Triple Valve

Triple Valve The operation of the brake on each vehicle is controlled by the "triple valve", so called because it has three functions - to release the brake, to apply it and to hold it at the current level of application.

KICKER"Triple valve in defective order, which throws air brakes into emergency when only a service application is intended, or sometimes by a bump of the train ...

Also called a triple valve ABD Valve An improvement of the AB Valve that features a quick release. ABDW Valve An improvement of the ABD Valve.

See also: Train, Locomotive, Operation, Signal, Freight car