The invention relates to a closing device for a filler neck situated on a container, in particular for a container situated on a rail or road vehicle, which may be supplied to a loading station for loading with powdered or granular bulk goods. At least one filler neck (3), which is provided with a through opening and connected to the container interior (6), and a pivot device (30), which comprises two pivot arms (31, 61) mounted thereon, are situated on the container (5), using which two closure elements (35, 60) situated thereon are pivotable in relation thereto around a shared axis (Z) for the exterior and interior closing or opening of the through opening. At least one seal, which is provided with a pressure chamber oriented around the circumference, for example, and which may be impinged with pressure in the closed position and relieved of pressure to pivot the closure elements, is situated on the closure elements (35, 60) and/or on the filler neck (3).