BRAKE CYLINDER PRESSURE MAINTENANCE VALVE FOR FREIGHT CAR BRAKE EQUIPMENT AND FREIGHT CAR BRAKE SYSTEM COMPRISING SUCH A VALVE

摘要

A valve (300) for maintaining brake cylinder pressure in freight car brake equipment and a freight car brake system comprising such valve (300) are provided. The valve (300) includes a first diaphragm (302) defining a first side (310) and a second side (312), and a second diaphragm (304) defining a first side (314) and a second side (316). The valve (300) further includes a first port (320) for receiving pressure from one of an emergency reservoir (ER,132) or a control volume (380), the first port (320) in fluid communication with the first side (310) of the first diaphragm (302); a second port (322) for receiving pressure from a brake pipe (BP,114), the second port (322) in fluid communication with the second side (312) of the first diaphragm (302); and a third port (324) for receiving pressure from a brake cylinder (BC,120), the third port (324) in fluid communication with the second side (316) of the second diaphragm (304).