True, but take the example of pipe spooling. For those of you who have never built a process plant or oil refinery, the piping in the plant is almost always fa

True, but take the example of pipe spooling. For those of you who have never built a process plant or oil refinery, the piping in the plant is almost always fabricated off-site by specialist piping fabricators, who assemble "spools" from individual piping components like flanges, pipe and elbows. The size of these spools are usually limited by the transport envelope - i.e. how big a spool can be transported (say in a 40ft container). Every spool is different, so it is quite labor-intensive to prepare the individual components, weld them together, check all the welds (via x-ray, or ultrasonic testing), and them ship the spool to site. Being able to "print" a spool from a big bath of steel powder could potentially reduce costs significantly. (Consider also, the benefits of being able to use custom-made parts in the piping spools: while a pipe carrying water might only require a standard thickness of elbow, a pipe carrying an erosive slurry would require a much thicker section of metal on the outside of the bends, where the slurry tends to wear away the pipe. The way this is currently dealt with is by making the _entire_ pipeline (not just the elbow) out of thicker materials). This will be a long-time coming, as the current standards for process plant pipe (based on piping made of sections and fittings welded together) are extremely well proven, and exceptionally safe. But in 20 or 30 years......