An improved method and device for securely inserting a tubular element (30) into a through-aperture (40) in a flexible wall (60) accessible from one side only. The tubular element has a retainer (31, 32) projecting transversely at each end thereof, said retainer being resiliently foldable towards the axis of said tubular element. The element is inserted into a loading tube (11), wherein the retainers are automatically folded into the correct orientation by an automatic bending means (18). The bending means is part of a self-contained device for inserting said tubular element (30) into said through-aperture (40).
