This Standard covers coilable@ smooth-wall@ continuous length conduit with a circular cross section. The conduit is Schedule-40@ Schedule-80@ EPEC-A@ or EPEC-B High Density Polyethylene (HDPE) in trade sizes 1/2 (16) ?C 6 (155). This product is intended for installation in accordance with the National Electrical Code@ NFPA 70. The values in parentheses are metric trade designators of conduit. The designations Schedule-40@ Schedule-80@ EPEC-A@ and EPEC-B refer to conduit having specific outside diameters and wall thicknesses. This product is for aboveground use where encased in not less than 2 inches (51 mm) of concrete and for underground use by direct burial or encasement in concrete. A product that contains features@ characteristics@ components@ materials@ or systems new or different from those covered by the requirements in this standard@ and that involves a risk of fire@ electric shock@ or injury to persons shall be evaluated using the appropriate additional component and end-product requirements to determine that the level of safety as originally anticipated by the intent of this standard is maintained. A product whose features@ characteristics@ components@ materials@ or systems conflict with specific requirements or provisions of this standard shall not be judged to comply with this standard. Where appropriate@ revision of requirements shall be proposed and adopted in conformance with the methods employed for development@ revision@ and implementation of this standard.