138
VALVES
StainlessSteelSampleLoops
These high quality stainless steel sample loops have burr-free,
square-cut ends toensureaflush connection to valveports. The size
designations of loops are nominal. The actual volumes can differ
from the theoreticaldesignationsbecauseof the0.001” (±0.025mm)
toleranceof themetal tubingbore.
Accuracy of largemetal loops (1.0mm, 0.040”bore) is about ±5%,
intermediate loops (0.5mm, 0.020” bore) ±10%, and small loops
(0.2mm, 0.007”bore) ±30%.
Sinceboth standards andunknowns areusually analyzedusing the
samesample loop, knowledgeof theactual, accuratevolume is rarely
needed. Ifthesample loopvolumemustbeknown, it isbesttocalibrate
the loop inplaceon the valve so the flowpassages in the valve are
also taken into account. An alternative to calibration is touse adual
mode injector andpartial-fillingmethodof loading. See the“Sample
LoopLoading”ApplicationNoteonpage129.
Model 7725 Injector loopsarenot interchangeablewith loops for the
model 7125.Theportangle for the7725 is30°whereas theportangle
for the7125 is 20° requiring the loops tohaveadifferent shape.
Model 8125Micro-ScaleSample Injector requiresspecial loops in the
5.0µL to50µL range. The8125 sample loops aremadewith0.5mm
(0.020”)OD tubing.
APPLICATIONNOTE
How toProperly Install SampleLoops: Stainless Steel
Stainless steel sample loopsare suppliedwithfittings that arenot swaged
onto the tube. It is important that the loopbecompletelybottomed in the
injectorportbefore the ferrule is swagedonto the tube. Thedepthof the
tubingholesmayvary slightly fromport toport and fromvalve tovalve.
Afittingmadeup inoneportmay leavea small cavity inanotherport.
Thecavitycauseshighdispersionandpeakdistortion suchas fronting,
tailing, orbroadening. It isgoodpractice to label loopends so theywill
be replaced in the same, respectiveports thatwereused in swaging
the ferrules.Hint: swaging ferrules separatelyoneach side, intoeach
respectivevalveportmakes loop installationeasier.
To install the sample loop:
a) Takeoneendof the loopandplace thenut
(1) and ferrule (2) onto the tubing (3)with
the threadedportionof thenut and tapered
portionof the ferrule toward theend. See
FigureA.
b) Insert the tubing intoport (4).Confirm that
the tubing isbottomed in the valveport as
shown inFigureA.
c) Whilefirmlypressingdownon the tubing,
hand-tighten thenut as tight aspossible.
d) With the IDEXWrench (seepages33and144),
designedespecially for fittings, tightenone
quarter turnpast finger tight. Remove the loop
toconfirm the ferrule is swagedonto the tube.
e) Repeat stepsa-dwith theother endof the
loopwhile the swagedend remainsoutside
the valveport. SeeFigureB.
f) Reinstall eachendof the loop to their
respectiveports. SeeFigureC.
Figure1
Cut-away view
of stainless steel sample
loop installation
A
C
B
PartNo.
Volume
Tubing
RHEODYNE
®
STAINLESSSTEEL LOOPSFORMXT715-000
7755-300
5µLSample Loop
0.18mm (0.007”) ID x 1/16”OD
7755-301
10µLSample Loop
0.30mm (0.012”) ID x 1/16”OD
7755-302
20µLSample Loop
0.30mm (0.012”) ID x 1/16”OD
7755-303
50µLSample Loop
0.51mm (0.021”) ID x 1/16”OD
7755-304
100µLSample Loop
0.51mm (0.021”) ID x 1/16”OD
RHEODYNESTAINLESSSTEEL LOOPSFOR7125, 7010 INJECTIONVALVES
(DONOTUSEFOR7725)
7020
5µLSample Loop
0.18mm (0.007”) ID x 1/16”OD
7021
10µLSample Loop
0.30mm (0.012”) ID x 1/16”OD
7022
20µLSample Loop
0.51mm (0.020”) ID x 1/16”OD
7023
50µLSample Loop
0.51mm (0.020”) ID x 1/16”OD
7024
100µLSample Loop
0.51mm (0.020”) ID x 1/16”OD
7025
200µLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7026
500µLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7027
1.0mLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7028
2.0mLSample Loop
1.0mm (0.040”) ID x 1/16”OD
7029
5.0mLSample Loop
1.0mm (0.040”) ID x 1/16”OD
1876
10mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
1877
20mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
RHEODYNESTAINLESSSTEELLOOPSFOR3725-038,
3725I-038 INJECTIONVALVES
3065-018
2.0mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
3065-019
5.0mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
3065-023
10mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
3065-025
20mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
RHEODYNESTAINLESSSTEEL LOOPSFOR7725, 7725I, PR/EV700-100,
PR/EV703-100,MXMODULE INJECTIONVALVES (DONOTUSEFOR7125)
7755-020
5µLSample Loop
0.18mm (0.007”) ID x 1/16”OD
7755-021
10µLSample Loop
0.30mm (0.012”) ID x 1/16”OD
7755-022
20µLSample Loop
0.30mm (0.012”) ID x 1/16”OD
7755-023
50µLSample Loop
0.51mm (0.020”) ID x 1/16”OD
7755-024
100µLSample Loop
0.51mm (0.020”) ID x 1/16”OD
7755-025
200µLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7755-026
500µLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7755-027
1.0mLSample Loop
0.76mm (0.030”) ID x 1/16”OD
7755-028
2.0mLSample Loop
1.0mm (0.040”) ID x 1/16”OD
7755-029
5.0mLSample Loop
1.0mm (0.040”) ID x 1/16”OD
1876
10mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
1877
20mLSample Loop
2.0mm (0.080”) ID x 1/8”OD
RHEODYNESTAINLESSSTEEL LOOPSFOR8125 INJECTOR
(USE7755-024TO7755-029FORVOLUMES>50µL)
8020
5µLSample Loop
0.20mm (0.008”) ID x 0.020”OD
8021
10µLSample Loop
0.20mm (0.008”) ID x 0.020”OD
8022
20µLSample Loop
0.25mm (0.010”) ID x 0.020”OD
8023
50µLSample Loop
0.30mm (0.012”) ID x 0.020”OD
8125-084
Ferrules for 0.020” (0.5mm) Tubing
8125-086
Ferrules for 0.020” (0.5mm) Tubing, 4-pk
Seepage140 forValco-compatible stainless steel sample loops.
Sample Loops
