ABSTRACTIt is a live project which involves the design of Test stand for sub assemblies of distributor valves; relay valve is a recent attached of distributor valve. The objective of project is design and fabrication of sub assemblies of distributor valve which helps in rectifying, troubleshooting and periodic overhauling .This makes aware and helps to explain one of the best sophisticated, reliable, efficient braking system Fast expanding industrialization of the country needs fast movements of higher safety of men & material. Hence, the relay valve is introduced for distributor valve in Air brake system. previously trains used Vacuum Braking system but right now there are working Air braking system, as it has exceptional advantages over Air brake system Now Air Brakes had under gone many changes it has revolutionized speed reducing braking system with better reliable safety and in exhaustibility HISTORY OF RAIL TRANSPORT IN INDIA Q. When did the first train run in India? The customary answer to this question is 3:35pm on April 16th, 1853, when a train with 14 railway carriages and 400 guests left Bombay's Bori Bunder for Thane, with a 21-gun salute. It was hauled by three locomotives: Sindh, Sultan, and Sahib. The journey took an hour and fifteen minutes. That, however, was just the first commercial passenger service in India. In fact, a steam loco, Thomason, had been used for hauling construction material in Roorkee for the Solani viaduct in 1851 (it began working there on 22nd December 1851, to be exact). The Solani viaduct construction was a part of the Ganges Canal project, started in 1845. The viaduct had 15 arches and spanned the 4km-wide Solani valley (about 145km north-east of New Delhi). Earth for the approach embankments was transported along light rail lines about 5 to 10 km long from Piran Kaliyar to Roorkee. Standard gauge wagons were used, built from parts brought over from England, and hauled by men and later horses. In late 1851, the locomotive Thomason (named for the engineer on the project) was assembled on the spot from parts transported from Calcutta. It hauled two wagons at a time, at a speed of about 6km/h. It did not last very long, and after about 9 months India's first steam locomotive died a spectacular death with a boiler explosion, reportedly to the delight of the construction workers who had viewed it more as a hindrance than help. Hughes' book states that this was a six-wheeled tank engine, probably a 2-2-2WT built by E. B. Wilson, and of standard gauge. Some details of the wagons and the use of the locomotive are in Sir Proby T Cautley's "Report on the Ganges Canal Works" (3 volumes, 1860). "[The railway is] a triumph, to which, in comparison, all our victories in the East seem tame and commonplace. The opening of the Great Indian Peninsular Railway will be remembered by the natives of India when the battlefields of Plassey, Assaye, Meanee, and Goojerat have become landmarks of history." (The Overland Telegraph and Courier, April 1853)The second locomotive to arrive in India was Falkland (named for a governor of Bombay), used by the contractors of the GIPR for shunting operations on the first line out of Bombay that was being built. It began work on February 23, 1852. Hughes' book suggests that this was also built by E. B. Wilson, and was probably a four-wheeled tank engine (0-4-0T?) with dummy crankshaft. It later became GIPR loco #9. A third locomotive, Vulcan, is said to have been used by the GIPR for material hauling and shunting duties in 1852 as well. There were also eight more locos from Vulcan Foundry imported by GIPR in 1852 and 1853. On November 18, 1852, a locomotive hauled some coaches on a trial run from Bori Bunder to Thana. This probably counts as the first "real" train to run in India. Q. What was the Guarantee System? What were Guaranteed Railways? In the 1840s, when the first proposals for railways in India were being debated in Great Britain, there was intense lobbying in support of these proposals by banks, traders, shipping companies, and others who had a strong interest in seeing railways be formed in India. These supporters prevailed upon the British Parliament to create the Guarantee System, whereby any company that constructed railways in India was guaranteed a certain rate of interest on its capital investment. This guarantee was honoured by the East India Company which then controlled large parts of India. The railways that were formed with such agreements governing them were called guaranteed railways. Typically, the guarantee was for a return of 5% annually, and the right for the railway company to pull out of the venture and get compensation from the government at any time. Chronology of railways in India, Part 2 (1832 - 1865)Note: This chronology is intended as a general overview for non-specialists to give them a feel for some of the interesting and complex events that shaped the development of railways in India. Many line openings are mentioned to give an idea of the geographic spread of railway services. Dates in most cases are those for when the completed lines were open to traffic; usually sections of the line may have been opened years earlier, and might even have supported revenue traffic in parts. Dates are often somewhat uncertain