The halogens are a series of elements that attack all forms of carbon and the passivated layer formed on the 300 series of stainless steel.

They include:

  • fluorine
  • bromine
  • chlorine
  • astatine
  • iodine.
  • Ununseptium may be a halogen

Although five of these halogens end in the letters “ine” it does not imply that all such words are halogens. Turpentine is not a halogen

When you choose seal materials for the sealing of halogens you should avoid carbon- graphite seal faces and black O-rings. Two hard faces would be a sensible choice and many O-ring compounds are available in a white color.

When making your choices remember we are talking about tank farm concentrations and not a little fluorine or chlorine in water.

See: Oxidizers that attack carbon, O023



  • On February 15, 2018