modification for fitment - indian railway · installation lever • fitted between link of leveling...

Modification for Fitment

• With steel spring • With air spring

Modification for Fitment

• Installed at Secondary Stage.

• A FIXED lower spring beam used in place of standard bolster suspension arrangement.

• Primary springs made stiffer.

• Additional air reservoir (40 litres) provided on bogie bolster.

• Leveling Valve, Installation lever etc fitted as per schematic diagram.

Working Principles

• The height monitoring valve (called leveling valve) actuates as per changing loads on vehicle,

– Either getting the compressed air pressure to the rubber bellow or

– Releasing air pressure from bellow to atmosphere.

– The process continues until the original height is restored.

Working Principles

• Normal Condition

No flow of air

Working Principles

• Loaded Condition • Empty Condition

From bellow to atmosphere From Reservoir to bellow

Main Equipments of the System

• Air Spring

• Leveling Valve

• Installation Lever

• Duplex Check Valve

Air Spring

• Contitech make • Firestone make

Air Spring

• Codal life expected : 16 Yrs.

• Manufacturers– M/s Contitech/Germany

– M/s Firestone

– SIL, Kolkata

– Asika Commercial Pvt. Ltd, Kolkata.

Main Parts of Air Spring (Fig. of Firestone Make)

TOP PLATE

BID SKIRT

RUBBER BELLOW

BID RING

EMERGENCY SPRING

PADESTAL ASSEMBLY

BASE PLATE

Main Parts of Air Spring

• Spigot – Part of top plate which connects the air path

for bellow from bolster. Two ‘o’ rings are provided on this spigot.

• Emergency Spring– Made by layers of metal and rubber. The

coach rests on this spring when there is no air, i.e. deflated condition.

• Bellow– Rubber made reservoir which holds the air

column for suspension.

• Base Plate– Lowest part of air spring fitted with Lower

Spring Beam.

Main Parts of Air Spring (Firestone Make)

• Emergency spring: rubber with metallic plate at both ends

–Fitted on pedestal assembly by 4 M10 bolts with 40 kgm torque.

Holes for fixing pedestal assembly

Metal PlateRubber

Main Parts of Air Spring (Firestone Make)

• Emergency Spring– This spring is capable of safety carrying the

affected vehicle (either fully or partially loaded) for minimum 1000km at speed of at least 60KMPH under normal operating conditions without suffering any self damage or any further damage to the air spring which will make them unfit for the further use.

– This situation may arise occasionally in the service of the air springs.

Cleaning & maintenance of Air Spring

• Rubber products can be cleaned with soap and warm water.

• The cleaned articles should be dried at room temperature.

• After a fairly long period of storage (6 to 8 months) the products can be cleaned with a 1.5% sodium bicarbonate solution. Remaining traces of the cleaning fluid should be rinsed off with water.

Cleaning & maintenance of Air Spring

• Solvents such as trichloroethylene, carbon tetrachloride as well as hydrocarbons must not be used for cleaning purposes.

• Sharp-edged objects, wire brushes, emery paper etc. should not be used.

• Rubber- metal bondings are to be cleaned using a glycerin-spirit mixture (1:10).

Tools and components for Air Spring

• Screws,

• Lever,

• Hammer,

• Torque spanner,

• Plastic stick,

• Loctite 243.

• Cloth.

Levelling Valve

Levelling Valve

• Mounted on bolster.

• Heart of the system.

• It’s link is connected with installation lever.

• It has three positions:

– Dead Band Zone

– Charging Mode

– Discharging Mode

• Dead Band Zone

Levelling Valve

• Charging mode • Discharging mode

From Reservoir

To atmosphere

From bellow

To bellow

EXTERNAL LOAD

BOLSTER

AIR SPRING BELLOW

BOGIE FRAME

DECREASAED

FROM 150 LTRS. RESERVOIR

DETAILS WORKING OF LEVELING VALVE

INCREASED

Installation Lever

• Fitted between link of Leveling valve and bogie frame.

• The ball and socket joint at both ends are provided to give flexibility.

• Left and Right hand threads are there at it’s either ends

– to increase or decrease it’s length so that the bellow as well as coach height increases and decreases respectively.

Duplex Check Valve

• Descriptions: – Fitted between two

air springs of the same bogie.

– Pressure differential on DC valve is set at 1.5+0.15 bar.

– Allows air to flow in either direction when pressure differential exceeds.

– Ensures no severe tilt or twist when one bellow burst.

– it remains closed up to the preset differential pressure.

