Ductwork, for arranging at least one pipe through an opening in a partitioning, has a flange with a central area having a guide opening for every pipe, the flange having plural mounting apertures, an inner side of the flange being adapted for bearing against a side of the partitioning. The ductwork also has a connecting arrangement mounted in each mounting aperture and has a force transmitter with an operating member disposed over an outer side of the flange. A shank extends through the mounting aperture, over which a clamping device is displaceable around and/or along the shank by actuating the operating member. An engagement arrangement disposed between the inner side of the flange and the clamping device has contact surfaces interacting with contact surfaces on the clamping device, and engaging faces that are displaceable radially relative to the shank by the operating member.