The F3UNISEAL puts a 3 inch pipe straight through a tank wall with nothing but a drilled hole and a rubber grommet. At this diameter - full-size waste and pump-out plumbing - the alternative is a large flanged assembly with a backing nut somewhere you cannot reach, so the uniseal is not just the easy option, it is frequently the only practical one on an installed tank.
The grommet seals by compression against both the tank bore and the pipe surface, and it keeps sealing as the pipe vibrates, flexes, and grows with temperature - movement that works threaded joints loose over the years. It also seats on moderately curved walls where a flat flange never could, which is most of the real estate on a rotomolded tank.
This is Ronco's own hardware, sized against the wall sections of the tanks they have molded in Tustin, California since 1974. The high-capacity holding and waste moldings that take a 3 inch line are in our RV holding tank and boat tank categories, with the full catalog on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
