ABSTRACT
Basic valve design should be considered when selecting pneumatic directional control valves. Since they control direction, they must 42be adequately sealed for the application. The sealing function may be accomplished by shear action or seating action elements. The discussion following describes the typical characteristics of each of the valve types. We do not imply—nor should the reader infer—that any of the valve types discussed may or may not include the characteristics attributed as being typical to any particular design. Specific characteristics depend upon the valve manufacturer's designs. Special applications should be discussed with the valve manufacturer.
