The FSR adapter is the only adapter recommended for use in valves. It consists of a liner which slides over the fused silica tubing and a ferrule which makes up on the liner. The liner has an enlarged diameter at one end which is captured by the nut, so the liner and the tube within it are removed as the nut is unscrewed from the valve.

Two piece fused silica adapters are available in Valcon polyimide for use up to 350°C; 1/16" adapters are also available in PEEK for lower temperature applications (up to 175°C).

Valcon polyimide is a unique graphite-reinforced composite, specially prepared to maximize mechanical stability at high temperatures. Small blocks are subjected to extreme loads by a process known as hot isostatic pressing, with individual ferrules subsequently machined from these blocks. The result of this two-step process is a fused silica adapter with high temperature stability which far exceeds that of parts produced by conventional molding.

Notes:
The determining factor in selecting the adapter size is the fused silica tubing's outer diameter, or OD.
The 1/16" FSR adapter includes a special counterbored 1/16" nut.