| 摘要 |
<p>1,083,768. Valves. DRESSER INDUSTRIES Inc. Feb. 24, 1966 [Feb. 24, 1965], No- 8303/66. Heading F2V. A pressure-relief valve includes a disc 18 cooperating with a seat 38 and a member 34 movable with the disc and co-operating with a surface 44 to provide a secondary orifice y which decreases in area as the disc lifts. The seat 38 is formed on a member adjustably mounted on an inlet nozzle 16. As the steam discharges, it impinges on a horizontal surface 32 to provide rapid opening, the area of the secondary orifice decreasing most rapidly during initial movement of the valve to maintain the reaction effect of the escaping steam at its optimum value throughout the full movement of the valve. Closing of the valve is also accelerated by the effect of the secondary orifice.</p> |
