Is there a lofted single or dual industrial pipe available?

In the Mt. Hood RR I'm modeling there are a large pair of water pipes used to move water from a dam to a power plant downriver that run parallel to the track for about two miles. I've found a fixed piece that would work, but will take a lot of installation time. My feeble old memory recalls a larger dual pipe loft that was a download somewhere, but I'm unable to find it. Any help would be appreciated.