valco valves
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99
About Two Position Injectors and Switching Valves
more information
Actuation
. pp 186-209
Applications
. 117-121
Materials
Metals . . . . 254-255
Polymers . . . . . .256
Valve rotors . . . . 257
Valve descriptions
Cheminert
injectors . . 144-149
Cheminert
selectors 144, 150-151
Diaphragm . . . . 140-141
Valco
selectors . . 100-101
Valco valve prices
GC . . . . . . 102-111
HPLC . . . . . 112-116
Selectors . . . 122-133
Two position injectors and switching valves have many applications, as shown
in the section beginning on page 117. In this catalog, Valco two position valves
are divided into GC and HPLC sections, with the GC section starting on page 102
and the HPLC section on page 112.
Sample Injectors
Since the most common method
of sample injection utilizes a 6 port
valve with an external sample loop,
6 port valves are often referred
to as “injectors”. However, as the
Applications section shows, 6 port
valves can do more than inject sample,
and 8 and 10 port valves can be
sample injectors at the same time
they’re also being backflushers or
column switchers. One more variation
is the 4 port internal sampling valve
(pages 102–103 and 112), which is
used when the sample size must be
smaller than the smallest available
loop. The internal sample “loop” is
actually an engraved connecting slot
on the rotor which is sized to contain a
specified amount of sample.
Sample Loops
Loops are electrolytically cut and
electrochemically polished to ensure
square, burr-free ends, then cleaned
with microfiltered steam from
deionized water. Standard material
is Type 316 stainless, but loops can
be supplied in electroformed nickel,
Hastelloy C, Nickel 200, titanium, or
several polymers. Consult the factory
for availability.
Valco sample loops are accurately
sized for each valve type. The volume
tolerance matches the ID tolerance of
the tubing, which is typically ±0.001".
This results in a variance ranging from
30% with tubing of 0.005" diameter to
5% for loops made from tubing 0.040"
in diameter.
specifications
valco two positionvalves
Valve
Standard
Max
Max
Max
Max
type
rotor
pressure temp pressure temp
material
Internal
Sampling and
sample injectors
switching valves
GC
W and UW Valcon E 1000 psi liq 175°C 400 psi gas 225°C
Valcon T –
– 300 psi gas 330°C
MW Valcon E2 –
– 100 psi gas 75°C
HPLC
W and UW Valcon H 5000 psi liq 75°C 5000 psi liq 75°C
valve types
Fitting Standard
size port diameter
W Type 1/32" 0.25 mm (.010")
1/16" 0.40 mm (.016")
UW Type 1/16" 0.75 mm (.030")
1/8" 0.75 mm (.030")
MW Type 1/4" 4.0 mm (.156")
For special port diameters,
please consult the factory.
optional rotors
Valcon M 400 psi
50°C
Valcon P 400 psi
175°C
Valcon R 400 psi
75°C
Valcon TF 200 psi
50°C
See page 257 for a discussion of
these optional rotor materials.
CHROMalytic TECHnology Pty Ltd AUSTRALIAN Distributors e-mail:
Tel: 03 9762 2034
