Is PVC conduit considered dust tight?
What type of fittings should I use?
For combustible dusts it would be Article 502. It would also be Class II, not Class 1.dusttight also has to do with boxes and fittings, etc. better look at 501 nec, definition of dusttight and class 1 div1 locations, wiring methods. at a quick glance, not approved unless its encased in 2 inches of concrete.