The invention relates to a Device (10) for separating a tubular web (11) in two flat webs (12, 13) with an adjustable blade (20) for cutting the tubular web (11) and with a pulling device (30) which impinges the blade (20) with a tensile force (K) on a folding edge (14) of the tubular web (11) wherein the pulling device (30) is configured in a way that the tensile force (K) is adjustable depending on the tubular properties of the tubular web (11) and that the tensile force (K) can be mainly kept constant with constant tubular properties independent from the tubular web (11).

Systems, methods, and devices for perforating louver perforations into a pipe are contemplated. Systems, methods, and devices for transporting pipes for perforation are contemplated. Systems, methods, and devices for performing quality control inspections of such perforations contemplated. A pipe may be oriented vertically and raised over a device that punches perforations into the pipe from the inside of the pipe toward the outside of the pipe. Various supports may contact the pipe for stabilization and to facilitate the formation of perforations without removing cut away pieces from the pipe. Electronic monitoring of the features of the pipe facilitate quality control inspection during processing. In this manner, a structurally robust pipe having a series of louver perforations along the pipe may be formed.