because of varying reports in different sources, or lack of documentation, hence in many cases they may be off by a couple of years. Anyone seeking reliable and specific information and more detail is strongly urged to consult the reference works listed in the guide to historical research and the section on books about IR history A plan for a rail system in India was first put forward in 1832, but no further steps were taken for more than a decade. In 1844, the Governor-General of India lord Hardinge allowed private entrepreneurs to setup a rail system in India. Two new railway companies were created and the East India Company was asked to assist them. Interest from investors in the UK led to the rapid creation of a rail system over the next few years. The first train in India became operational on 22-12-1851, and was used for the hauling of construction material in Roorkee. A year and a half later, on 16-04-1853, the first passenger train service was inaugurated between Boribunder, Bombay and thane. Covering a distance of 34km (21 miles), it formally heralded the birth of railways in India. The British government encouraged new railway companies backed by private investors under a scheme that would guarantee an annual return of five percent during the initial years of operation. Once established, the company would be transferred to the government, with the original company retaining operational control. The route mileage of this network was about 14,500 km (9,000 miles) by 1880, mostly radiating inward from the three major port cities of Bombay, Madras and Calcutta. By 1895, India had started building its own locomotives, and in 1896 sent engineers and locomotives to help build the Uganda Railway. Soon various independent kingdoms built their own rail systems and the network spread to the regions that became the modern-day states of Assam, Rajasthan and Andhra Pradesh. A Railway board was constituted in 1901, but decision-making power was retained by the viceroy Lord Curzon. The Railway Board operated under aegis of the Department of commerce and Industry and had three members: a government railway official serving as chairman, a railway manager from England and an agent of one of the company railways. For the first time in its history, the Railway began to make a tidy profit. In 1907, almost all the rail companies were taken over by the government. The following year, the first electric locomotive appeared. With the arrival of the First World War, the railways were used to meet the needs of the British outside India. By the end of the First World War, the railways had suffered immensely and were in a poor state. The government took over the management of the Railways and removed the link between the financing of the Railways and other governmental revenues in 1920, a practice that continues to date with a separate railway budget. The Second World War severely crippled the railways as trains were diverted to the Middle East, and the railway workshops were converted into munitions workshops. At the time of independence in 1947, a large portion of the railways went to the then newly formed Pakistan. A total of forty-two separate railway systems, including thirtytwo lines owned by the former Indian princely states, were amalgamated as a single unit, which was christened as the Indian Railways. The existing rail networks were abandoned in favor of zones in 1951 and a total of six zones came into being in 1952. As the economy of India improved, almost all railway production units were indigenized. By 1985, steam locomotives were phased out in favor of diesel and electric locomotives. The entire railway reservation system was streamlined with computerization in 1995. HISTORY OF SOUTH CENTRAL RAILWAY CARRIAGE REPAIR WORKSHOP LALLAGUDA, SECUNDERABAD – 500 017 1. INTRODUCTION: South Central Railway, Carriage Repair Workshop, Lallaguda, Secunderabad, a premier repair workshop of Indian Railways was established on 30th September 1893. This workshop was under the argis of “THE NIZAM GUARANTEED STATE RAILWAYS” for undertaking periodic overhauling and repairs to BE and MG steam locomotives, coaches and wagons. Subsequently it was brought under the preview of “NIZAM STATE RAILWAYS.” Consequently upon the re-organization of Railways in 1951, this workshop became a integral part of Central Railways, subsequently South Central Railway was formed on 2nd October 1966 it became a major workshop for the zone. It continued to composite workshop for MG and BG rolling stock till 1969 when a repair to MG rolling stock was off loaded to Hubli workshop. With the tapering of Locos and bifurcation of wagons under wagon repair workshop at Guntapalli. Carriage workshop was exclusively meant for undertaking POH of carriages. This workshop occupies an area of 13.97 hectares with 4.25 hectares under cover. It is equipped and supported with full facilities within its premises. Carriage Repair Workshop of Lallaguda is one of the few integrated workshops in Indian Railways. In the past decades the workshop carried out periodically overhauling of the BG main line coaches including A/C coaches and backup manufacturing activities like Brake blocks, repairs of springs, maintenance of BD steam cranes. Prime activities of this workshop