Culverts and Drainage CSP, HDPE & Concrete Box culverts available for pickup or delivery. We’re here to help farmers, contractors, or Homeowners. Corrugated Steel Pipe (CSP) offers the optimum combination of strength, flexibility and performance. BOSS 2000 is a dual-wall corrugated HDPE with a smooth inner wall, ranging from diameters of 100mm to 900mm. Available in solid, perforated, ASTM, SDR 26, SDR 28, SDR 35, and BDS. For the collection of waste and stormwater. Find a range of 4″ PVC Sewer Pipe Fittings online, along with tons of fittings in all sizes in stock on location. Municipal Castings & Frame and Grates are available in a range of OPSD sizes to collect and remove water & debris. Industry-leading Super Box Culverts. Consisting of stacked top and bottom boxes, designed for increased flow.