The present disclosure describes a pressure support therapy device valve that enables a subject to safely supplement therapy pressure support with low flow oxygen while using a heated (or non-heated) tube. The valve conducts a pressurized flow of breathable gas and the low flow oxygen to the heated tube. The valve includes electrical components configured to pass power from the pressure support therapy device to the heated tube, and a plunger biased to close a flow path from the pressure support therapy device when a pressurized flow of breathable gas is not provided (or is below a predetermined pressure threshold). Closing the flow path stops oxygen gas from flowing back through the valve toward the pressurized gas source.
