more ABOUT FERRULES 2014+ FlipPAGE5 Price List 2016; (PDF)
Ferrules as used in the Chromtechs’ context . . .
Are leak-tight Pipe-fitting seals connecting Tube Fittings and various type of Tubing; SS, polymeric, glass ceramic , fused silica . . . in capillary and larger GC Column sizes; the latter being “fragile” and will just not sustain compression by conventional metal ferrules ( “a la” Swagelok etc )
Metal ferrules normally used by “Fittings OEMs” traditionally use metal (SS/Brass)
And with their obvious limitations !
It’s not even in their pecuniary interest to even make OR re-sell Graphite Ferrules
Metal Once-off use - then you’re /they’re “buggared” !
Graphite Ferrules “slide-off” can be re-used many times
altho’ they do tend to be “captured’ in the Nut if over-tightened
> For some GC OEMs with fore-sight ( eg Fison / Shimadzu) specify metal-jacketed/sleeve versions & in specially designed fittings > ASK !
Applications include chromatography connections where gas-tight seals are essential both in positive pressure but also under high Vacuum such as GC/MS where the material used must be high purity and sustainable at up to 450degC nowadays
Common sizes range from (1/32, 1/16, 1/8, 1/4”OD with IDs tube size
as small as 0.3mm up to 2.0”ID and larger for more exotic applications ? ASK!
AS far as we know we are the ONLY OEM of GFs with IDs larger than 1/2”
. . . ANYWHERE !
In fact there are few OEMs who make GFS at all . Most Suppliers are in fact Distributors ONLY ( such as Agilent, Thermo, Shimadzu etc and AT MANY TIMES THE PRICE
Graphite Ferrules see Graphite Ferrules (HTM)
> by FAR are the most Universally applicable type !
& where the Metal Ferrules are just NOT Good Enough !
FITTINGS OEMs DON’T necessarily like us > as GFs are reusable (with care) and easily slide off the tubing;
They are soft and malleable and deform to fit the shape of the fittings “internals” . . . and help to reduce dead-volume
They also have similar co-effs of thermal expansion as metal and will not leak under temperature cycling
There are virtually NO practical temperaure limits (but >450C as constraints impose by current Gas Chromatography practices and up to 1800C in an inert atmosphere)
Pressure Limits are at customers discretion
( Straight>> Reducing Type ) >100s psig size gas dependant
DONT USE with Hydrogen/Oxygen Air/ at High Temp >300c ?