|
The 340 series dispensing valves were the worlds first to combine adjustable positive displacement volume control, automatic, adjustable, suck-back, a completely disposable wetted system and a programmable micro controller operated electronic sequencing system. This allows it to be optimized for even the most difficult to handle materials. The 340 series is particularly useful for dispensing very difficult, high viscosity and/or stringy materials that have short pot lives in applications where the repeatability of positive displacement is required and the simplicity of a disposable wetted system is desirable. The valve is equally at home with thin, low viscosity materials. A number of versions of the valve exist. The basic variations are designed to cover a wide range of dispense volumes, ranging from approximately .001 cc to .5 cc. Versions also exist that allow ganged mounting. Gang mounted valves lower the per valve cost because a group of valves can be controlled by a single control system.
Click here for a pop-up window diagram. The way the dispense valve works can best be understood by visualizing a piece of flexible tubing that is held against a fixed wall and is opened or closed at 4 positions along its length by air operated pistons (see Fig. 1). Two of the pistons (V 1 and V 3) that open and close the tubing are beveled and are used to turn the flow through the tube on and off. The other two pistons (V 2 and V 4) are blunt and are used to displace materials as they move in and out.
The 340 valve works in conjunction with the 340.0.0 controller.
|
