Ferrules Manufacturing Capabilities


image of various ferrule groups


CRS manufactures a wide variety of standard and special ferrules and seals used in gas chromatographs and other instruments. The commonly used materials are Dupont Vespel, PTFE, and Exfoliated Graphite.

Engineers at CRS are able to take special design requirements for precision ferrules, including applications requiring high temperature and ultra-clean environments, and provide design input, samples and finished product.

The standard ferrule product line is used to seal tubing and capillaries to standard compression fittings in a variety of sizes. At CRS we frequently manage requests for similar special applications. General material selection guidelines can be drawn from the standard product line outlined below.

Useful design data can be found for Vespel products at Dupont Design Guides (see especially the “S” grades), and for PTFE at Chemours PTFE Specification.


CRS provides a wide range of ferrules made from Vespel®, Vespel/Graphite, Graphite and PTFE.



Vespel® Ferrules (SP-1):

They are made from high temperature Dupont polyimide, a hard polymeric material that tends to seal permanently to capillary columns when in use. They are not re-useable.


Vespel®/Graphite Ferrules (SP-21 and SP-22):

They are made from DuPont polyimide/graphite blended compounds. They are ideal for GC/MS interface applications because they are non-porous to oxygen. They seal with minimal torque and are not re-usable. Due to slight shrinking at high temperatures, they must be retightened after initial temperature cycles to avoid leaks. Two types of Vespel/Graphite are commonly used, one with 40% graphite and one with 15% graphite.


Graphite Ferrules:

They are made from high-purity exfoliated graphite. They seal with minimal torque and can frequently be re-used. They do not shrink in use, but they are very soft and must be packed and handled carefully.


PTFE Ferrules:

They are made from 100% PTFE. They are soft and completely inert. PTFE ferrules are commonly used in liquid applications.


CRS Cares:

Our attentiveness to our customers results in chromatography accessories that set new levels of value. At CRS, value is defined by quality products, technical support, guaranteed performance, and customer satisfaction.




Please give us a call today at 502.491.6300 with any questions you may have!


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