US Patent 9458698 Linearly indexing well bore simulation valve

Stimulation valves are provided that have a valve housing, an indexed driver, a reciprocating shifter, an actuation seat, and an isolation seat. The indexed driver is linearly actuated from an initial position through intermediate positions to a terminal position. In the driver initial and intermediate positions, the valve body shuts off fluid communication through ports provided in the housing. In the driver terminal position the valve body allows fluid communication through the ports. The reciprocating shifter indexes the indexed driver from its initial position through its intermediate positions to its terminal position. The actuation seat receives a ball for actuation of the shifter and releases the ball after actuation of the shifter. The isolation seat allows passage of the ball when the indexed driver is in its initial and intermediate positions and receives the ball when the indexed driver is in its terminal position.