Check out the different styles of hangers. Figure #94 flipped upside down with the set screw on top should be fine(need to measure the height of the lip), one on each side with a piece of 1-5'8" Unistrut cut to length and bolted to each clamp. I would get the 1/2" threaded size to be on the safe side. I hang very large pipe from clamps like this. Your beam will fail before the clamps do. Anvil Company
Hope this helps.