Tap for compressed or liquefied gases

Tap for compressed or liquefied gases, comprising a body (10) containing a closing member for opening or closing the passage of the gas between an inlet connection piece (12) and an outlet connection piece (14), and also a control valve (20) for controlling the flow of the gas between the inlet connection piece (12) and the outlet connection piece (14) and comprising a piston (28) sliding non-sealingly in a cylindrical receptacle (26) and carrying on one of its faces a closing seal (30) for closing the passage of the gas, and a spring (40) stressing said piston (28) axially in the closing direction of the passage, characterized in that said spring (40) is mounted in an axial cylindrical pocket (38) of the piston (28) and is compressed between the bottom of said pocket (38) and a cylindrical block (42) which is likewise engaged at least partially in said pocket (38), said cylindrical block comprising a seal (44) ensuring leak-tightness relative to the side wall of said pocket (38) during the sliding of the piston (28) relative to said block (42), and in that said block (42) comprises an axial duct (46) provided with means for braking the passage of the gas through this duct (46).