Patent ID: 8763507

Claim:
An isolation sub for use with a perforating system comprising: a body having a passage formed axially therethrough and a lateral port connecting the passage and outer surface of the body; an inlet end of the body adapted for connection to a pressure source and in fluid communication with an inlet to the passage; an exit end of the body adapted for connection to a firing head and in fluid communication with an exit of the passage; and a pressure regulator in the passage comprising a valve body axially moveable in the passage having an upper end in selective sealing engagement with a downward facing seat in the passage and a lower end in selective sealing engagement with an upward facing seat in the passage, so that when fluid flows into the passage an amount of which exits the passage through the port in which pressure is dissipated to create a pressure differential between the passage and outer surface of the body, the lower end of the valve body moves into sealing engagement with the upward facing seat and defines a flow barrier in the passage between the inlet and exit ends of the body.