Introduced in 1987, dual wall N-12® Pipe, with its smooth interior wall and corrugated exterior, offers exceptional hydraulics and strength. Built using application specific HDPE, dual wall N-12® corrugated Pipe also provides superior corrosion and abrasion resistance. This makes it an excellent alternative to reinforced concrete (RCP) and corrugated metal Pipe (CMP). N-12® Pipe is available in soiltight, watertight and plain end, all of which offer joint options of bell and spigot design, gasket, bell wrap or pressure-rated 10.8 psi coupler.