The ADS® N-12® ST IB (per AASHTO) specification document covers pipe requirements, joint performance, fittings, material properties, installation information, & BABA information.

Pipe requirements for the N-12 ST IB (per AASHTO) include a smooth interior and annular exterior corrugations, 4”-10” (100 to 250 mm) pipe shall meet AASHTO M252, Type S or SP, 12”- 60” (300 to 1500 mm) pipe shall meet AASHTO M294, Type S or SP, or ASTM F2306. Manning’s “n” value for use in design shall be 0.012.

Fittings need to conform to AASHTO M252, AASHTO M294, or ASTM F2306. Bell and spigot connections will utilize a welded bell and valley or saddle gasket meeting the soil-tight joint performance requirements of AASHTO M252, AASHTO M294 or ASTM F2306.

Material for pipe and fitting production is high density polyethylene conforming with the minimum requirements of cell classification 424420C for 4”-10” (100 to 250 mm) diameters and 435400C for 12”-60” (300 to 1500 mm) diameters, as defined and described in the latest version of ASTM D3350, except that carbon black content should not exceed 4%. The 12”-60” (300 to 1500 mm) pipe material shall comply with the notched constant ligament-stress (NCLS) test as specified in Sections 9.5 and 5.1 of AASHTO M294 and ASTM F2306, respectively.

Installation is in accordance with ASTM D2321 and ADS recommended installation guidelines, with the exception that minimum cover in trafficked areas for 4”-48” (100 to 1200 mm) diameters shall be one foot. (0.3 m) and for 60” (1500 mm) diameter the minimum cover shall be 2 ft. (0.6 m) in single run applications. Backfill for minimum cover situations shall consist of Class 1 (compacted), Class 2 (minimum 90% SPD) or Class 3 (minimum 95% SPD) material. Maximum fill heights depend on embedment material and compaction level; please refer to Technical Note 2.01.

A Pipe Dimensions table is included for reference.

N-12 ST IB Pipe (per AASHTO) is manufactured in accordance with AASHTO M252, AASHTO M294 or ASTM F2306, and complies with the requirements in the Build America, Buy America (BABA) Act.