Some part numbers in the Ronco book have been earning their keep for decades, and the B-series molding behind the RVB392 is one of them. This is a large-capacity light-duty fresh water tank - a 142 pound molding in translucent natural polyethylene - that keeps getting specified because its particular footprint keeps solving bays that the common shapes cannot. Ronco has been molding water tanks in Tustin, California since 1974, and a catalog this deep is the accumulated answer to every odd compartment its customers ever brought through the door.
The resin is FDA compliant, so the tank is rated for drinking water, and the natural translucent wall shows the water level without any instrumentation. Light-duty is Ronco's wall schedule for supported, in-vehicle fresh water service - the right spec when the tank sits on a bay floor rather than hanging exposed underneath.
What you are really buying is a blank molding plus a fitting layout of your own design. Ronco spin-welds or threads every port per order, located to your marks. Print the technical drawing below, plot your fill, vent, and outlet positions against your actual plumbing runs, and lock it in with the fitting planner on this page. Then check your chassis math: water is 8.34 pounds per gallon, and a tank this size carries a meaningful load when full.
Compare against the stock sizes in the RV water tank category, survey the full Ronco Plastics line, and price the ship with the freight estimator. OneSource Plastics is an authorized Ronco Plastics dealer.