What are pipe spools?
Industrial construction includes a wide range of projects, such as petroleum refineries and chemical and power plants. This type of construction involves intensive piping, which connects a variety of equipments and conveys process fluid and gas. Due to compressed schedule and limited space on site, industrial construction projects rely heavily on the offsite fabrication and assembly. Pipe spools allow pipe assembly in the early stages of a construction project. Also, pipes are easier to connect inside a climate-controlled facility than at the construction site, and pipe assemblies can be moved around and manipulated while they are being welded together off-site. If they are assembled at the work site, manipulation is usually impossible, and welders need to move into awkward positions to complete their work. As such, piping work is divided into two stages: Pre-Fabrication of Pipe Spools and site installation.
Pipe spools are fabricated using various types of raw pipes and pipe fittings and they include flanges, elbows, tees, and a lot more. They are usually fabricated offsite. The raw pipes are pre-cut to specific sizes and together with pipe fittings and other components. They are temporarily fitted together. This partially finished sub-assembly is then welded with other spool components.
The entire pipe spooling process can be grouped into two:
1. Spool roll fitting and welding
2. Spool permanent position fitting and welding
In spool roll fitting and welding, the main pipe can be turned using a rolling machine and the fitter does not need to alter his position to perform the task. In spool position fitting and welding, a portion or portions of the main pipe go beyond the clearance limit forcing the fitter to move around the main pipe in order to complete the fitting and welding process. That is why spool position fitting and welding is generally a longer process compared to spool roll fitting and welding. Reducing the number of spool position fitting and welding is one of the objectives of pipe spool fabrication sequencing.