AIR BRAKE SYSTEM ( I.R )

AIR BRAKE SYSTEM

            In Air Brake system compressed air is used for operating the brake system. The locomotive compressor charges the feed pipe and the brake pipes throughout the length of the train. The feed pipe is connected to the auxiliary reservoirs and the brake pipe is connected to the brake cylinders through the distributor valve. Brake application takes place by dropping the pressure in the brake pipe. The schematic arrangement of the brake equipment is shown as Fig 1.

Types of Air Brake System:-

1) Direct Release System :- (100% creation & drop of pressure)

In direct release system, the brake cylinder pressure cannot be reduced in steps by increasing the brake pipe pressure in steps during release. The brakes are released immediately, as soon as releasing of brakes is initiated.

2) Graduated Release System:-

In this system the brake cylinder pressure can be reduced gradually in steps in proportion to the increase in brake pipe pressure.

There are two types of Graduated Release Air Brake:-

1) Single Pipe Air Brake System.

2) Twin Pipe Air Brake System.

1) Single Pipe Air Brake System: -

There is only one pipe called brake pipe running from loco to the brake van in order to get continuity of air for the application & release of brakes.

i) At present running in goods stock.(Except latest developed BOX-N HL, BCN HL wagons)

ii) Releasing time is more 45 to 60 sec.

2) Twin Pipe Air Brake System :-

i) In addition to brake pipe, there is one more pipe called feed pipe , running loco to the brake van to charge the auxiliary reservoir continuously to 6 kg/cm2.At present running in coaching stock and also in latest developed BOX-N HL, BCN HL wagons)

ii) Releasing time is less 15 to 20 sec

MAIN COMPONENTS OF AIR BRAKE SYSTEM(SINGLE PIPE)

1) Brake pipe – dia. 32 mm (for goods) & Pressure 5 kg/cm2.

2) MU washer

3) Palm Coupling

4) Air Hose (Length:660 mm)

5) Cut Off Angle Cock

6) Grip Seal Joint

7) Branch Pipe (Dia.: 20 mm)

8) Isolating Cock

9) Dirt Collector

10) Common Pipe Bracket

11) Intermediate Piece

12) Distributor Valve

13) Control Reservoir

i) 6 liter (Goods): 5 kg/cm2

ii) 9 liter (Coaching): 5 kg/cm2

14) Auxiliary Reservoir

i) 100 liter (Goods): 5 kg/cm2

ii) 200 liter (Coaching): 6 kg/cm2

15) Manual Release Handle

16) Isolating Handle of DV

17) Drain Cock in DV

18) Branch Pipe for BC

19) Isolating Cock for BC

20) Brake Cylinder Dia – 355 mm (Pressure max. 3.8 ± 0.1 kg/cm2)

WORKING PRINCIPLE

The different processes involved in working :-

A)     Charging

B)      Application

C)      Release

v  Under normal conditions the Brake pipe is charged with 5kgf/cm2 from the locomotive .The  Control Reservoir and the Auxiliary Reservoir are charged with 5kgf/cm2 and 6kgf/cm2 respectively from the B.P through Distributor Valve.

v When Brake Pipe is charged at 5kgf/cm2 the Brake Cylinder is connected to exhaust through Distributor Valve in order to keep the Brake in Released position fully.

v Whenever the Brake Pipe pressure is reduced below the C.R (Control Reservoir) pressure, the Distributor Valve connects the Auxiliary Reservoir with the Brake Cylinder and the Air from Auxiliary Reservoir is sent into the Brake Cylinder to Apply the Brake.

v Whenever the Brake Pipe Pressure is equal to the C.R Pressure , the D.V disconnects the B.C from A.R and in turn connects the B.C with exhaust for the release of Brakes fully.