Emerson Climate has launched high-pressure expansion valves CX4, CX5, CX6 and CX7 from ALCO Controls, suitable for CO2 systems. ALCO Controls CX4/CX5/CX6/CX7 are stepper motor driven valves for precise control of refrigerant mass flow in air conditioning and refrigeration systems with CO2. The control valves can be used as high pressure gas valve for gas cooler control, expansion device, hot gas and cold gas bypass, liquid injection duty, evaporator pressure regulator, crankcase pressure regulator, head pressure regulator, or liquid level control.