Comeng Brake Unit Flashcards
What are the components of the brake unit?
(9 answers)
7 step relay valve (EP brake)
Restricted Application Magnet Valve (M
Cars only) RAM
Variable load valve
Hand release wire
Restricted application limiting valve and ball check valve RALV & BALL CH.
Dump valve
Bypass check valve
Triple valve
7, T RRR VB HD
What is the purpose of the 7 step Relay valve
Converts electrical code signals into 7 equal steps of air pressure (EP)
Controls flow of air from MR on that car to the Brake Cylinders
Purpose of Restricted application magnet valve
• Prevents simultaneous application of EP braking when on Rheo on M cars only
• a small holding pressure in BCyl. during Rheo braking on Westcodes only
What is the purpose of the VLV (Variable load Valve)
Monitors air pressure in air suspension system,
to allow for braking requirements depending on weight on train
Purpose of RALV & Ball check valve
Gives us 10% more pressure on brake Cylinders (1 on each bogie - when auto air braking)
Adjusts brake cylinder pressure during rheo braking to a holding pressure
Purpose of the Dump Valve
Dumps air from Auxiliary res
to release brake (happens automatically)
* aids in prevention of sticking brakes
* reduces air pressure in Aux. res. When EMY brakes applied over top of EP braking
Release ensuring valve
Removes small amount of air pressure (14 kPa) from AUX res in R & R when operating EP brake
(ensures triple valve is in released position)
Purpose of Bypass check Valve
During EP braking, air passes through the triple valve to Brake Cyl., but when this cannot occur, Bypass check valve allows MR air to reach brake cylinders
Purpose of the Triple valve
Controls flow of compressed air from the
- BP to AUX res (to charge the brake)
- Aux Res to BC (to apply brake)
- B.Cyl. To atmosphere (to release brakes)
What is the purpose of the hand release valve
Provides manual release of brake cylinder pressure on during brake defects or maintenance
