Final rule · 2025-19334

Pipeline Safety: Standards Update-PPI-TR 4

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."