The design of tall pressure vessel towers may be affected by transportation limitations on the overall length of the vessel-plus-skirt. Additionally, process considerations set minimum elevations for the pressure vessel, and plant conditions may dictate whether the vessel needs to be set on a foundation or in a structure. Occasionally, these limitations collide, resulting in a requirement for a longer skirt than can be transported. To enable transportation, the vessel skirt may need to be spliced.
There are multiple methods for which the skirt can be spliced: welded or re-welded at site, sleeve-and-bolt, double-sleeve-and-bolt, and flanged. This paper presents these various methods, and presents an overview of the different design methodologies and considerations for the flanged approach. Design considerations and evaluations necessary for the design and consideration of fabrication tolerances are presented. A case study is introduced for context.