general reference
VICIAG International
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103
Glossary
Detail
Seefittingdetail
.
Distributionfitting
Ageneric term for tees,crosses,andmanifolds,
used toprovidemultipleaccesspoints to
“distribute”agasor liquid througha system.
CAUTION!Usingadistributionfitting in reverse
tocoalescemultiple streamsmaycreatedead
volume.Specialmanifoldsareavailable for this
application.
F
FIA
Flow InjectionAnalysis.
A simpleandversatileanalytical technique
for automatingwet chemical analysesbased
on themanipulationof a samplezone formed
from the injectionof the sample intoa
continuous streamof fluidusedasacarrier.
Femalenut
Anutwith female threads;alsocalledexternal
nut.
Ferrule
Oneof thecomponentsof acompression
fitting; theconical pieceofmetal orplastic that
compressesonto the tubeas it is forced intoa
tapered seat.Valcometal ferrulesareunique
in that theyattach toand seal at the tubeby
cuttinga shallow ring into it, insteadofby
actually swaging it.This ispreferable since it
introducesnoflow restriction.
Filter
A typeof unionor reducingunionwhich
traps theparticulates ina stream.Thefiltering
element is typicallyamesh screenor sintered
frit.
Fingertightfitting
Afingertightfitting isaknurledorwinged
nutwhich ishand tightened tocompress the
ferrule.Note:Polymeric ferrules relyon surface
compression to forma seal andhold the tube
by friction.
Fittingdetail
Afittingdetail includes the thread toaccept
thenut,a tapered ferrule seat,and thepilot for
the tube. Thenut, ferrule,and tubego into the
fittingdetail tomake the seal.
Valcofittingdetailshave theperfect shape,
witha smooth transition from the ferrule seat
into thecylindrical and threadedpart.Many
otherfittingdetailsarepoor indesignwhere
the ferrule is forced ina too shallow ferrule seat.
The result isa“nicked”ferrulewhichcanno
longer apply its sealing force to the frontof the
ferrule.
Valcofittingdetail
Otherstyle
Flangedfitting
A typeof fittingusedwithfluoropolymer
tubing (PTFE,FEP) inwhichaflange ismade
at the tubeend.Connectionsaremadeat the
flangeeitherbycompressing theflange into
aflatdetail (typically1/4-28 threaded) orby
butting twoflanges together.A special flanging
tool forms theflanges.
Flangelessfitting
Similar inapplication to theflangedfitting,but
theflange isnot required.A ferrule system is
usedwhichgrips/compresses the tube.This
fitting typecanbeusedwithvirtuallyany
polymeric tubing since the tubeenddoes
nothave tobe formed,but simply squarecut.
Typicallyused in1/4-28 threadedfittings, it is
usually interchangeablewithflangedfittings.
Frit
Afilter element typicallymadeof stainless,
Hastelloy,Titanium,orpolymers,usually0.75
mmor 1mm thick.Fritsmayprovidebetter
filtration than screens,butbecause theyare
thicker there isgreatermixingpotential,and
they typically result in increasedpressuredrop.
