CEC- part I question

I am working on a project and not sure about some of the CEC-part I rules, I have the following two questions:

1) Could I run a primary and secondary feeders to/from transformer cables (15kv, 3c, #2, teck primary and 1kv, 3c, 350mcm secondary in the same conduit?), as the code calls for a barrier. I know I can not run two different voltages in one conduit if the lower voltage circuit cable has to be rated to the same voltage insulation as the higher one. But I do not know if both are teck cables whether I can run two different voltages in the same conduit?

2) On the cable tray there is existing 15kv URD cable, and I want to run a new 3c-teck 1kv cable, does the teck armored be considered as a mechanical separation running with URD. I know if both circuit are armored, yes the armor is enough physical separation, but if one circuit is URD and one is teck, is still enough mechanical separation?