Eight inches. That is the entire height of the B529, and it still holds 34 gallons by running 44 inches long and 25 inches wide. Ronco molds a lot of low tanks; this is one of the lowest usable ones in the marine book, and it turns the void between floor and hull skin - space most builders write off - into a third of a hundred gallons of tankage.
As a B-series blank it is dual-role. Fresh water service gets FDA-approved potable polyethylene and your choice of supply fitting locations; gray or black service gets the same molding with waste fittings. Because there are only 8 inches of liquid column, fitting placement is the difference between a tank that drains and a tank that always holds a stubborn few quarts - so print the drawing below, think about where the low corner will be at resting trim, and lay the ports out in the on-page fitting planner. Ronco spin-welds or thread-installs them to your marks.
The B529 ships at 90 lb - heavy for 34 gallons, because a 44 x 25 inch roof needs thick walls to keep from sagging when someone stands on the floor above it. Full, add about 284 lb of water. Support the whole underside; a pancake tank must never bridge. Molded in Tustin, California since 1974.
See what else fits a flat void in RV holding tanks and boat tanks, or start at the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B529 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
