Pneumatically driven train brake pipe pressure exhaust valve

摘要

A valve device for reducing the brake pipe pressure in a railroad train brake pipe at a location remote from a train locomotive including a pair of valves, a first valve to controllably vent brake pipe pressure from the brake pipe for purposes of service brake applications and a second valve to quickly vent brake pipe pressure from the brake pipe at a relatively high rate for purposes of emergency brake applications, and a pneumatic drive means to open the first valve in response to a controlled supply pressure and open the second valve in response to an emergency supply pressure.