Hot Tap Fittings - To Extrude or Fabricate
(Room Conference Hall)
04 Apr 18
9:30 AM
-
11:00 AM
A common means of accessing a pipeline for such operations as diversions, new connections, maintenance, etc. is to use a hot tap. Hot taps are widely accepted in the industry and offer several advantages over shutting down the pipeline such as reducing production downtime, eliminating the loss of pipeline product and preventing unwanted carbon emissions. Split tee fittings are the most effective way to complete a hot tap and are designed in such a way that they can be left in place on the pipeline safely while minimizing future integrity risks and impact to operations. There are two ways in which these fittings can be manufactured; one is to use a welding fabrication method whereby a branch connection is welded to a run with associated opening. The second is to use an extrusion technique that forms heated plate or cylindrical shell into a tee shape. Techniques used in extrusion must be tightly controlled to ensure correct wall thickness, material homogeneity, mechanical properties, and geometric conformity. Fabricated fittings must have rigidly controlled rolling, cutting, welding, and heat treatment when applicable. This presentation will offer the advantages and challenges of both techniques, as well as solutions to those obstacles, and how modern analysis methods (Finite Element Analysis) helped in the development of a new extrusion process to overcome the issues associated with this method. The presentation will also highlight what operators need to consider when choosing between an extruded or fabricated fitting along with what codes and standards are pertinent to these fittings.