The Plastics Pipe Institute (PPI) Conduit Division (which Blue Diamond is an active member), has worked with UL (Underwriters Laboratory) to revise the standard for HDPE conduit.
UL 651A dated June 24, 2016 is the new standard date. The significant changes are revised values for conduit stiffness (“crush” testing) in Table 9.3. You can purchase a copy of the standard at: http://ulstandards.ul.com/access-standards/
Blue Diamond is a manufacturer of HDPE conduit, industrial pressure pipe and geothermal in Kentucky. BDI is a WOSB (Women Owned Small Business), and certified HUBZone business. For more information, call 859-224-0415 or email Georgez@bdiky.com.