Style 689 is an expanded flexible graphite yarn reinforced with Inconel wire and fiberglass yarn. It also contains a sacrificial corrosion inhibitor.

Style 689 is available in the following cross-section range:
 1/8" to 1 1/2" (3.0 mm to 38.1 mm)

 
Applications
Style 689 is suitable for steam, water, oil, solvents, alkalis, acids, and most chemicals. Exceptions are oleum, fuming nitric acid, aqua regia, and fluorine.
Style 689 is recommended for both valve and some rotary applications. Typically, this packing should be used for high temperature valve and other static applications, as well as some rotary applications such as soot blowers.