Railway freight brake retainer valve device

A brake cylinder pressure retainer valve device for a railway car having a "direct" exhaust position, a "slow direct" exhaust position, and a "high pressure" retention position. A cavity in the retainer valve body has a central pedestal on which a rotary type disc valve is mounted. The disc valve has different sized ports via which pressure is connected from an inlet port (in the retainer valve body) to an outlet port depending upon the position of a manually operated handle to which the disc valve is connected. One such port is associated with a spring loaded check valve to provide the "high pressure" retention of the brake cylinder exhaust pressure. A laterally flexible sidewall of the disc valve member is formed with 180 DEG opposed detent tabs for engagement with a plurality of detent grooves formed in the sidewall of the valve body within which the disc valve is operably disposed, the detent grooves being positioned to receive the detent tabs in accordance with the respective openings in the disc valve for alignment thereof with the inlet port in the different brake cylinder exhaust control positions. Plastic is the material of choice for this brake cylinder pressure retainer valve device.