| 摘要 |
<p>The invention concerns a ball or plug valve for dividing differential pressure into several stages during opening or closing operation of the valve. The valve (1) comprises a body (2) defining a housing (2') for a movable member (3) consisting of a ball (4) or plug (5), and provided with a substantially cylindrical channel (6). The said valve (1) comprises a substantially cylindrical tubular insert (10) received in the said channel (6) and defining at least one inlet chamber (11) and at least one outlet chamber (12). These chambers are diametrically opposite and consist of two longitudinal recesses (13) formed in the wall of the insert (10) parallel to the longitudinal axis (14) of the channel (6). The chambers (11) and (12) communicate via two or more resistords (15) in two cylindrical sectors defined by the said chambers at the periphery of the insert.</p> |
