For conduit installations in explosion-proof zones, surface mounting is commonly used, although the regulations don’t explicitly forbid concealed installations.
It’s my perspective that both methods are viable. Nonetheless, given the advantages of accessibility for inspections and wire replacements, surface mounting with conduits emerges as a more practical choice. High electrical wiring standards in explosion-proof workshops necessitate careful consideration to prevent damage from external contacts in surface-mounted installations, a concern absent in concealed installations. Additionally, conduits should house continuous wiring, eschewing joints, with any connections accommodated in explosion-proof junction boxes.