摘要 |
<p>An improved balanced valve includes a radial arrray of pressure sensing passages in the main disc which extend from the axial opening to a peripheral region of the disc below the seating surface of the disc such that when fluid flow reverses, as when there is a rupture of the first flow passage, an upward force is generated on the main disc just prior to closure which tends to resist the closing force on the valve, the pressure sensing passages allowing a higher fluid pressure to be communicated to the region above the main valve disc assembly to effectively oppose this resistance to closure.</p> |