The short answer
Spools fabricated off site to drawings go in faster and keep hot work off a busy plant; site running suits lines whose route can only be fixed once the plant around them exists. Most jobs use both. At Discovery Park KBVI prefabricated to drawings and site ran the rest over two years.
Off site fabrication
When the drawings are firm and the plant they connect to already exists on paper, spools are fabricated to those drawings before the crew is on site. The benefit is time on site and control: the welding is done in the shop, the spools arrive ready to drop in, and a shutdown window is spent installing rather than making.
Site running
Some lines cannot be drawn until the plant around them is real. Tie-ins to existing pipework, routes through congested plant, and the last few metres of any run are measured and made on site. On a refit on a running steelworks, that is most of the job.
Most jobs use both
At Discovery Park in Kent, a new build 27.8MW biomass plant, KBVI prefabricated to drawings and site ran the rest, and stayed two years to work nearly every pipeline in the plant. On the BOS plant July 2026 outage at British Steel, prefabrication before the shutdown meant the window was spent on installation.
- 01Firm drawings and open ground: fabricate off site
- 02Tie-ins and congested routes: site run
- 03Outage windows: prefabricate everything possible beforehand
- 04Small bore to large diameter, carbon and stainless, either way
Do you have your own fabrication?
Yes. KBVI is based in Scunthorpe with its fabrication there, and fabricates on site where the job calls for it.
What materials?
Carbon steel and stainless steel, small bore up to large diameter.
