Abstract: The invention relates to a valve for volatile liquids such as an expansion valve for a refrigeration plant. Magnetic valves of this type have a plunger actuated closure member which controls a small throttle opening which functions to vaporize the cooling liquid. The valve action can be noisy and damping chambers have been provided for damping the movement of the plunger. As disclosed herein such a damping chamber is disposed in the flow path downstream from the throttle opening where a cooling vaporization occurs and the cooling vaporization is effective to minimize vaporization in the damping chamber which would otherwise reduce the effectiveness of the damping chamber.