Question about moving vent stack
I am putting in a small, new bathroom in an area that was previously rough-plumbed as far as the vents and drains are concerned. This area is slab on grade, and I have 2" ABS coming up through the slab for a sink drain/vent and another for a shower drain/vent, as well. There is also a 4" drain for the toilet, and there is a 4" vent stack. All of these are connected under the slab and all of these drains are where I would like them to be, except for the 4" vent stack, which is coming up exactly where a vanity has to go. I can conceal this 4" vent pipe inside the vanity base where it comes through the floor, but I need it to jog over about 18 inches so that it can come up inside a wall.
My question: Is there any reason I can't do a right angle at the floor, bring the pipe 18 inches horizontally over to the wall underneath the sink, do a second right angle and bring it up inside the wall to the roof? The other vents would, of course be connected to the vertical run of this vent pipe as it goes up through the wall. (I know about the limits for horizontal runs of drains, but I couldn't quite figure out whether there is any similar code requirement regarding a horizontal jog in the vent stack when the jog is below the flood level of the sink.)