Design and Analysis of Flanged Skirt Splices for Tall Pressure Vessel Towers

Abstract

Pressure vessel towers used in the petrochemical and chemical industry are designed to accommodate numbers of internals including trays and beds resulting in tall vertical structures. Transportation of tall towers from the fabrication shop to the construction site presents challenges that can result in high transportation costs or a logistically impossible task of moving the vessel. One of the solutions to this problem is to shorten the tower for transport by cutting part of the tower skirt and welding it in the field. Depending on the location, welding on site can be expensive, labour intensive and may cause problems in the quality of the weld and the tower being out of level. Using a flanged skirt connection will reduce the field labour spent on connecting the bottom part of the skirt to the rest of the vessel. The challenge that lies in front of designers is that the current codes and available literature do not give a specific design and calculation guidance for implementing such a solution. This paper looks at different analytical methods to be used for the design of a skirt splice. Methods provided by Jawad and Farr, the Canadian Institute of Steel Construction, the American Institute of Steel Construction, and the Peterson Method from the European Commission’s High-Strength Tower in Steel for Wind Turbines (HISTWIN) are analyzed. Based on this analysis, the most optimal and safe design and fabrication methodology for implementing a Flanged Skirt Connection is proposed.