Ductile cast iron pipe having constricted end casing

摘要

The invention provides a pipe or similar tubular member of ductile cast iron having an end casing. The thin walled casing has a curved profile at its entrance divided into two sections, of which one is formed by centrifugal casting, whereas the other, of lesser curvature, is made by hot or cold forming with a simultaneous axial compression and a radial bending directed towards the axis of the pipe. The invention is useful for forming fluid tight seals in pipelines using radial compression packings.