Halogen-free

From GAWDAwiki

Halogen-free is a desired term in welding, typically relating to products, chemicals and processes that do not contain fluorine, bromine, iodine, astatine and the other “halogen” element chlorines. This relates to avoidance of contamination of materials and welds - especially in halogen-(chemical)-sensitive industries, such as nuclear, bio-research, pharmaceutical, semi-conductor, food, dairy, aerospace, etc. Halogen contamination (i.e., from standard masking tapes - chlorine is present in the adhesive) can lead to embrittlement of austenitic stainless steel and titanium alloys. Halogen-free tapes need to be used to preseal root gaps, outlets and pipe ends when purging with inert gas, prior to welding.^[1]

References

1. Dave Dunbar, Intercon Enterprises Inc.