Filler coupling and corresponding receptacle and filling method

A filler and withdrawal coupling for a pressurized gas receptacle designed to interact with a packaging connector in order to allow said receptacle to be filled and for gas to be withdrawn, the coupling comprising a body defining an internal withdrawal circuit between an upstream end adapted to be capable of connecting to a packaging connector and a downstream end adapted to be capable of connecting to a receptacle, the coupling comprising an isolation valve that is capable of moving relative to a seat between an upstream position capable of closing the internal withdrawal circuit and a downstream position capable of opening the internal withdrawal circuit, said isolation valve adapted to be moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being capable of moving relative to the body between an upstream position capable of closing the upstream end of the internal withdrawal circuit and a downstream position capable of closing opening the internal withdrawal circuit upstream end, said dust-prevention valve capable of closure by being moved to its upstream position by a return member, wherein the dust-prevention valve comprises a filter interposed on the path of at least a portion of the internal withdrawal circuit, the filter being adapted to move with the dust-prevention valve.