49 C.F.R. § 236.553 Seal, where required.
Title 49 - Transportation
Seal shall be maintained on any device other than brake-pipe cut-out cock (double-heading cock), by means of which the operation of the pneumatic portion of automatic train-stop or train-control apparatus can be cut out.
Title 49: Transportation
PART 236—RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES
Subpart E—Automatic Train Stop, Train Control and Cab Signal Systems
Rules and Instructions; Locomotives
§ 236.553 Seal, where required.