A downhole fluid control apparatus comprises first and second conduits for providing communication between a pressure source and a downhole device, and a valve provided within a housing and configurable between a first configuration in which the first and second conduits are in pressure communication via the valve, and a second configuration in which the first and second conduits are isolated from each other. The apparatus further comprises an actuator for operating the valve. The actuator is in pressure communication with the first and second conduits and with an ambient region external of the apparatus such that when the pressure within each of the first and second conduits is lower than the ambient pressure the valve is configured in its first configuration, and when the pressure within at least one of the first and second conduits exceeds the ambient pressure the valve is configured in its second configuration.