is periodical overhauling of BG and A/C coaches and corrosion repairs to the coaches with allied activities of manufacturing of carriage components like brake gear items, equalizing stays etc, formation of rakes for express trains, conversion of GS coaches. The other activities carried out in this workshops are 1) Laboratory headed by CMT, 2) Basic Training Center for imparting technical education and implementation of Apprentice Act 1961, and 3) Computer center under supervision of Dy.CME / Sr. EDPM in order to modernize the working system had been a boon. ……………………………………………………………………………………….. South central Railway was formed on 2nd October, 1966 as the 9th zone of the Indian Railways. In its thirty-eight years of committed service and bath breaking progress, south central Railway has grown to a modern system of mass transportation fulfilling the aspirations of the passengers/customers and carved a niche for itself in Indian Railways system. Strategically positioned in the southern peninsula this dynamic organization with its headquarters at secunderabad serves the economically vibrant state of Andhra Pradesh, part of Maharashtra, Madhya Pradesh and Tamil Naidu. From the days of steam hauled locomotives and wooden plank seats, south central Railway has a long way modernizing its system with the state of art high powered Diesel and Electric locomotives, high speed telescopic passenger coaches, and higher axle load wagons, higher capacity track in all important routes, multiple aspect color light signaling with solid state inter locking, micro wave and digital communication system etc. Over the years, south central railway has attained sufficient transportation output with adequate infrastructure development and technological upgrading to serve the regions in its jurisdiction. Safe operation of trains, expansion of network, modern passenger amenities, punctuality of trains, courteous service and cleanliness in stations and trains remain always the thrust areas of this railway. Being a service-oriented organization, south central railway provided computerized passenger reservation system at 85 stations/locations covering 96% of the berths available. In the arena of information dissemination to the rail customers, it has provided inter-action voice response system (IVRS) for reservation and train enquiry, national information on movement of trains, passenger operated enquiry terminals (POET) with information on availability of accommodation and confirmation and close circuit television (CCTV) for real time reservation availability. Status at all-important stations in its systems. For mass movement of freight, S.C.Railway has introduces high horse powered Diesel and Electric locomotives and high speed, high Axle load Box-N-Wagons. Today, south central railway plays a pivotal role as a catalyst for agricultural and industrial development in the southern peninsula apart from fostering the growth of trade and commerce including import/export through ports by connecting sea ports with their hinder land and inland container deports. Its reliable and comfortable passenger services for long and short distance travel by way introducing many super fast and inter city trains helps transform the society by catering to their personal, business, educational and tourism purposes. BRAKE: Any propelled or self propelled vehicle requires provision of effective braking system for retarding its speed or to bring the vehicle to stationary position as when requires. Higher the speed higher is the braking force. SALIENT FEATURES FOR BRAKE OPERATION Simplicity and convenience in manipulation. Integrity of the system. Reliability of the apparatus. Promptness in response to driver’s action. Absence of shocks. Simultaneous operation. Constancy in rates of braking. High rates of braking Graduated application. Unlimited applications. Compensation for loading. Constancy in all weathers. Absence of skidding. Immunity from track. There are three types of Brakes have been provided. 1. 2. 3. Hand Brake System. Automatic Vacuum Brake System. Air Brake System. HAND BRAKE: These brakes are provided in all Goods Stock, Guard Vans and Inspection Carriage. It can be used during shunting. PRINCIPLE OF VACUUM BRAKE: Vacuum derives its braking power from atmospheric pressure, which acts against the bottom of the piston when the brakes are applied. In this system, pressure differential is maintained between atmospheric pressure and that of vacuum. VACUUM BRAKE COMPONENTS: The vacuum cylinder suspended by trunnions from the underframe. Brake shaft. Rigging consisting mainly of Pull rods and Levers. Train Pipe and Pipe connects. Hand Brake (Lever or Screw type). VACUUM CYLINDER Position on the Underframe: Vacuum Cylinder is fitted on the under frame in vertical position in BG and MG stocks but in horizontal position NG stocks due to paucity of space between under frame and rail level. Sizes (Internal diameter basis) For BG Stocks: 24” 21” 18” For Heavier and high speed vehicles. For Medium weight vehicles. For Light weight vehicles. For MG & NG Stocks: 18” 15” For Heavier vehicles. For Light weight vehicles. TYPES OF VACUUM BRAKE: 1) 2) E – TYPE: In this type of vacuum cylinder, one dome shaped vacuum chamber is provided to increase the volume of