Vespel/graphite GC ferrules are made from quality polyimide/graphite blend. They seal with minimal torque and can be reused and repositioned along capillary columns if not over compressed in the fitting. Due to slight shrinking at high temperatures, they must be retightened after initial temperature cycles to avoid leaks.

• Trajan offers both Vespel/graphite blends, a 60/40 mix and an 85/15 mix
• The 85/15 maintains a high level of hardness and long lifetime
• The 60/40 blend is softer, with improved wear resistance and lower friction
• These ferrules will require less force to compress and form a seal

Two types of Vespel/graphite are commonly used, one with 40% graphite and one with 15% graphite. They are ideal for GC/MS interface applications because they are non-porous to oxygen. The inclusion of graphite increases high-temperature tolerance and reduces sticking and shrinkage.

Both blends have an upper temperature limit of 400 ℃.