| 摘要 |
<p>A flow pressure sensing control valve system is disclosed for use with blowout preventers having an operator cylinder and piston for closing of the blowout preventer, wherein the operator cylinder and piston have a closing side and an opening side and wherein the closing side has a greater effective surface area than the opening side. The system includes a sensing means for dropping pressure of flow directed to the closing side relatively with increases in the flow velocity of the fluid flow. A fluid return system is included for selectively directing the fluid from the opening side of the operator piston to the closing side of the operator piston when the drop in pressure across the sensing means attains a magnitude above a predetermined value in order to reduce fluid capacity requirements and alternatively to direct flow from the closing side to a discharge point when the drop in pressure decreases below the predetermined value. A sequence valve for selectively initiating the flow to the sensing means for use in combination with the sensing means and fluid return system is also disclosed.</p> |