the upper chamber. F – TYPE: In this type of Vacuum Cylinder, an auxiliary chamber is provided which is suspended to the under frame and connected with the top of the piston through a double branch release valve. AIR BRAKE SYSTEM For application of brakes in railway coaches and wagons with vacuum brake system we first withdraw air from the train system(create vacuum) and then allow the atmospheric air to reach below the piston in vacuum cylinder lifting the piston upwards which in turn apply brakes.But in air brake system it is the reverse case.In air brake system we first charge the train system with compressed air to certain predetermined level of air pressure through two pipes named feed pipes and brake pipes.The feed and brake pipes are charged to a pressure of 6.0 and 5.0 kg/cm^2 respectively.When brakes are to be applied the air pressure in brake pipe is reduced by the driver which actuates the distributor valve fitted under every wagon or coach on the train .The distributor valve supplies the compressed air from auxiliary reservoir to one side of the piston in the brake cylinder pushing out the piston rod and applying the brakes.The guard and the passengers can also apply the brakes in case of an emergency .During train partings and accidents brakes also apply automatically and with higher force than that of vacuum brakes.When the air pressure in brake pipe is restored to the normal pressure,the brakes are released. The brakes can also be manually released after the engine has been detached.After application of brakes in air brake system the brakes remain in on position for hours together. Only those engines which are fitted with the air brake system can only work such trains.Such wagons/coaches can also not be worked with other trains with vacuum brake system TWIN PIPE SYSTEM:-As already stated above each and every brake system has two air pipes from one end to the other end lengthwise. One pipe is used to continuosly charge/feed the compressed air to the auxiliary reservoir and is called as Feed pipe.The second pipe is used for application and releasing of brakes and is termed as Brake pipe.As such this system is called as Twin pipe system. This system has the following merits:Feed pipe charges the Auxiliary reservoir continuosly and maintains the predetermined air pressure in A.R(Auxiliary reservoir).On application of brakes the A.R’S compressed air is fed to the brake cylinder and there is a certain fall in air pressure in A.R due to the same.But the feed pipe immediately/simultaneously charges the A.R and maintains the desired air pressure in A.R.Any number of brake applications releasing may be done by the driver in quick succession, the air pressure in A.R will remain the same i.e; there will be no decrease in the air pressure of A.R. This feature is not possible in case feed pipe is removed/isolated from the Air brake system,because the brake pipe will have to shoulder the burden of feed pipe in addition to his own job.In such an event the charging of A.R will take more time to be ready for subsequent brake applications.Resultantly the application of brakes in quick succession is not possible. In case due to any reason one pipe of a coach or any wagon gets damaged or goes defective,it can be bypassed in twin pipe system and the detachment of the coach or wagon would not be essential as in the case of single pipe system,But in this case the train will be worked as single pipe system. SINGLE PIPE SYSTEM:-In this system there is provision of only one air pipe from one end of a wagon/coach to the other end instead of two pipes.This pipe is called as brake pipe.This brake pipe singularly charges the auxiliary reservoir and also applies and releases the brakes.In this system the driver feels very easy in maintaining/charging the brake pipe only but this is not so advantageous to that of Twin pipe system.In this system the auxiliary reservoir is not charged while the A.R supplies air to brake cylinder.As such brakes in quick succession cannot be applied and released.In case of any damage or defect in the air brake system of any coach/wagon,there is no alternative than to detach such coach/wagon from train enroute.In this system after emergency application of brakes the driver shall have to wait for some time to fully release the train before restarting other wise some danger to the train has to be faced. Therefore,the administration has adopted Twin pipe air brake system on the railways.The train examination staff must ensure that all trains examined by them are invariably having Twin pipe air brake system .In case a train terminates at their station with single pipe system they must thoroughly check and investigate the reasons for single pipe system and ensure necessary repairs to put the defective coach/wagon back to Twin pipe system. TYPES OF AIR BRAKES There are two types of air brakes which are present, they are, 1.Direct release system 2.Graduated release system Direct release system:- In this system when after application of brakes,the brakes are released,the air of the brake cylinder does not quickly go to the atmosphere through the distributor valve .Instead it goes slowly.The Distributor valve is not provided with such a feauture which may permit the air of brake cylinder to escape