A valve element selectively opens and closes a radial aperture and an axial hole in a drilling element for drilling mud circulation. The valve element includes a fixing portion allowing the valve element to sealingly fix to the drilling element at the radial aperture. A body has an inlet aperture and an outlet aperture, and a duct for putting the apertures in communication with each other, defining a path for the drilling mud. A plug selectively seals the inlet aperture. A first sealing element is positioned in a housing formed in the axial hole of the drilling element. A shutter pivoted to the body includes a second sealing element to selectively and sealingly close the outlet aperture. The shutter selectively and sealingly closes the axial hole by abutting against the first sealing element. The valve element is adapted to keep the outlet aperture of the body normally closed.