Reducing metal ion leaching
Maintaining optimal water quality with the right filler metals
Brazed components can unfortunately introduce metal ions to water, but Höganäs has discovered that using certain brazing filler metals can all but eliminate leaching issues in drinking water applications.
Regulations around acceptable metal ion content in drinking water vary from region to region, which you can see in this table. The NSF/ANSI 61 is applicable for USA and Canada.
|Cr||50 µg/L||50 µg/L||100 µg/L|
|Cu||2000 µg/L||2000 µg/L||1300 µg/L|
|Ni||20 µg/L||70 µg/L||100 µg/L|
|Mn||50 µg/L||-||300 µg/L|
There is a clear industry trend towards improving circularity and reducing environmental impact, which promotes the transition from Cu-brazed heat exchangers to Ni- or Fe-brazed ones. This has been the case even for applications where metal ion leaching behaviour or corrosion resistance technically allows use of Cu-brazed components.
Höganäs has tested the amount of metal ion leaching from various brazing filler metals that are relevant for drinking water applications, particularly for brazed plate heat exchangers. The tests highlighted that Höganäs’ iron-based brazing filler metals BrazeLet® F300-20 and BrazeLet® F86 offer significant technical advantages in terms of lower or no significant metal ion leaching to drinking water.
The conclusions from the tests enable Höganäs to make better material recommendations to existing and potential new customers. This deepened knowledge will also help Höganäs’ customers to meet the applicable regulations for metal ion leaching to drinking water in the markets they serve.
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Join our webinar "Brazing filler metals for low metal ion leaching in drinking water applications", and learn more about our findings that can all but eliminate leaching issues in drinking water applications.
Results in brief