49 C.F.R. § 230.50 Time of testing.
Title 49 - Transportation
All safety relief valves shall be tested, and adjusted if necessary, under steam at every 92 service day inspection, and also whenever any irregularity is reported.
Title 49: Transportation
PART 230—STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS
Subpart B—Boilers and Appurtenances
Safety Relief Valves
§ 230.50 Time of testing.