| 摘要 |
<p>A ball valve has a cartridge comprising a sleeve (38) and constant flow regulator device (44) inserted into a bore (34) through the ball (20). A further constant flow regulator (50), of higher flow rating, is located in an outlet port (14) of the valve. When the ball bore is aligned with the flow axis, all flow passes through the ball bore and the lower flow rating regulator (44) is dominant. At 45 DEG to the flow axis, flow by-passes the ball, passing through a surrounding ball chamber (18), and the flow rate is determined by the higher flow rating regulator (50). In the closed condition of the valve the cartridge can be extracted from the ball bore through an aligned access port (16) for maintenance or exchange of the lower rating regulator. <IMAGE></p> |
