ADS 12810020IB 12" x 20' Perforated Soil-Tight Dual Wall Storm Drainage Pipe. Available in diameters from 100 to 1500 mm, N-12 pipe is replacing reinforced concrete pipe as a preferred product for storm water applications. The reinforced polyethylene bell of N-12 ST IB pipe minimizes distortion. Chipping and cracking common to concrete pipe bells, is eliminated. Today N-12 ST IB pipe is the best soil tight joint for storm sewers on the market.