I need a PC to work in a steel fabrication shop.
Theres always a crap ton of stuff in the air so a regular PC case / psu would get clogged up quickly.
I need a closed case design with little to no external airflow as well as a PSU with no fan.
Ya that would work, you could also filter the air - put filter pads on the intake of every fan. This won't allow them to cool the system as efficient since there will be less air flow, but at least there will be air flow.
I do like skeeg idea though - but it may not be economical (meaning a lot of companies aren't willing to fork over the cash for a water cooled system).
Lol I should of seen this thread earlier I know all about rugged pcs as I was planning a build a while back that needed to be waterproofed and extreme heat. Yours sounds a little simpler so I would use a car pc case if budget is an issue: KustomPCs.co.uk - VoomPC-2 CarPC Case
If your looking for slightly bigger there was an mcubed case think it was called a borg that has basically a huge heatsink about micro-atx sized
Even for those cases, dust would get into into the usb slots and drives. You need something like a filtered fan that pushes air through the filter, into the computer, and out of the holes.
PC for a dirty enviroment 
Linear Mode
