Metrohm 930 Compact IC Flex ChS/PP/Deg User Manual
Page 23
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3 Installation
930 Compact IC Flex ChS/PP/Deg (2.930.1360)
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15
Also see: PEEK pressure screws video on the Internet
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Connection capillaries
PEEK capillaries and PTFE capillaries are used in the IC system.
PEEK capillaries (poly-
etheretherketone)
PEEK capillaries are temperature-resistant up to 100 °C, stable under pres-
sure up to 400 bar (depending on the inner diameter), flexible, chemically
inert and have an extremely smooth surface. They can be readily cut down
to the desired length with the capillary cutter (6.2621.080).
Use:
￭
PEEK capillaries with an inner diameter of 0.25 mm (6.1831.010) for
the entire high-pressure section.
￭
PEEK capillaries with an inner diameter of 0.75 mm (6.1831.030) for
sample processing in the ultratrace range.
PTFE capillaries
(poly(tetrafluoroethy-
lene))
PTFE capillaries are transparent and enable visual tracing of the liquids to
be pumped. They are chemically inert, flexible and temperature-resistant
up to 80 °C. They can be readily cut down to the desired length with the
capillary cutter (6.2621.080).
Use:
PTFE capillaries (6.1803.0x0) are used for the low-pressure section.
￭
PTFE capillaries with an inner diameter of 0.5 mm for sample process-
ing.
￭
PTFE capillaries with an inner diameter of 0.97 mm for sample process-
ing and rinsing solutions (they are not necessarily included in the scope
of delivery of the instrument).
Capillary connections
NOTE
If you work with an increased system pressure (> 15 MPa), capillaries
may slip out of the pressure screws.
To avoid this, we recommend degreasing the ends of the capillaries
before installing them.
Dampen a cloth with acetone and wipe off the ends of the capillaries
before connecting them with the pressure screws.
In order to achieve optimum analysis results, capillary connections in an IC
system must be absolutely tight and free of dead volume. Dead volume
occurs if two capillary ends connected to each other do not fit exactly,
thus allowing liquid to escape. There are two possible causes for this: