an automatic storm choke valve having two vertically spaced - apart valve members movable longitudinally within a valve housing to open and close the valve . a pair of vanes pivotally affixed to an upper valve member at its lower end are kept in a preset oblique position by a pair of compression springs , mounted within the upper valve member , allowing a predetermined amount of fluid to pass through the valve . the vanes cause the valve members to rotate responsive to an upward fluid flow within the housing . a pressure equilization chamber affixed below the lower valve member is provided with a compression spring , which in its expanded position tends to keep the valve open .