Design of Pipe Racks Using Pre-assembled Units or Modules

Pre-assembled units (PAUs) or modules have been widely used for industrial pipe racks. Compared with traditional stick-built construction, using PAUs or modules can accelerate the construction schedule for maximization of shop fabrication, resulting in lower field installation cost. It can be suitable for a plant revamp project due to space limitations and turnaround period requirements, or a project located in a remote or an environmentally sensitive area. However, modular construction requires considerable construction planning and involves logistical challenges. Structural members and connections need to be detailed and suitable for construction sequencing and various types of conditions: shipping, setting, lifting, modular assembly, and fitting for final installation. This paper addresses such challenges, primarily focusing on the considerations of structural analysis and construction detailing.