| 摘要 |
PCT No. PCT/SE97/01023 Sec. 371 Date Mar. 8, 1999 Sec. 102(e) Date Mar. 8, 1999 PCT Filed Jun. 11, 1997 PCT Pub. No. WO98/10207 PCT Pub. Date Mar. 12, 1998A positively controlled ball valve for flowing fluids, in particular water, for instance for use in snow making machines. The valve includes a valve housing (1) having a flow passageway (3) for the water (7), a valve seat (9) arranged in the flow passageway (3), and a valve ball (10) which is movable towards and from the valve seat (9). A force actuation device (4) having a piston rod (20) positively acts on the valve ball (10), which is movable in a race (11) in the valve housing (1). The race extends from the valve seat (9) obliquely outwards-rearwards, upstream of the flow of water (7). The force actuation device (4) is formed with a piston rod (20) arranged for being able to force the valve ball (10) in the direction away from the valve seat (4) and into the race (11) for the ball. The piston rod (20) is arranged to act on the valve ball (10), in the first stage of the opening of the valve, so that the ball at least partly rolls out of the valve seat (9). The valve seat (9) is formed with a valve sealing (14) of an elastomeric material having a metal ring (16) engaging the inner surface and the rear end of the valve sealing (14). |
