valco fittings
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VICI AG International Sales: + 41–41–925–6200 Fax: + 41–41–925–6201
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Valco Fittings
The two piece compression fitting (
Figure 1
), in which a ferrule is compressed
onto the tube as a nut is tightened, offers reliability in high pressure situations
and in connecting metal tubing. Valco excels in all critical areas of the design
and manufacture of such fittings. Quality considerations, which cannot be
ignored if an analytical system is to reach and maintain optimum performance
levels, include interchangeability, counterbore tolerances, ID/OD concentricity,
mixing potential, cleaning procedures, and the method employed to“make up”
the ferrule on the tube.
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Figure 1
Valco compression fitting
No Tubing Deformation
The basic concept of compression
fittings carries the inherent danger of
tube deformation (
Figure 2
). While
some manufacturers emphasize this
positively as a method of ensuring
that the tubing doesn’t blow out of the
ferrule, the flow anomalies introduced
by the restricted ID make these fittings
a poor choice for many instrument
applications.
tech tip
For optimal zero dead
volume connections,
make sure your tubing
meets the best industry
standards—OD tolerance
should be nominal
dimension ± .002".
Fractional
Nominal
dimension dimension
1/32"
.031
1/16"
.062
1/8"
.125
1/4"
.250
3/8"
.375
1/2"
.500
caution!
The analytical devices
market has attracted
numerous companies
which copy Valco/
Cheminert designs.
Please exercise caution in
the use of copies, which
may not be compatible
with the original versions
in this catalog.
Because of VICI’s high
volume production and
dedicated machinery,
our fittings are often
less expensive and of
consistently higher
quality than competing
copies.
Valco metal ferrules cut a ring near
the end of the tube (
Figure 3
), which
prevents tube release at high press-
ures without significantly deforming
and restricting the tube interior.
Because our ferrules have a sharp edge
at the ID near the nose, this usually
takes only about 1/4 turn beyond the
point where the ferrule first starts to
grab the tubing. There is so little tube
distortion that they are routinely used
with glass-lined tubing! Only Valco’s
polymer fittings rely on friction to hold
a tube.
CHROMalytic TECHnology Pty Ltd AUSTRALIAN Distributors e-mail:
Tel: 03 9762 2034
