Control valve system for blowout preventers
AssigneeNL Industries, Inc.
InventorH. John Bates
Life of this patent
Estimating the term…
Abstract
A control valve system and method are disclosed for blowout preventers having an actuating piston for actuating the closing of the blowout preventer whereby the piston has an opening side and a closing side. The control valve system and method include a means for selectively directing fluid from the opening side of the actuating piston to the closing side of the actuating piston in order to reduce the fluid requirements for closing the blowout preventer and reduce installed horsepower requirements thereby.
Claims8
For use with a blowout preventer having an actuating cylinder and piston for actuating the closing of the blowout preventer, the actuating piston having a closing side and an opening side of smaller effective area than the closing side, a differential pressure control valve system comprising:
- a directional flow control system for directing flow from the opening side of the actuating piston alternatively to the closing side of the actuating piston and to a discharge line;
- and
- a pressure sensitive switching system in communication with the directional flow control system, said switching system being operative, upon the communication of a pressurized fluid to the closing side of said actuating piston, to cause said directional flow control system to direct flow from the opening side of the actuating piston to the closing side of the actuating piston when the pressure at the closing side of the actuating piston is below a predetermined magnitude, and to automatically vary the alternative flow paths of the directional flow control system when the pressure at the closing side of the actuating piston reaches said predetermined magnitude to cause said directional flow control system to direct flow from the opening side of the actuating piston to said discharge line;
- said pressure sensitive switching system further comprising an override system for selectively causing said directional flow control system to direct flow from the opening side of the actuating piston to the discharge line independently of the pressure at the closing side of the actuating piston;
- and
- said pressure sensitive switching system further comprising electrical circuit means for selectively causing said directional flow control system to automatically direct flow in response to the pressure of said pressurized fluid.
For use with a blowout preventer having an actuating cylinder and piston for actuating the closing of the blowout preventer, the actuating piston having a closing side and an opening side of smaller effective area than the closing side, a differential pressure control valve system comprising:
- a directional flow valve, said directional flow valve being in communication with the opening side of the actuating piston, the closing side of the actuating piston, and a discharge line;
- a pressure sensitive switching system in communication with the directional flow valve, said switching system being operative, upon the communication of a pressurized fluid to the closing side of said actuating piston, to cause said directional flow valve to direct flow from the opening side of the actuating piston to the closing side of the actuating piston when the pressure at the closing side of the actuating piston is below a predetermined magnitude, and to automatically vary the alternative flow paths of the directional flow valve when the pressure at the closing side of the actuating piston reaches said predetermined magnitude to cause said directional flow valve to direct flow from the opening side of the actuating piston to said discharge line, said pressure sensitive switching sytem comprising
- a selector valve, said selector valve being in communication with a source of pressurized fluid and with a fluid reservoir on a first side of said selector valve and being in communication with a closing pressure line and with a retracting pressure line on a second side of said selector valve;
- and
- at least one closing pressure sensor in communication with the closing side of the actuating piston and the directional flow valve for selectively varying the path of flow through the directional flow valve;
- and
- said pressure sensitive switching system further comprising electrical circuit means for selectively causing said directional flow valve to automatically direct flow in response to the pressure of said pressurized fluid.
Dependencies are inferred from the claim text.