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Prefabrication of pipe spools
Jan 13, 2017

Pipe spools are fabricated from a number of raw pipes and pipe fittings (e.g. elbows, flanges, tees, etc.) in fabrication shops. Raw pipes are cut to the required sizes and moved with pipe fittings to a fitting table, where some of the components are fitted together (i.e. temporarily connected). The resulting sub-assembly (part of the final pipe spool) continues with welding operations (i.e. permanent connected) before it comes back to the fitting table and gets fitted with other spool components.


Spool fitting and welding can be grouped into two types:

  1. Roll fitting and welding

  2. Position fitting and welding


Roll fitting and welding means the main pipe can be turned by a rolling machine and the fitter or the welder does not have to change his position to perform the operation, whereas position fitting and welding occur when one or more branches of the main pipe exceed the clearance limit. In such case, the fitter or the welder has to move around the main pipe run to accomplish fitting or welding. As a result, position fitting and welding usually takes more time to finish than roll fitting and welding. To minimize number of position fitting and welding is one of the goals of pipe spool fabrication sequencing.