I don't know of any specific REVIT viewers.
Googling, I found Autodesk Design Review (I'll admit I need to go research it a bit to see if it handles Revit files or if you need to export the Revit files out to something that ADR can see.)
Downloads are available here: Autodesk Design Review – DWF Viewer, Measure, Markup, and More

I know it comes with the software as I am looking at my start menu now. when our IT guy installed the software, they installed the viewer however, I cannot locate a download from the autodesk website.

Thanks for your help as you have done so many times before.

Huh!?! Well, lookie there! (Forgive me, since I have RST installed, I don't really need a viewer, now, do I?)
So, I found what you're seeing, "Revit Structure Viewer 2012" in my programs. So I clicked on it.
At first glance, it looks like it pulls up the regular, fully operational RST. Then I get a Revit Current License Status that tells me that RST2012 is in Viewer mode. It goes on to say what is and is not allowed in Viewer mode.

To me, it looks like whoever is going to have this RST Viewer needs to have a full install of RST... it just won't access the fully functional license to run the program; IOW, they won't be able to save, export or print.

I believe you can install RST, without a license, by getting a "trial" version of RST from Autodesk.

Leanne is correct. You can install Revit (any flavor btw) and simply let the demo-license expire. Afterwards it will operate as a viewer... (with added irritating popups about getting a license and no possibility to save, export or print)