| 摘要 |
<p>1395038 Valves ITT INDUSTRIES Inc 11 Oct 1972 [18 Oct 1971] 46783/72 Heading F2V A rotary ball valve has a plug 7 with an indentation 33 formed by a plurality of overlapping conical cavities 34, 35, 36 and 37 of different diameters, whereby the presentation of different portions of the indentation to the periphery of the inlet 2 varies the flow through the valve. With the valve in the "closed" position there is a clearance of approximately À032 inches between the seat 23 and the face of the plug. As the plug is rotated towards the open position flow is first controlled by the indentation 33 and a part circular aperture 56 and later by the aperture alone to provide a linear relationship between the angular rotation of the valve and the percentage increase in flow rate from approximately 7 to 8% of valve travel to 100% of valve travel. In the example described, cavity 34 is drilled to a depth of ¢ inch by a 1 inch drill, cavity 35 to a depth of <SP>9</SP>/ 16 inch by a 1# inch drill, cavity 36 to a depth of <SP>25</SP>/ 32 nd by a 1<SP>9</SP>/ 16 inch drill and cavity 37 to a depth of <SP>13</SP>/ 32 nds inch by a <SP>13</SP>/ 16 inch drill, the apexes and the tangents of the base circles of the cavities being joined together by filing or milling. The valve may be rotated by a motor 20 and has a trap 11 with a drain hole 14 into which sediment flows through holes 12, 13 in a circular guide plate 21.</p> |
