This happened while I'm playing the Omnifactory mod pack. It appears that snow would accumulate on all kinds of high speed pipes, which shouldn't happen since they are transparent.

Also it would be much nicer if those high speed pipes could have those 'structural support' just like what normal pipes do. (I mean the little 'legs' that connect the pipes to adjacent block.) That would make them much much more nice. (If that adds too much work, it's OK to not add it :D)
Thanks for the great mod!