A valve assembly for controlling the release or delivery of a fire suppression medium from a vessel, the assembly comprising an inlet connectable to a pressurised vessel, an outlet connectable to a delivery device, a valve operable to selectively open or close fluid communication between the inlet and the outlet, an opening device for moving the valve from a closed condition to an open condition, first and second actuators and an environmental triggering device, wherein the opening device is operable, in use, remotely by the first actuator or manually by the second actuator or automatically by the environmental triggering device. A fire suppression system employing the above-described valve and a vehicle including the fire suppression system also form a part of this invention.