Device for closing an end of a tube having an axial direction (a), such as a water supply tube, said device comprising: - a closing element arranged for being in contact with an outer surface of said tube, said closing element comprising a clamping portion for clamping, via said closing element, said device onto said tube and a sealing portion for sealing, by said device, said end of said tube, wherein said closing element comprises a bottom part arranged for capping, in use, said tube and a wall part extending away from said bottom part, wherein said wall part encloses an angle of substantially 90 degrees with said bottom part, wherein said clamping portion comprises said wall part; - a clamping element (5, 105) arranged for, in a first condition of said clamping element (5, 105), transferring a clamping force onto said clamping portion of said closing element for realising, via said closing element, said clamping and arranged for, in a second condition of said clamping element (5, 105), allowing said device to be removed from said tube, wherein said clamping element (5, 105) comprises a plurality of clamping organs arranged for said transferring, in said first condition of said clamping element (5, 105), said clamping force; - an actuation element (7, 107) arranged for bringing said clamping element (5, 105) into said first condition or said second condition by actuation of said actuation element (7, 107) about an actuation axis, characterized in that, - said closing element comprises a thickened wall part at a side of said wall part facing away from said bottom part, wherein said sealing portion comprises said thickened wall part; - said clamping element (5, 105), in said first condition of said clamping element (5, 105) is arranged for transferring a sealing force onto said sealing portion of said closing element for realising, by said device, said sealing; and - said plurality of clamping organs are arranged for transferring said sealing force and wherein said plurality of clamping organs comprises a recess for at least partly receiving said thickened wall part. - a closing element arranged for being in contact with an outer surface of said tube, said closing element comprising a clamping portion for clamping, via said closing element, said device onto said tube and a sealing portion for sealing, by said device, said end of said tube, wherein said closing element comprises a bottom part arranged for capping, in use, said tube and a wall part extending away from said bottom part, wherein said wall part encloses an angle of substantially 90 degrees with said bottom part, wherein said clamping portion comprises said wall part; - a clamping element (5, 105) arranged for, in a first condition of said clamping element (5, 105), transferring a clamping force onto said clamping portion of said closing element for realising, via said closing element, said clamping and arranged for, in a second condition of said clamping element (5, 105), allowing said device to be removed from said tube, wherein said clamping element (5, 105) comprises a plurality of clamping organs arranged for said transferring, in said first condition of said clamping element (5, 105), said clamping force; - an actuation element (7, 107) arranged for bringing said clamping element (5, 105) into said first condition or said second condition by actuation of said actuation element (7, 107) about an actuation axis, - said closing element comprises a thickened wall part at a side of said wall part facing away from said bottom part, wherein said sealing portion comprises said thickened wall part; - said clamping element (5, 105), in said first condition of said clamping element (5, 105) is arranged for transferring a sealing force onto said sealing portion of said closing element for realising, by said device, said sealing; and - said plurality of clamping organs are arranged for transferring said sealing force and wherein said plurality of clamping organs comprises a recess for at least partly receiving said thickened wall part.