A gas purge valve comprising a housing formed with a fluid inlet and a fluid outlet, said fluid outlet bounded by a kinetic valve seating, and a sealing assembly comprising a float member coaxially displaceable within the housing, and a sealing cap coupled to said float member; the sealing cap being axially displaceable with respect to the float member between a first position in which it conjoins the float, and a second position in which it departs from the float; said sealing cap formed at an outside face thereof with a kinetic seal fitted for sealing engagement of the kinetic valve seating, and an automatic valve aperture formed in the sealing cap and bounded by an automatic valve seating; and an automatic sealing member articulated at an upper end of the float member for sealing engagement of the automatic valve seating.