Patent attributes
A circulation control valve can include first and second valve devices and at least one opening which provides fluid communication between an interior longitudinal flow passage and an exterior of the valve. Fluid communication can be provided through each of the first and second valve devices in response to application of a respective one of first and second pressure differentials applied across the corresponding valve device via the interior longitudinal flow passage. Fluid communication in any direction through the opening may be permitted in response to application of the first pressure differential to the first valve device. Fluid communication through the opening may be prevented in response to application of the second pressure differential to the second valve device.
