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99
AboutTwoPosition Injectors andSwitchingValves
more information
Actuation
. pp186-209
Applications
. 117-121
Materials
Metals . . . . 254-255
Polymers . . . . . .256
Valve rotors . . . . 257
Valvedescriptions
Cheminert
injectors . . 144-149
Cheminert
selectors 144,150-151
Diaphragm . . . . 140-141
Valco
selectors . . 100-101
Valcovalveprices
GC . . . . . . 102-111
HPLC . . . . . 112-116
Selectors . . . 122-133
Twoposition injectorsand switchingvalveshavemanyapplications,as shown
in the sectionbeginningonpage117. In this catalog,Valco twopositionvalves
aredivided intoGCandHPLC sections,with theGC section startingonpage102
and theHPLC sectiononpage112.
Sample Injectors
Since themost commonmethod
of sample injectionutilizesa6port
valvewithanexternal sample loop,
6port valvesareoften referred
toas“injectors”. However,as the
Applications section shows,6port
valves candomore than inject sample,
and8and10port valves canbe
sample injectorsat the same time
they’realsobeingbackflushersor
column switchers. Onemorevariation
is the4port internal samplingvalve
(pages102–103and112),which is
usedwhen the sample sizemustbe
smaller than the smallest available
loop. The internal sample“loop”is
actuallyanengravedconnecting slot
on the rotorwhich is sized tocontaina
specifiedamountof sample.
SampleLoops
Loopsareelectrolyticallycut and
electrochemicallypolished toensure
square,burr-freeends, thencleaned
withmicrofiltered steam from
deionizedwater. Standardmaterial
isType316 stainless,but loops can
be supplied inelectroformednickel,
HastelloyC,Nickel 200, titanium,or
several polymers. Consult the factory
for availability.
Valco sample loopsareaccurately
sized for eachvalve type. Thevolume
tolerancematches the ID toleranceof
the tubing,which is typically±0.001".
This results inavariance ranging from
30%with tubingof 0.005"diameter to
5% for loopsmade from tubing0.040"
indiameter.
specifications
valcotwopositionvalves
Valve
Standard
Max
Max
Max
Max
type
rotor
pressure temp pressure temp
material
Internal
Samplingand
sample injectors
switchingvalves
GC
WandUW ValconE 1000psi liq 175°C 400psi gas 225°C
ValconT –
– 300psi gas 330°C
MW ValconE2 –
– 100psi gas 75°C
HPLC
WandUW ValconH 5000psi liq 75°C 5000psi liq 75°C
valvetypes
Fitting Standard
size portdiameter
WType 1/32" 0.25mm (.010")
1/16" 0.40mm (.016")
UWType 1/16" 0.75mm (.030")
1/8" 0.75mm (.030")
MWType 1/4" 4.0 mm (.156")
For special portdiameters,
pleaseconsult the factory.
optionalrotors
ValconM 400psi
50°C
ValconP 400psi
175°C
ValconR 400psi
75°C
ValconTF 200psi
50°C
Seepage257 for adiscussionof
theseoptional rotormaterials.
CHROMalyticTECHnologyPtyLtdAUSTRALIANDistributors e-mail:
: 03 97622034
