Thank you for the input.
I should have been clearer on the type of clamp I was referring to...it is one that actually rides in the strut. The answers confirm what we have maintained, that typical unistrut and pipe clamps are not listed for fire sprinkler piping use.
WE are seeing more and more cases of unistrut type systems fastening sprinkler piping to building structure. If oriented so that piping is not hanging down against the clamp, the shear or slip load limits are small enough so that the piping does not meet the 5X weight of water-filled pipe + 250...
