Air Brakes and Train Handling Rules - Alaska Railroad

67 Car Equipment and Components67.13.1 Freight Cars Equipped With A-1 ReductionRelay ValveThe following freight cars are equipped with the relay valve:• Cars with AB or ABD control valves and more than 75 feet ofbrake pipe between hose couplings• Cars with ABDW control valves and more than 100 feet of brakepipe between hose couplingsNOTE: Cars with ABDW control valves having between 75and 100 feet of brake pipe have a No. 8 vent valve added.67.14 Automatic Slack AdjusterThe automatic slack adjuster maintains piston travel limits as brakeshoes, brake rigging, and wheels wear.67.15 Piston Travel LimitsThe following information identifies the piston travel limits for bodymounted air brake cylinders, truck mounted air brake cylinders, or aTTOX AIR ACTUATOR single wheel truck air brake system.67.15.1 Body Mounted Air Brake CylindersThe cylinder diameter size is cast into the cylinder housing. On12-inch cylinders, the housing is 90 degrees to the piston rod. Oncylinders less than 12 inches, the housing is tapered.June 1, 1996 ARRC Air Brakes and Train Handling Manual 67-15