66699 ⎘
Construction arrangement, or operation of valves incorporated in power brake systems and not covered by groups or; Application and release valves; Triple or other relay valves which allow step-wise application or release and which are actuated by brake-pipe pressure variation to connect brake cylinders or equivalent to compressed air or vacuum source or atmosphere controlled by three fluid pressures with a quick braking action; Railway control or brake valves with evacuation of air to a reservoir, to the atmosphere or to the brake cylinder with one slide valve