| 摘要 |
<p>1534603 Valves MAEZAWA INDUSTRIAL Inc 6 Aug 1976 [2 Sept 1975 (2)] 32814/76 Heading F2V In order to reduce cavitation in a sleeve valve having a sleeve 9 movable over a fixed perforated sleeve 10, an inner perforated sleeve 13 is fixed within the fixed sleeve at the initial opening end thereof and has partitions 15 extending between the two fixed sleeves. Over 70% of the length of the sleeve 10 there are perforations 11 spirally arranged and spaced apart twice their diameter and over the remaining 30% there are large aperture(s) 12 which may be replaced by a space between the ends of the sleeves 9, 10 in valve full-open position. The flow through aperture(s) 12 is equal to that through perforations 11. The sleeve 13 is shown frusto-conical but may be formed as a stepped-cylinder and is perforated so that the flow area into the spaces between the sleeves 11, 13 and the partitions is equal to that out of the spaces. The sleeve 9 is moved by a piston-cylinder 21, bevel gearing (47, 56), or a push rod (67).</p> |
