There is provided a regulation valve for a life support system for use in an aircraft cabin. The valve may have a gas inlet, an air mask supply outlet connected to the gas inlet, and a pressure vest branch interconnected between the gas inlet and an opening. The valve may further have a decompression valve adapted to inhibit gas flow from the pressure vest branch to the air mask supply outlet if pressure in the aircraft cabin decreases below a predetermined value, a one-way valve adapted to inhibit gas flow from the pressure vest branch to the air mask supply outlet at a predetermined pressure difference between the pressure vest branch and the gas inlet, and a one-way dump valve adapted to direct gas from the pressure vest branch to the environment at the predetermined pressure difference between the pressure vest branch and the gas inlet.
