valco valves
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Valco Instruments Co. Inc. Sales:
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These illustrations show basic sample injection techniques
using Valco two position valves. With rare exceptions, there
is no difference between switching valves and external
volume sampling valves, so the same valve can be used
for either function.
The unique advantage of 8 and 10 port valves is that
they reduce extra column volume by combining sampling
and switching functions in a single valve. This minimizes
expense, maintenance, service, and risk of leaks as
compared to multiple 6 port valve systems.
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Microvolume Sample Injection
The internal sample (fixed volume)
flowpath is used when very small sample
volumes are required. The sample size is
determined by a passage engraved on the
valve rotor, allowing precise, repeatable
injections. In Position A, the sample
flows through the sample passage while
the mobile phase flows through to the
column. The third passage is inactive. In
Position B, the sample passage is in line
with the column and the mobile phase
injects the contents of the sample passage
onto the column.The passage which was
inactive in Position A allows the sample to
continue flowing without interruption.
Dual Microvolume sample
Injection
This microvolume injector can be used to
alternate between two different samples.
Each time the valve is switched, a sample
is injected. By connecting the two sample
inlets in series, the valve injects the sample
each time the valve switches. This is
particularly useful in heavy duty cycle
operations to minimize valve wear. The
valve can also be used to make alternating
injections of the same sample onto two
different columns by swapping sample/
waste and pump/column connections.
Note:
This C
I
6 valve is not shown
in this catalog. Call for details.
Two Position Applications
6 port internal sample injector
4 port internal sample injector
CHROMalytic TECHnology Pty Ltd AUSTRALIAN Distributors e-mail:
Tel: 03 9762 2034
