| 摘要 |
The valve comprises a body constituted by two pieces (10a) of rigid synthetic material. The two pieces (10a) have an at least substantially specular shape with respect to one another and mate along a median plane containing the axis of an operating shaft (20) on which is fitted a disc-like butterfly shutter (18). The two pieces (10a) have respective annular parts (12a) which define the lumen for passage of fluid in the valve, in which the shutter (18) is located. In the lumen there is fitted an annular metal insert (24) diametrally traversed by the operating shaft (20). The annular insert (24) is lined, preferably by vulcanisation, a seal (26) of elastomer which comprises a layer (46) which clads an inner cylindrical surface of the insert (24) and is sealingly engagable by the periphery of the shutter (18). |
