USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Pipeline Safety: Standards Update-PPI-TR 4

Direct final rule (DFR); confirmation of effective date.

PHMSA is confirming the effective date for the DFR that appeared in the Federal Register on July 1, 2025. The DFR amended PHMSA's regulations to incorporate by reference the updated industry standard Plastic Pipe Institute (PPI) Technical Report (TR)-4, "PPI HSB Listing of Hydrostatic Design Basis (HDB), Hydrostatic Design Stress (HDS), Strength Design Basis (SDS), Pressure Design Basis (PDB) and Minimum Required Strength (MRS) Ratings For Thermoplastic Piping Materials or Pipe."

View PDF