Patent ID: 8757265

Claim:
A frac valve for a well liner, said frac valve being adapted for use in fracturing a well formation and comprising: (a) a cylindrical housing adapted for assembly into said liner for a well and defining a conduit for passage of fluids through said housing; (b) said housing having an inner wall and an outer wall, said inner wall and said outer wall being spaced from each other to define an annular space therebetween and each having a plurality of ports therein allowing passage of fluids between said conduit and the exterior of said housing; (c) a valve body mounted in said annular space between said inner wall and said outer wall, said valve body comprising a cylindrical sleeve which is repeatably moveable between a closed position in which fluid communication between said ports is shut off and an open position in which fluid may flow between said conduit and the exterior of said housing through said ports; and (d) an actuator adapted to move said sleeve between said closed position and said open position; (e) wherein said actuator comprises a receiver adapted to receive an activation signal from a transmitter introduced into said conduit; and (f) wherein said housing comprises a first set of vent ports in said inner wall and disposed in said annular space above said sleeve and a second set of vent ports in said inner wall and disposed in said annular space below said sleeve, said sets of vent ports adapted to cooperate with each other to allow fluid to be displaced from and flow into said annular space upon movement of said sleeve between said closed position and said open position.