention (core function)
Form a continuous, dense, pore free, and seamless circumferential weld seam to achieve airtight and water tight sealing, preventing leakage of media (coolant, water, heat transfer oil) from the interface inside the pipe.
Prevent medium leakage from causing system pressure drop and heating failure;
Prevent coolant leakage from corroding surrounding electrical and metal components, and avoid short circuits and corrosion risks;
Prevent external air and water vapor from entering the tube in reverse, reduce oxidation and corrosion of the inner wall of the tube, and delay the aging and perforation of the core tube.
Traditional welding is prone to micro porosity and virtual welding, and the weld seam cracks and leaks slightly after alternating cold and heat; Laser welding has a continuous molten pool, reducing the probability of micro leakage, and can pass water pressure and air tightness tests.
2. Ensure structural strength, withstand cold and hot cycles and pressure fluctuations
The heat affected zone of laser welding is very small, the weld penetration is uniform, and the core tube mouth and tube plate form a metallurgical fusion joint.
The equipment starts and stops, and the temperature repeatedly rises and falls, resulting in thermal expansion and contraction stress, making the weld seam less prone to cracking and detachment;
Under the working conditions of water pressure impact and vibration, the fatigue resistance of the joint is better than that of simple expansion and brazing;
Thin walled core pipes are not easily deformed or bulged during welding, maintaining the accuracy of pipe opening dimensions and reducing stress concentration points.
3. Ensure stable heat exchange performance
The interface has no gaps, reducing contact thermal resistance and enabling efficient heat transfer; If there are gaps or looseness in the weld seam, it will form insulation gaps, reduce heat transfer efficiency, and the heating cannot reach the set temperature.
4. Enhance corrosion resistance and extend the lifespan of the entire machine
Laser welding has low heat input, and the metal around the weld seam is less prone to grain coarsening and chromium depletion, reducing the risk of electrochemical corrosion at the weld location. It is particularly suitable for stainless steel heater core tubes.
The weld seam has less oxidation and does not require extensive polishing, reducing the small damage points caused by polishing and lowering the source of corrosion leakage in the later stage.
5. Safety protection function
Liquid medium heater: prevent high-temperature medium from spraying out, avoid burns and equipment damage;
High pressure condition: To prevent pressure imbalance caused by medium leakage and protect the safe and stable operation of the entire heating system.
6. Advantages at the production level (from a product design perspective)
High welding consistency, suitable for mass automated production, reducing the after-sales failure rate of weld leakage after leaving the factory; Narrow welds, minimal deformation, stable assembly dimensions, and no impact on subsequent assembly.
