Gravity sewer piping consists of a large network of underground mains that rely on gravity to convey storm water and wastewater from homes and businesses to a central treatment plant. In route, the gravity must allow a self-cleansing flow velocity so that no particles accumulate in the line. In areas where such a flow cannot be maintained, pumps must be installed to generate necessary flow through lines that are called force mains.
AMERICAN ductile iron pipe has long been a popular choice for gravity sewer systems, which typically consist of a large sewer main running along a major highway that is connected to smaller lines in neighborhoods and even smaller lines leading from individual residences and businesses. All these lines run from manhole to manhole and are installed at a steady, even slope. When you see a manhole cover that says “Sanitary Sewer,” there’s a line like this underneath.
Ductile iron’s superior strength makes it ideal for deep trenches and installations in areas of high water table, and the larger inside diameter of AMERICAN ductile iron pipe (compared with comparably sized competing materials), is conducive to higher flow velocity and carrying capacities. AMERICAN’s bottle-tight joints ensure that roots and other foreign matter don’t get into the pipe, that groundwater does get inside the pipe, and that waste materials do not escape into the environment.
In hotter and flatter areas where the slope is slight and the flow is very slow, it is often necessary to line the pipe with a grease and corrosion-resistant interior lining such Protecto 401 ceramic epoxy lining.
In those cases where a gravity sewer larger than 64 inches is required, AMERICAN’s spiral-welded steel pipe with Ceramapure epoxy lining is an ideal solution. The strength and flexibility of steel matches that of ductile iron, and a welded or O-ring joint ensures the integrity of the flow.