49 C.F.R. § 230.74 Time of cleaning.
Title 49 - Transportation
All valves in the air brake system, including related dirt collectors and filters, shall be cleaned and tested in accordance with accepted brake equipment manufacturer's specifications, or as often as conditions require to maintain them in a safe and suitable condition for service, but not less frequently than after 368 service days or during the second annual inspection, whichever occurs first.
Title 49: Transportation
PART 230—STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS
Subpart C—Steam Locomotives and Tenders
Brake and Signal Equipment
§ 230.74 Time of cleaning.
