ABDX-C SERVICE GRADUATING VALVE AND SLIDE VALVE AND SLIDE VALVE DESIGN INCORPORATING ACCELERATED APPLICATION VALVE (AAV) FUNCTIONALITY.

摘要

A main piston assembly for a service valve portion of a brake control valve for a railway vehicle braking system includes a service graduating valve and a service slide valve. The graduating valve includes a first side having a porting pattern defined therein. The service slide valve includes a graduating valve seat having a porting pattern in a first side and a service slide valve face having a porting pattern in an opposing second side. The porting patterns of the first side of the graduating valve, the graduating valve seat, and the service slide valve face are configured to perform an accelerated application valve function venting brake pipe pressure to atmosphere and to direct pressure from an accelerated release reservoir to the service graduating valve to discontinue the accelerated application valve function when a slight brake pipe over-reduction condition exists.