CFR › Title 46 › Part 52 › §52.25-346 CFR §52.25-3Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkFeedwater heaters must meet the requirements in PFH-1 of Section I of the ASME BPVC (incorporated by reference; see § 52.01-1).