Wells – Valves – closures or changeable restrictors – Longitudinally movable operator
Reexamination Certificate
2002-09-05
2004-08-10
Tsay, Frank (Department: 3672)
Wells
Valves, closures or changeable restrictors
Longitudinally movable operator
C166S373000, C251S359000
Reexamination Certificate
active
06772842
ABSTRACT:
BACKGROUND
1. Field of the Invention
This invention pertains to flapper valves, and particularly to flapper valves used for well completions.
2. Related Art
Flapper valves are often used in subsurface safety valves. Subsurface safety valves are used in wells to contain wellbore fluids, particularly in the event of emergency situations in which there is potential danger to personnel, equipment, or the environment.
SUMMARY OF THE INVENTION
The present invention improves flapper valves by providing a curved flapper and a seat, the flapper and seat each having complementary undulating and tapered perimeters, with sealing surfaces designed to maintain seal integrity under higher pressure, for a given outer diameter to inner diameter ratio, compared to prior art flapper valves.
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Campos Juan A.
Hernandez Alfred
Read Dennis M.
Echols Brigitte Jeffery
Griffin Jeffrey E.
Tsay Frank
White Bryan W.
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