AES was contracted to study the design requirements to join steel to PE100 to deliver an innovative durable PE100 Stub End flange.

AES designed and delivered custom stub end flange solution that is machined from a 1900mm outer diameter and 250mm thick walled HDPE 100 pipe element, which properties meets the same specification requirements as the long extruded HDPE 100 pipe elements. The stub end is joined to the pipe element via butt fusion weld and is used as the transition piece to transfer the axial tension and moment loads to the steel Y-piece through the clamped thrust collar.

The design has been subjected to an exhaustive FEA analysis and numerous profile iterations to optimize the stress distribution across the joint and minimize subsequent strain and creep over the lifetime.

One of the challenges was to hold the fabrication tolerances of 0.0 mm and +0.5 mm that is presented by the large dimensions of the PE pipeline fitting. The extremely high dimensional accuracy demanded due to the transition of from PE to steel in the joint design.

Designed and delivered custom stub end flange solution that is machined from a 1900mm outer diameter and 250mm thick walled HDPE 100 pipe to survive simultaneous bending, torsion, tension and internal pressure loads.


AES awarded Reiner Ritz to fabricate the Prototype units. Following the number of prototype fabrications AES successfully put the units into dry-fit assembly testing and completed extensive external load testing on the joints to verify the dimensional accuracy and design solution under  tensile loads, moment loads, torsion loads and hydrostatic loads in various magnitudes and axes simultaneously.

Complex design solution is achieved to meet the demanding fabrication tolerances that was presented by the large dimensions of the PE pipeline fitting.