The term “Vespel” at 0:38 is used to describe the Graphite/Vespel ferrules composed of a 15% graphite and 85% polyimide material. This is a common misnomer for this ferrule because Vespel is the trade name for polyamide. Please note that the third type of ferrule is the combined graphite Vespel ferrule, which is used for oxygen sensitive detectors such as the mass spectrometry or electron capture detector.
Which Ferrule Should I Use on My GC?
Ferrules and connectors for GC allow end users to fully customize their instrument and flow-path to meet their unique analytical needs. Minor leaks within the sample flow path can be detrimental to instrument performance, resulting in variable retention times, elevated background noise, column bleed, tailing peaks, and inlet discrimination.
- Low temperature, isothermal applications up to 280 °C.
- Can be re-used or removed easily.
- Graphite capillary ferrules offer limited thermal expansion or contraction.
- Capable of withstanding inlet/oven temperatures up to 450 °C.
- Recommended for high-temperature applications exceeding 350 °C.
- Not recommended for use with oxygen-sensitive columns or detectors such as MSD or µECD.
- Composed of a 15% graphite and 85% polyimide material by weight.
- Recommended for oven temperatures up to 350 °C.
As a note, the long ferrules should be used with the brass nut and winged collar nut. The short ferrule can be used with the self-tightening nut. Using the self-tightening nut on both the inlet and MSD makes stocking supplies easier because the same ferrule is used for both.
Flexible Metal Ferrules
- Composed of stainless steel and coated to ensure complete inertness.
- Each sized flexible metal ferrule is uniquely designed to prevent inventory mix-ups.
- For inert inlet and detector connections use UltiMetal Plus coated ferrules.
- Gold-plated ferrules are designed for Capillary Flow Technology (CFT) devices
- Don’t use gold-plated flexible metal ferrules on your inlet or detector as they could fuse with the components found inside each.
GC Ferrule Selector Tool
For more assistance selecting the correct ferrule for your application, try the Agilent GC Ferrule Selector Tool. The tool will ask you simple questions about your application, oven temperature, detector type, and column size to determine the correct and most recommended ferrule for your application. At the end, you’ll be presented with a specific part number ready to order.