Hal -

I agree that the NEC doesn't care about conduit for data wiring, but I do believe that two lengths of ½" EMT, even if secured at both ends would probably come apart at the coupling soon enough. Between vibration and banging I wouldn't trust them to be secure. ½" Rigid pipe m i g h t hold together but personally, I think unistrut & emt with 2 straps per length of tubing would certainly do the trick. Not too difficult, not too expensive and certainly secure.

Sam

"Where are we going and why are we in this hand basket?"