Valves for maintaining brake cylinder pressure in freight car brake equipment are provided. A valve includes a first diaphragm defining a first side and a second side, and a second diaphragm defining a first side and a second side. The valve further includes a first port for receiving pressure from one of an emergency reservoir or a control volume, the first port in fluid communication with the first side of the first diaphragm; a second port for receiving pressure from a brake pipe, the second port in fluid communication with the second side of the first diaphragm; and a third port for receiving pressure from a brake cylinder, the third port in fluid communication with the second side of the second diaphragm.

An automatic retainer valve includes a body defining a piston passageway and at least one piston positioned within the piston passageway, a brake pipe and reference volume in fluid communication with a first end of the valve, a brake cylinder in fluid communication with a second end of the valve, and an exhaust port defined in the body and positioned between the first and second ends of the valve. Pressurized fluid may be vented from the brake cylinder via the exhaust port upon a brake cylinder pressure exceeding a reference volume pressure. The brake cylinder pressure may push the at least one piston towards the first end of the valve until the brake cylinder pressure equalizes with the reference volume pressure.

An automatic retainer valve includes a body defining a piston passageway and at least one piston positioned within the piston passageway, a brake pipe and reference volume in fluid communication with a first end of the valve, a brake cylinder in fluid communication with a second end of the valve, and an exhaust port defined in the body and positioned between the first and second ends of the valve. Pressurized fluid may be vented from the brake cylinder via the exhaust port upon a brake cylinder pressure exceeding a reference volume pressure. The brake cylinder pressure may push the at least one piston towards the first end of the valve until the brake cylinder pressure equalizes with the reference volume pressure.

A pneumatic pressure control valve for a brake control system of a rail vehicle having at least three pressure chambers supplied with compressed air and are disposed in a housing of the pressure control valve, a first pressure chamber sealed by a piston and by a valve seat arranged on a tappet, subjected to a braking pressure and fluidically connected to a second pressure chamber via a conduit in the tappet to relieve pressure, a further third pressure chamber supplied with a supply pressure, arranged between the two pressure chambers and the sealing between the third pressure chamber and the second pressure chamber is achieved by a flat membrane arranged in the third pressure chamber and which enables the tappet to be axially displaced, the flat membrane has a circular opening arranged substantially centrally to provide a check function and through which the tappet extends in the axial direction.

A modular EAB system that reduces the number of individualized modules but provides the desired functionality using a configuration module that is coupled to a plurality of brake system control modules and has a receptacle interface configured to engage a series of modular sections that can be selected from a variety of options to perform dedicated air brake functions. The dedicated air brake functions included comprise brake pipe cutout, equalizing reservoir backup, brake pipe emergency, automatic flow calibration, dead engine regulator, dynamic brake interlock, emergency limiting valve regulation, dynamic brake interlock and emergency limiting valve regulation, 20 pipe back up, and brake cylinder cutout.

An electronically controlled pneumatic (ECP) overlay control valve can selective switch between a conventional pneumatic mode and an ECP mode. In ECP mode, the overlay control valve shunts the brake cylinder pressure of the pneumatic control valve which allows a relay valve to build or exhaust pressure in the brake cylinder in response to an electronically controlled apply/release circuit. In conventional pneumatic mode, the overlay control valve disconnects the relay valve and allows a conventional pneumatic control valve to control the pressurization and exhausting of the brake cylinder.

A sequencing valve for an automatic parking brake. The sequencing valve has a housing with a first port for communication with a source of a brake pipe pressure, a second port for communication with an exhaust, and a third port for communication with a brake pipe pressure input of an automatic parking brake. A valve body in the housing is moveable to either isolate the brake pipe pressure from the input to the parking brake, or couple brake pipe pressure to the input so that the parking brake may be released. A pilot is interconnected to the valve body for moving the valve body from the first position to the second position and can be driven by a charging and partial release of brake pipe pressure, charging of brake cylinder pressure, or a pneumatic signal provided by an electrical or a pneumatic control valve.

Valves for maintaining brake cylinder pressure in freight car brake equipment are provided. A valve includes a first diaphragm defining a first side and a second side, and a second diaphragm defining a first side and a second side. The valve further includes a first port for receiving pressure from one of an emergency reservoir or a control volume, the first port in fluid communication with the first side of the first diaphragm; a second port for receiving pressure from a brake pipe, the second port in fluid communication with the second side of the first diaphragm; and a third port for receiving pressure from a brake cylinder, the third port in fluid communication with the second side of the second diaphragm.

A sequencing valve for an automatic parking brake. The sequencing valve has a housing with a first port for communication with a source of a brake pipe pressure, a second port for communication with an exhaust, and a third port for communication with a brake pipe pressure input of an automatic parking brake. A valve body in the housing is moveable to either isolate the brake pipe pressure from the input to the parking brake, or couple brake pipe pressure to the input so that the parking brake may be released. A pilot is interconnected to the valve body for moving the valve body from the first position to the second position and can be driven by a charging and partial release of brake pipe pressure, charging of brake cylinder pressure, or a pneumatic signal provided by an electrical or a pneumatic control valve.

The present disclosure provides an emergency valve, including: a valve body (10) comprising an emergency cavity (11), a pressure increasing cavity (12) and an inflation cavity (13) which are spaced apart from one another, wherein an extension direction of the pressure increasing cavity (12) is the same as an extension direction of the inflation cavity (13); an air inlet of the emergency cavity (11) is in communication with a train pipe (71); the pressure increasing cavity (12) is provided with a first communication port, a second communication port and a relief port; the relief port of the pressure increasing cavity (12) is located between the first communication port of the pressure increasing cavity (12) and the second communication port of the pressure increasing cavity (12); the first communication port of the pressure increasing cavity (12) is in communication with a brake cylinder (72); and the second communication port of the pressure increasing cavity (12) is in communication with the emergency cavity (11). The device increases the inflation speed of the train pipe, and achieves the aim of saving energy by utilizing the pressurized air in the brake cylinder.