valco fittings
|
Valco Instruments Co. Inc. Sales:
800–367–8424
Fax: 713–688–8106
|
25
Unions
overall length of
zero volume union
is shorter than
zero dead volume union
because bore is remov
ed
more information
Reducing unions to
connect two tubes with
different ODs . . p 29-31
Unions with
1/4-28 fittings . . . . 72
Zero volume union
(through-bore union)
Zero dead volume union
(capillary bore union)
b
ore
tubing ends butt to one
another. the fitting is
slightly larger than the
tubing od.
tubing ID matches bore
of union
Zero Volume vs. Zero Dead Volume
tech tip
Through-bore
Union Installation
Because the tubing will
pass all the way through
a through-bore union, we
suggest making up the
first tube in a standard
Valco fitting to establish
the proper length of
tubing extending beyond
the ferrule. Install this
made-up connection in
the through-bore union;
then the second tube can
be butted against it for a
zero volume connection.
A true zero volume fitting is one in
which no part of the fitting actually
becomes a part of the flow path.
The only Valco fittings which fit this
description are our through-bore
unions, which allow tubing to butt
end-to-end. (So these are only zero
volume if the tube ends are perfectly
square.)
All other fittings are designed with
zero
dead
volume: that is, there is
no volume introduced by the fitting
which is not cleanly swept.
CHROMalytic TECHnology Pty Ltd AUSTRALIAN Distributors e-mail:
Tel: 03 9762 2034
