49 C.F.R. § 230.42 Location of gauges.
Title 49 - Transportation
Every boiler shall have at least one steam gauge which will correctly indicate the working pressure. The gauge shall be positioned so that it will be kept reasonably cool and can conveniently be read by the engine crew.
Title 49: Transportation
PART 230—STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS
Subpart B—Boilers and Appurtenances
Steam Gauges
§ 230.42 Location of gauges.
