LHB air brake system used in lhb coahces.pdf

An air brake system is a type of braking mechanism commonly used in heavy-duty vehicles such as trucks, buses, and trains. It utilizes compressed air to create the necessary force to engage the brakes, offering advantages in terms of reliability, efficiency, and safety, especially under high-load conditions.

Components and Operation
**1. Air Compressor:
The air brake system begins with an air compressor, which is typically driven by the engine. Its primary function is to compress ambient air and deliver it to the air reservoirs. The compressor maintains a constant supply of compressed air to ensure that the brakes are responsive when needed.

**2. Air Reservoirs:
Compressed air is stored in air reservoirs or tanks. These reservoirs hold the compressed air under pressure and release it when required. They act as a buffer, ensuring a steady supply of air to the brake system even if the compressor is temporarily unable to keep up with demand.

**3. Air Dryer:
Air dryers are essential components that remove moisture and contaminants from the compressed air before it enters the reservoirs. Moisture and particulates can cause corrosion and wear on the brake system components, so the air dryer helps in maintaining the efficiency and longevity of the system.

**4. Brake Pedal and Control Valve:
The driver controls the air brake system using the brake pedal. When the brake pedal is pressed, it activates a control valve that regulates the flow of compressed air to the brake chambers. This valve modulates the amount of air sent to the brakes based on how much braking force is required.

**5. Brake Chambers:
Each wheel or axle typically has its own brake chamber. The brake chamber contains a diaphragm that moves when compressed air is applied. This movement pushes against the brake mechanism (such as brake shoes or discs) to create the friction needed to slow down or stop the vehicle.

**6. Slack Adjusters:
Slack adjusters are mechanisms that automatically adjust the distance between the brake shoes and the drum to maintain optimal braking performance. They compensate for brake wear over time, ensuring that the brakes remain effective and that the system does not become inefficient.

**7. Spring Brakes:
Spring brakes, also known as emergency brakes, are a crucial safety feature. They use powerful springs to apply the brakes in the event of a sudden loss of air pressure. Spring brakes are designed to engage automatically if the system detects a significant drop in air pressure, providing a fail-safe mechanism to bring the vehicle to a stop.

1. AIR BRAKE SYSTEM
Of 
LHB COACHES

2. COMPONENTS OF BRAKE SYSTEM
(
Mainly Brake Equipment's are placed at four locations:
(
Pressure tanks (Air reservoirs):
(
Main  reservoir -One 125L for brake application 
(Protected by check valve)  
(
Auxiliary reservoir - One75L for toilets & brake 
(Capacity of Both125L and 75L available for brake application)  (
Controlled reservoir -One 6L 

3. CONSTITUENTS OF BRAKE SYSTEM
Brake control panel 
Test fittings 
Feed Pipe 
Brake Pipe 
Control Reservoir 
Brake Cylinder 

4. Pressure switch to operate WSP (connected to FP):
At 1.3 Bar-Off
At 1.8 Bar-On
Filters for BP and FP
Isolating cocks for:
1.
Feed pipe
2.
Toilet
3.
Bogie-1 and Bogie-2
4.
Isolating cock for emergency brake (ACP system).

5. Choke -2mm in Brake indicator line:
(Fitted in connection to the brake indicators to minimize 
the loss of brake cylinder pressure in the event of  
indicator failure)

6. (
Distributor Valve with intermediate flange:
(
Relay valve is directly mounted. 
(
It has a quick release device mounted to the valve body. 

7. A
Equipment's on Bogies:
A
Hose connections:
A
4 Nos  (To Connect BC line to each axle)
A
8 Nos  (Bifurcates BC to each brake cylinder) 
A
Brake caliper unit:
A
Qty required: 8 Nos (4 nos per bogie-2 LH and 2 RH)
A
Suitable for fitting UIC type 200x2 pads of thickness 35 mm
A
Calipers shall give effective brake radius of 247mm
A
Lever Ratio: 2.17 for all except  2.48 for ACCN/SG and 
Power car

8. A
Brake cylinder :
A
Compact construction
A
Auto slack adjuster - Brake shoe clearance due to wear 
corrected automatically by single acting slack adjuster.
A
No manual adjustment to make after brake pad 
replacement.
A
Piston travel:  21 mm (max)
A
Slack capacity:  160mm (max)
A
Cylinder size: 10 inches
A
Max BC pressure:  3.0 kg/cm
2

9. A
Brake pads -35mm thick  and 200 Cm
2 
(Composite type): 
A
Quantity per coach: 32 Nos. (16 LH - 16 RH)
(16 on each bogie-2 on each caliper)
A
Wear limit -28mm max.
A
Brake Disc: 
A
Quantity per coach -8 Nos (two per axle)
A
Disc dimensions -640X110
A
Material:  Grey cast iron
A
Speed censor cable with pole wheel (80 teeth):
A
4 Nos. -One per axle)
A
Gap between speed 
Sensor and pole wheel  - 0.9 to 1.4 mm

10. Emergency Brake system 
A
In each compartment emergency pull boxes are installed, which 
operates through emergency brake valve. A
If handle of pull box moved then the brake valve exhaust the BP via a 
large orifice up to 2 bar after this it stop to ven t. A
Emergency brake light outside the coach will be activated by using 
the pull box, which is equipped  with an electrical switch.

