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259
general reference
Glossary
external union
external reducing union
internal union
internal reducing union
E
External fitting:
a type of compression fitting in which the fitting
body has male threads; an external
nut
has female threads.
F
FIA:
Flow Injection Analysis. A simple and versatile analytical
technique for automating wet chemical analyses based on the
manipulation of a sample zone formed from the injection of
the sample into a continuous stream of fluid used as a carrier.
Ferrule:
one of the components of a compression fitting; the
conical piece of metal or plastic that compresses onto the
tube as it is forced into a tapered seat. Valco metal ferrules are
unique in that they attach to and seal at the tube by cutting
a shallow ring into it, instead of by actually swaging it. This is
preferable since it introduces no flow restriction.
Filter:
a type of union or reducing union which traps the
particulates in a stream. The filtering element is typically a
mesh screen or sintered frit.
Fitting detail:
one of the components of a compression fitting; if
the tube, nut, and ferrule comprise the male part of the fitting,
the fitting detail is the female part. It includes the threads for
the nut, the tapered ferrule seat, and the pilot.
Flanged fitting:
a type of fitting used with fluoropolymer
tubing (PTFE, FEP) in which a flange is made at the tube end.
Connections are made at the flange either by compressing the
flange into a flat detail (typically 1/4-28 threaded) or by butting
two flanges together. A special flanging tool forms the flanges.
Flangeless fitting:
similar in application to the flanged fitting,
but the flange is not required. A ferrule system is used which
grips/compresses the tube. This fitting type can be used with
virtually any polymeric tubing since the tube end does not
have to be formed, but simply square cut. Typically used in
1/4-28 threaded fittings, it is usually interchangeable with
flanged fittings.
Frit:
a filter element typically made of stainless, Hastelloy,Titanium,
or polymers, usually 0.75 mm or 1 mm thick. Frits may provide
better filtration than screens, but because they are thicker
there is greater mixing potential, and they typically result in
increased pressure drop.
G
GC:
Gas Chromatography. An analytical method incorporating
an injection system, analytical column, controlled temperature
zone, and detector. An inert carrier gas moves the sample
through the column, which separates the sample components
into discrete bands which are measured as they pass through
the detector.
Guard column:
a column used in series between the injector and
analytical column to prevent certain types of components from
entering the analytical column.
H
HPLC:
High Performance Liquid Chromatography. An analytical
system consisting of an injector, pump, analytical column, and
detector. Using a liquid mobile phase, the sample is pumped
through the column, where it is separated into discrete sample
component bands which are detected and measured as the
bands elute from the column.
I
ID:
internal diameter.
Inert:
technically, unreactive with other substances; however,
in the instrumentation field,“inert” is a relative term. Often
polymers are termed inert but are soluble in some fluids and
can react with some compounds.
Internal fitting:
a type of compression fitting in which the fitting
body has female threads; an internal
nut
has male threads.
L
LC:
Liquid Chromatography. Any of a variety of low to medium
pressure techniques which use a liquid mobile phase as the
carrier to move sample. Similar to HPLC.
Large bore:
a bore that is larger than the standard for a given
fitting; a fitting ordered with a large bore will have a larger flow
orifice than the standard or capillary bore fitting of the same
design. Denoted by suffix “L” in the product number.
Luer adapter:
an adapter that connects a tapered luer fitting
(square nib) of a syringe to a tube or tube fitting.
CHROMalytic TECHnology Pty Ltd AUSTRALIAN Distributors e-mail:
Tel: 03 9762 2034
