While it has been possible to get a variety of colors, including clear acrylic tube, I stumbled upon clear schedule 40 pvc pipe. It is completely compatible with the off the shelf fittings available in white and gray at any Home Depot / Lowes etc, as well as having a variety of clear fittings available as well. It is made for situations where they want to visually monitor the flow.
A PDF of the product is available at:
An additional site to reference with a larger line can be found at: