PLASTIC BUTTERFLY VALVE

摘要

A plastic butterfly valve wherein an annular sheet (3) is fixed to an inner peripheral surface of a flow passage in a hollow cylindrical body (1) by mea ns of a sheet presser member (2), and a peripheral edge of a valve disc (4) supported in the body (1) to enable eccentric revolution is adapted to conta ct with the annular sheet (3). The sheet presser member (2) is detachably fitte d on one (12) of sides of the body (1) by means of insertable rotation means. The insertable rotation means comprises a plurality of arcuate projections ( 9) on an outer peripheral side end surface of the sheet presser member (2), an arcuate notch (5) provided in a position corresponding to the projections (9 ) on the body (1), and an engagement groove (6) for guiding the projections (9 ) at the back side of the notch (5). The use of the insertable rotation means facilitates mounting and dismounting of the sheet (3) to from the body (1), and enables assembling thereof in a short time.