Brazing filler metals for low metal ion leaching in drinking water applications
The quality of drinking water is affected by metal ions introduced through leaching from materials that come in contact with it, such as pipes, fittings and heat exchangers. Regulatory authorities have established maximum permissible quantities of metal ions in drinking water. In brazed components, the leaching of metal ions can be observed due to the interaction of both the base material and the brazing filler metal in contact with the water. With the correct selection of base material and brazing filler metal this effect can be minimized. The metal ion leaching of AISI 316L components brazed with different filler metals, Cu-foil (99.9% Cu), BNi-5, BrazeLet® Ni613, BrazeLet F300-20 and BrazeLet F86, was investigated and compared to suggest the best choice for minimizing the amount of metal ions leached into the water.