US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter I — PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 179 — SPECIFICATIONS FOR TANK CARSSubpart D — Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW, 115AW, and 117AW)179.220-2449 C.F.R. § 179.220-24Tests of pressure relief valves.Last amended: 2016Year: 2026Length: 38 wordsOfficial source Cite as 49 C.F.R. § 179.220-24 (2026)Each safety relief valve must be tested by air or gas for compliance with § 179.15 before being put into service. [Amdt. 179-9, 36 FR 21343, Nov. 6, 1971, as amended at 62 FR 51561, Oct. 1, 1997]Cross-references to the CFR179.15Previous49 C.F.R. § 179.220-23Next49 C.F.R. § 179.220-25