The driver's brake valve is a complicated valve system for controlling the compressed air brake of a railway vehicle. Depending on its setting, it controls whether the brake pipes of a compressed air brake are evacuated and thus whether braking is applied or maintained; or if the brake pipes are connected to a compressed air reservoir, it controls whether the brakes are released again or remain released.

This equipment is found on the footplate

Footplate

The footplate of a steam locomotive is a large metal plate that rests on top of the frames and is normally covered with wooden floorboards. It is usually the full width of the locomotive and extends from the front of the cab to the rear of cab or coal bunker just above the buffer beam. The...

 of locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

s or in the driver's cab of power cars and driving cars in multiple unit's, hence the name.

In the simplest case the position of the lever controls the extent to which the valve opens, how quickly compressed air can be released from the pipes or the reservoir in the braking system.

The setting of modern driver's brake valves controls the dynamic reduction of the remaining pressure in the brake pipes.

External links

• Driver's brake valve