
V9-8 MANU AL AND AV9-8 AUTOMATED
STREAM SELECT VALVES
CATALOG NUMBERS 750-0403 AND 750-0408
The Model V9-8 and Model AV9-8 Stream Select Valves are high pressure, 9-port, 8-position valves for stream
selection. The valves are rated at 1000 psi (max.). The 8 ports (labeled 1 through 8) provide bi-directional fluid
flow. The ninth port is the central common port located at the base of the valve. The fluid pathway is chosen
either by manually turning the valve arm on the Model V9-8 until the port indicator window shows the desired
port or by initiating a command from the Controller to the Model AV9-8. Note that for the AV9-8 the default
position at system power up or at the conclusion of a run, is position 1 (Ports 1 and 9 connected). Refer to the
BioLogic Instruction Manual for discussion of software control of the valve.
Connection to the BioLogic Rack and Workstation
Model V9-8 and AV9-8 Stream Select Valves mount to the Rack using the supplied bar and clamp. An Allen
wrench is included to secure the clamp and valve to the rack.
The Model AV9-8 Automated Stream Select Valve is powered and controlled by the Bio-Logic Workstation.
Connect the signal cable for this valve to any of the connectors labeled Automated Valves, connectors 4, 5 or 6.
The Model V9-8 Manual Stream Select Valve is not connected electrically to the BioLogic System.
Bio-Rad Laboratories, 2000 Alfred Nobel Drive, Hercules CA 94547 • Phone (510) 741-1000
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8
7
1
COMMON
2
5
3
4
3
V9-8 MANUAL
STREAM SELECT VALVE
6
5
AV9-8 AUTOMATED
STREAM SELECT VALVE

Valve Plumbing
Both the V9-8 and AV9-8 valves accept 1/4-28 flat bottom fittings, and either 1/16" OD/0.020" ID Tefzel
tubing or 1/8" OD, 0.062" ID PTFE tubing may be used. To maintain bio-compatibility, all wetted parts are
non-metallic. The V9-8 and AV9-8 Stream Select valves have numerous uses as part of a chromatography
system, and this will determine the plumbing. Three examples are provided in the following pages.
Note: Always manually prime all pre-column valves before initiating a run. Failure to displace air with buffer could stall the
BioLogic Gradient Pumps or lead to erratic flow.
Example 1. Sample Selection.
The AV9-8 may be used for selecting up to 8 samples for consecutive chromatography runs. Typically, one of the
eight positions holds a rinse solution to clean the sample loop and fill lines between sample injections. For this
example, 1/16" OD/0.020" ID Tefzel tubing is recommended.
V7-3 OR AV7-3
LOAD
POSITION
WASTE
1
2
3
4
LOOP OVERFILL
TO WASTE
8
1
2
9
3
4
SAMPLE #3
COLUMN
7
6
5
7
6
5
EP-1 ECONO
PUMP
GRADIENT
PUMP
RINSE
SAMPLE #1
SAMPLE #2
V7-3 OR AV7-3
INJECT
POSITION
1
2
3
4
1
2
3
4
SAMPLE #3
5
8
9
COLUMN
7
6
LOAD
PUMP
PURGE
7
5
GRADIENT
PUMP
LOAD
PUMP
6
STATIC
LOOP
RINSE
SAMPLE #1
SAMPLE #2
V9-8 OR AV9-8
LOADING DIRECTLY ONTO A LOW PRESSURE COLUMN USING A PERISTALTIC PUMP TO FILL A STATIC LOOP
V9-8 OR AV9-8
In the illustration above, the following two configurations are shown:
• Using a peristaltic pump to load directly onto a column: To load samples onto a column with low
backpressure, bypass the sample loop and directly load sample from the Model EP-1 Econo Pump onto
the column.
• Using a peristaltic pump to fill a static loop: The system can be configured so that the Model EP-1
Econo Pump automatically loads the sample loop. Load at least a 3-fold excess of sample into a static
loop with the peristaltic pump. This helps to ensure that the sample loop is completely filled with
sample prior to injection.

Example 2. Buffer Selection
Placed upstream of the BioLogic Gradient Pumps, the V9-8 or AV9-8 allows selection of up to 8 different
solutions. When used in this manner, buffers for different types of chromatography and for column sanitation
may be used as part of an automated separation procedure. For an ion exchange separation, often several buffer
systems with different pH conditions are used to optimize a separation. By using the 8-ports, eight different
buffering systems are set up for evaluation. An example of this configuration is shown below. For this
example, 1/8" OD / 0.062" ID PTFE tubing is recommended.
NOTE: During valve position changes, either stop the Gradient Pump or run the Gradient Pumps at a slow flow rate (<1
ml/min). Failure to do so could lead to generation of air bubbles in the Gradient Pumps.
A1
GRADIENT
PUMP
A
8
1
2
3
A2
4
A3
V9-8 OR AV9-8 V9-8 OR AV9-8
7
9
6
B1
5
B2
B3
A4
INJECT
VALVE
1
2
V7-3
OR
3
AV7-3
4
B
8
1
2
3
4
7
9
5
B4
COLUMN
7
6
5
6

Example 3. Fraction Collection.
Placed downstream of a column, the V9-8 or AV9-8 may be used as an eight-place fraction collector either for
separations which generate large volume fractions or separations where a fraction collector is not appropriate.
For this example, 1/16" OD/0.020" ID Tefzel tubing is recommended.
V7-3 OR AV7-3
GRADIENT
PUMP
LOAD
POSITION
2
3
4
COLUMN
1
7
6
5
FRACTION #1
FRACTION #2
FRACTION #3
8
1
2
3
V9-8 OR AV9-8
9
4
FRACTION #4
7
5
6
FRACTION #8
FRACTION #7
FRACTION #6
FRACTION #5
Valve maintenance and repair
Model V9-8 and AV9-8 valves should be rinsed with water following use with aqueous buffers, or 20% ethanol
following use with non-aqueous solutions. Never allow salt solutions to dry inside the valve. For repair of
Model V9-8 and AV9-8 valves, contact your local Bio-Rad office.
Ordering Information
750-0403 Stream Select Valve, V9-8
750-0408 Automated Stream Select Valve, AV9-8
750-0602 1/16" OD/0.020" ID Tefzel tubing, 30 feet
750-0603 1/8" OD/0.062" ID PTFE tubing, 15 feet
4106040 Rev C