EMT with compression fittings is suitable for Class II,Division 2.
Sealing is dependent on the enclosure type, whether Division1 or 2:
· Dust-ignitionproof enclosures shall be “sealed” per 502.15. Enclosures must be dusttight or dust-ignitionproof, as necessary, without a gasket.
· Dusttight enclosures are not required to besealed.
Robert B. Alexander, P.E.
"I know that you believe you understand what you think the NEC says, but I am not sure you realize that what you read is not what it means." (Corollary to Charlie's Rule)