The invention relates to a gas cylinder valve comprising a body (1) through which a passage (112) ending in a sealing seat (113) extends axially, into a chamber (13) upstream of an outflow nozzle (14) housing a valve stopper (3) screwed into the nozzle (14). The stopper consists of a sleeve (31) receiving a valve (32) pressed against the sealing seat (315) of the sleeve. The sleeve (31) has a tool grip (314) downstream of the valve (32) for screwing/unscrewing the stopper (3) into and out of the nozzle (14).
