Irving, Texas — A new, comprehensive reference guide to the many existing industry high-density polyethylene (HDPE) conduit standards has been published by the Plastics Pipe Institute, Inc. (PPI), a non-profit trade association representing many segments of the plastic pipe industry.

Intended as a ready reference for specifying agencies, utility design engineers and contractors, TN-50:

  • includes details on ASTM, NEMA and UL standards for HDPE conduit;
  • clarifies differences between HDPE water pipe and conduit standards;
  • provides a table for proper selection of standards based on conduit diameter and wall-type;
  • contains a flow chart visually illustrating ways to quickly find relevant standards for a specific application — communications or power; and
  • has multiple sources noted for availability of further assistance.

“Although product standards for HDPE water pipe and conduit may appear similar,” explained Lance MacNevin, P. Eng., director of engineering for PPI’s Power & Communications Division (PCD), “conduit specifications have been specifically developed for the demands of telecomm, power, utility, aerial or underground applications.  Specifying an incorrect standard for HDPE conduit can delay projects, increase costs, or result in an inappropriate material selection.  This new guide is designed to help users avoid those problems. TN-50 will be reviewed by PPI members annually, and updated as required.”

HDPE conduit is used to house and protect electrical power and telecommunications cables.  Benefits, according to the PPI, include availability in long lengths without joints, high strength, flexibility, proven reliability and installation toughness.  HDPE conduit, including Cable in Conduit (CIC), is widely used in trenching, horizontal directional drilling (HDD) and plowing installations.

Technical Note 50 (TN-50), Guide to Specifying HDPE Conduit, is available free on PPI’s website at Additional information can be found online at