P 1 P 2

AIR SPRING

DUPLEX CHECK VALVE

(P 1 – P2) ≥ (1.5 ± 0.15) kg/cm2

Duplex Check Valve Detail operation

P 1 P 2

AIR SPRING

DUPLEX CHECK VALVE

(P 2 – P1) ≥ (1.5 ± 0.15) kg/cm2

Duplex Check Valve Detail operation

Duplex Check Valve

• Maintenance– No schedule maintenance required between POH.

– During POH functional testing to be done.

– OVH after 03 yrs

Infrastructure for Mtc

• Open line/ POH– Tools

– Test eqpt

– Gauges

– Testing+Rejectable parameters

– failure during run

– Spares

– Warranty claims

• Parameter setting

Available Guidelines from RDSO

• CMI- 9802 (rev.1) May 2001 and CMI- 9802 (rev.2) Feb 2008 on Maintenance Instructions on Air Suspension for DC, Ac & AC-DC EMU/HHP DMU Coaches.

• CMI- RDSO/2009/CG/CMI-01 Sep.2009 on Maintenance Instructions on Air Suspension for Mainline Rajdhani Coaches with ICF Bogie

• C-K509 (rev.0) Aug 2005, C-K509 (rev.1) Jan 2008 and C-K509 (rev.2) Sep 2008 on Schedule of Technical Requirements of Air Spring Assembly for Mainline/Rajdhani Coaches for ICF Type Bogie.

• CK-407 Oct 2004 on Schedule of Technical Requirements of air spring control equipments.

Operating Instruction

• Maintain 7 bar pressure in compressor.

• In case of heavy leakage of air from air spring system,

– isolate the affected bogie and observe speed restriction

• at 50 kmph for DC, AC &AC-DC EMU/HHP DMU COACHES (CMI-9802-rev.2) and

• at 60 kmph for Mainline Rajdhani Coaches with ICF Bogie (CMI- RDSO/2009/CG/CMI-01) up to the terminal point for maintenance.

Dismantling of AS from LS Beam & Bogie Bolster

• Remove All Body, Bogie connections.

• Remove duplex check valve from bolster.

• Remove lateral & vertical shock absorber.

• Remove equalizing rod connection from both ends of lower spring beam if provided.

• Remove connection of levelling valve & installation lever.

• Remove all 6 or 4 No. Bolts and nut with the help of M12 or M20 Allen key and M12 or M20 spanner from bottom plate of air spring & lower spring beam

• Lift bolster up to bogie frame to clear the spigot of air spring.

• Slide air spring from lower spring seat.

Measurement and readings for hybrid coaches

Inspection & Maintenance

• Air spring– Inspect for any water collection in rubber

bellow of air spring

– Inspect the air spring for any damage or leakage.

– Inspect air spring seat and top plates for corrosion, if corrosion noticed is paint with primer & black paint

• LS beam– Inspect it’s all welding joints and repair if

required.

– Inspect air spring fixing holes of it for elongation, if elongated, build them to dia.13 mm or dia. 22 mm.

– Inspect the corrosion on it’s top surface, remove the corrosion, then paint with primer and black paint.

• Pipe line– Piping may be checked for any

leakage/damage by soap test and repair if required.

Maintenance Instructions

• Tightened the lock nut of installation lever after adjustment spring height/clearances.

• Provide a safety plate for leveling valve to avoid stone hitting etc.

• Ensure that all the fasteners are properly tightened.

• Check the leakage of all air joints and rectify if required.

• Ensure that installation lever is in position and tightened properly.

• Please ensure that Air spring height after inflating is 255+0/-5mm.

• Do not hinder with leveling valve and installation lever.

• Check visually the crack, deformation, aging of rubber parts.

• Check the leakage of joint between spring spigot and bolster. Change the o-rings on spigot if leakage is observed.

Leakage Testing

• Connect hosepipes on under frame piping with levelling valves.

• Connect pressure gauges to 150-litre reservoir.

• Provide packing in the gap between bolster & bogie frame.

• Connect the 150-litre reservoir to the source of pressure.

• Allow air in air springs to 9.0 kgf/cm2 by adjusting the horizontal lever of the levelling valve and keep it in the same position.

• Close the isolating cock of 150-litre reservoir.

• Test all pipe joints for leakages.

• Check the pressure gauge readings after one hour. The pressure drop should be within 1% of the test pressure 9.0 kgf/cm2•

• Release the air completely by dropping the horizontal lever.

• Remove the packing.

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