This standard covers the following types of electrical high-density polyethylene (HDPE) conduit. EPEC-A?C HDPE conduit designed for applications below ground@ either concrete encased applications or direct burial. This type represents the nominal dimensions for HDPE conduit as specified by ASTM D 3035@ SDR 17 and UL 651B. EPEC-B?C HDPE conduit designed for applications below ground@ either concrete encased applications or direct burial. This type represents the nominal dimensions for HDPE conduit as specified by ASTM F 2160@ SDR 13.5. The two and one-half inch trade size is taken from UL 651B. EPEC-40?C HDPE conduit designed for application below ground@ either concrete encased applications or direct burial. This type represents the nominal dimensions for HDPE conduit as specified by ASTM F 2160@ Schedule 40. EPEC-80?C HDPE conduit designed for applications below ground@ either concrete encased applications or direct burial. This type represents the nominal dimensions for HDPE conduit as specified by ASTM F 2160@ Schedule 80. NOTE?CThe values stated in U.S. customary units are to be regarded as the standard.