Prefabrication

Prefabrication means building parts of an installation in advance, in the contractor’s workshop, rather than on site at the client’s plant.

The most commonly prefabricated items are:

• pipe spools, which are cut, welded and inspected in the workshop,
• steel structures, such as frames, platforms and supports,
• complete modules, meaning sets of equipment assembled on a common frame together with piping and wiring (also called skids).

Working conditions in a workshop are better than in a production hall: the right tools, cleanliness and no clashes with other crews. It is easier to maintain high quality, especially for welds in hygienic piping. Workshop work can also run in parallel with other project stages. Most importantly, the time spent working on site is shorter, and what remains on site is mainly assembling finished components.

Example: In an operating meat processing plant, 200 metres of hygienic piping need to be installed for a new line. If the pipes were welded on site, fitters would spend several weeks working between running machines, in damp conditions, with limited access and a risk of contaminating production. Instead, the pipes are prepared in the workshop: longer sections are welded, the welds are inspected, and the pipes are cleaned and labelled. Finished components arrive on site and are joined together during a short shutdown.