Purga de Cilindros

Cuando se deja de admitir vapor en los cilindros, se enfrían rápidamente. Esto es porque están separados de la caldera y de la cámara de combustión. El vapor en los cilindros se condensa entonces de nuevo en agua rápidamente. Como el agua no es compresible, a diferencia del vapor, si se acumula una cantidad suficiente en los cilindros y es empujada por un pistón, puede romper los cilindros y provocar un fallo catastrófico del tren motriz.

For this reason there are cylinder cocks. They are operated by a valve from inside the cab, allowing water to be released from the cylinders. As some of the steam from the cylinder is lost while the cylinder cocks are open, acceleration is reduced. Typically, the drivers open cylinder cocks for a few seconds after being stationary for some time.

Cylinders can also fill with water in a process called priming. This is the case of the boiler having too much water, or running the vehicle with the cutoff set in the opposite direction, causing water to overflow into the cylinders.

See also: Mechanical Powertrain Damage, Water Level, Cutoff