A PVC pipe you can see through
This rigid PVC pipe is made to schedule 40 dimensions, but it's transparent, with only a slight blue tint, making it easy to see what's inside it. Built for laboratories, food and beverage processing, sight gauges, pharmaceutical manufacture, hospital use, chemical processing, dry food lines and other applications, the pipe and fittings are made from a clear, virgin grade, PVC compound. The ingredients are non-toxic, conform to FDA food contact standards, and the compound is listed by the National Sanitation Foundation for use with potable water. It doesn't need ties or clamps to hold it upright or level, and may be used with standard schedule 40 fittings of gray or white. The Clear-40 pipe and fittings are non-conductive and flame retardant, with a U.L. rating of 94 VO. It comes in ¼ through 4-inch nominal pipe sizes, and fittings come in 90 and 45-degree elbow, T, male and female adapter, coupler, reducer bushing, and cap fittings styles. Optional configurations include bell-shaped ends, other fitting configurations, longer lengths, and schedule 80 dimensions.
NewAge Industries
http://rbi.ims.ca/4930-576