11. A
Equipment on car body:
A
Angle cocks 8 Nos. (Old), 4 (New)
(At coach ends on BP and FP Pipes-FP and BP bifurcated 
into two branches  to make coupling between two 
adjacent coaches)
A
Brake and feed pipe coupling 8 Nos. (4BP and 4 FP) Old
4 Nos. (2BP and 2 FP) New
A
Brake application and release indicators 4 Nos (2per Bogie-
2 on each side of the coach) A
Antiskid valve /Dump valve              4 Nos
A
2 per Bogie or One per Axle
A
Terminal Box for speed sensor cable - 4 Nos
A
Terminal Box for Antiskid valve - 4 Nos

12. A
Emergency Brake accelerator -1 Nos. 
A
Mounted on brake pipe. If the BP drop rate is 1.5 kgf/sq. 
cm or more within 3 seconds, brake accelerator 
activates.
A
Brake accelerator designed to operate during 
emergency brake application and ACP only.
A
Two 28mm pipes running through the coach for 
BP and FP
A
DV is activated by BP pressure increase or reduction for 
brake application and release 

13. PIPES AND PIPE FITTINGS
A
Pipes used:
A
28mm for BP and  FP Thickness =1.5mm
A
10mm for emergency
and pressure gauges  Thickness = 1mm
A
18mm for brake 
cylinder pipes (BC line) Thickness =1.5mm

14. PIPE FITTINGS-BITE TYPE 
A
Cutting ring ensures sealed joint.
A
Designed for metric tubes i.e. OD of pipe is 
important

15. A
Precautions:
A
Fittings are to be handled with care. Bite edge to be 
protected
A
Do not use hand cutters. Edge of should be straight
A
Fix pipes line with clamps.
A
Non standard materials or tolerances lead to incorrect 
fittings.
A
The tools & lubricants recommended by EO ensure safe 
assembly.

16. A
Advantages:
A
Sealing capability
A
High pressure resistance
A
Durability
A
Bite control
A
Assembly cost
A
Integrated preassembly tool
A
Reliability
A
Make-up
A
No phantom leaks

17. ADDITIONAL EQUIPMENT FOR HAND BRAKE
A
Hand brake indicators 2 Nos (One on side of 
Power car/Guard van)
A
Cheek valve 1 Nos. (In feed pipe)
A
6 Ltrs. Air cylinder- 1 Nos. (Mounted on ABP)
A
Flexi ball cable- 1 Nos.

18. ADDITIONAL EQUIPMENT FOR HAND BRAKE
A
Pressure gauges- 3 Nos.
A
FP
A
BP
A
BC
A
Brake caliper units- 2 Nos.
(of different type suitable for hand brake flexible  
connections)
A
Connecting part for flexible ball- 2 Nos.

19. A
Less thick stainless steel pipes (Metric pipes).
A
No threads/Flange joints -Bite Type fittings used.
A
No brake rigging
A
Wheel slide protection unit -Take cares wheel flattening 
A
Centralized control  -Complete coach.
A
Braking on Axle mounted disc  -No wheel wear due to braking.
A
Brake accelerator -for sharp reduction of BP 
pressure in complete train set. A
DV with relay - Ensures brake application time 
and release. A
All Pipes below under frame -Ease for maintenance.
A
Release rod -Improved design (Properly 
supported A
Brake Indicators -RED means  brake applied
-Green means brake released
Feature of axle mounted disc brake system with WSP
(compared with conventional brake system)

20. BRAKE CONTROL PANEL AND INDICATOR UNIT
Brake indicator
Brakecontrolpanel
DV
ReleaseRod
Reservoir
Testfittings
Isolatingcocks

21. SAB WABCO CONTROL 
PANEL

22. Axle mounted brake disc
Brake calipers
Brake Cylinder
Brake Pads

23. SPEED SENSOR CABLE WITH TERMINAL BOX Cable sensor
Terminal Box
Pole Wheel inside the cover

24. EMERGENCY PULL BOX

25. BRAKE ACCELERATOR

26. WSP ELECTRONIC UNIT

27. Principle of Antiskid System

28. PRINCIPLE OF BITYE TYPE FITTING

29. Tightening of the bite fitting

30. Anti skid/ Dump valve assembly design.

32. Knorr Air Brake Panel

33. FaiveleyAir Brake Panel

34. Air strainer/Filter

35. Division of FP and BP pipe joints in two
parts (Old), replaced in new design

36. Wheel shelling marks

37. Brake cylinder
Pressure pipe connection
Brake caliper unit
Brake disc