In which scenario are metal conduits permitted when used with listed threadless fittings?

The scenario where metal conduits are permitted when used with listed threadless fittings is in Class I, Division 2 locations. In these environments, the presence of flammable gases or vapors is not expected under normal operating conditions but may occur under abnormal situations. The use of metal conduits in this context is allowed because they help contain any potential hazards by preventing the escape of ignitable materials and ensuring safe electrical installation.

Metal conduits also provide a robust solution for electrical wiring that can resist physical impact and environmental challenges, characteristics that are particularly important in industrial sectors. In Class I, Division 2 locations, using threadless fittings helps eliminate the risk of sparks and maintains the integrity of the conduit, enhancing safety measures.

Other classifications, such as Class II and Class III locations, have different requirements that may restrict or specify alternative methods for electrical installations, focusing more on the presence of dust and other hazards rather than flammable gases.