Butterfly valve for circular pipe section - has plastics pipe made slightly smaller than valve plate to give sealing at periphery

摘要

The round pipe (1) made from elastic plastic, encloses a circular plate located by a diametrical hinge pin (3). By rotating the plate by an external lever, the pipe can be blocked to prevent any gas or liq. flow. To obtain an adequate seal between plate and pipe for low pressure differentials, the flexible pipe has a dia. of 1 to 3% less than the valve plate. By providing an interference fit for the hinge pin (3), the valve plate will remain in the position that was selected.