quickly and release the piston quickly .Second or subsequent application of brake is not possible until and unless the brake cylinder air is completely exhausted .It is not possible for the distributor valve to make the releasing movement of piston to abruptly change to applying position .As such the application and release of brakes in quick succession cannot be achieved at all.So this system is termed as Direct release system. Graduated release system:-In this system application and release of brakes in quick succession is feasible in any number of times .In this system the movement of piston from application to release and vice versa can be changed with decrease and increase of air pressure in B.P.In this case there is no need for completely discharging the air pressure of brake cylinder.The distributor valve fitted in this type ,has the special feature which actuates the brake cylinder piston with the decrease and increase in B.P ,pressure to the tune of 0.5 kg/cm^2 or above. At the time of speed restrictions or while negotiating down gradients it has become very easy to control the speed of the train to the will of driver.It is due to this reason that this system is called Graduated release system.. From the above ,one can easily understand that the type of air brake system in use on our railway system is Twin pipe graduated release air brake system .But we call it only air brake system in short which has the same meaning and nothing else as in the case of vacuum where partial vacuum is used but termed as vacuum only. PRINCIPLE OF OPERATION OF TWIN PIPE GRADUATED RELEASE AIR BRAKE SYSTEM: a. . . . . b. Charging the brake system Brake pipe throughout the length of train is charged with compressed air at 5 Kg/cm2 Feed pipe throughout the length of train is charged with compressed air at 6 Kg/cm2 Control reservoir is charged to 5 Kg/cm2 Auxiliary reservoir is charged to 5 Kg/cm2 Brake application stage . For brake application the brake pipe pressure is dropped by venting air from the driver’s brake vale. Subsequently the following action take place. . The control reservoir is disconnected from the brake pipe. . The distributor valve connects the auxiliary reservoir to the brake piston is pushed outwards for application of brakes. . The auxiliary reservoir is however continuously charged from feed pipe at 6 Kg/cm2 Description Minimum Brake Application Service Brake Application Full Service Brake Application Reduction in B. P. Pressure 0.5 to 0.8 Kg/cm2 1.0 to 1.0 Kg/cm2 Brake pipe is fully exhausted and its pressure reduces to almost zero. c. Brake release stage . Brakes are released by recharging brake pipes to 5 Kg/cm2 pressure through the driver’s brake valve. . The distributor valve isolates the brake cylinder from the auxiliary reservoirs. . The brake cylinder pressure is vented to atmosphere through DV and the Brake cylinder piston moves inwards. Coaches fitted with twin pipe graduated release air brake system with locomotive in the leading forms a complete rake.Locomotive is the source for supplying compressed air to the trailing coaches in the rake.The brake pipe and feed pipe run parallel to eachother throughout the length of the coach.The brake pipe and feed pipe of one coach are connected to the brake and feed pipe of adjacent coaches through cut off angle cocks and hose coupling. The air compresser of the locomotive stores the air in its main reservoir at a pressure of 8-10 kg/cm^2 and it is supplied to the system charging the feed pipes and brake pipes commonly called as FP and BP at a pressure of 6kg/cm^2 and 5kg/cm^2 respectively.Auxiliary reservoir is charged by the feed pipe through the check valve and isolating cock. The auxiliary reservoir is also charged by the brake pipe through distributor valve in case the feed pipe is unable to charge, or has been eliminated. For continuity of air pressure through out the rake ,the cut off angle cocks of the brake and the feed pipe and isolating cocks should be kept open. The cut off angle cocks on the last coach of the rake and front cut off angle cocks of the locomotive should be kept closed. Reduction of air pressure in the brake pipe whether intentionally or accidental actuates the distributor valve which causes rise of pressure in the brake cylinder and the brake apply .The magnitude of braking force increases in proportion to the reduction of air pressure in the brake pipe. Maximum braking force is attained when the brake pipe pressure is lowered and is in the range of 3.4 to 3.6kg/cm^2.In case of emergency(or accidents)the air pressure in brake pipe is reduced below from 3.4kg/cm^2 to hasten the brake application at a faster rate reducing the emergency braking distances. During application of brakes the air from auxiliary reservoir flows to the brake cylinder and the loss of air in auxiliary reservoir is made up by feed pipe continuously. The thrust of brake cylinder piston is transmitted through brake riggings magnifying the same through leverage to the brake blocks thereby producing braking force. The distributor valve is so sensitive that when air pressure is lowered or raised in the brake pipe it causes the brake application and release respectively. With the rise in air pressure it releases the brake cylinder by venting its air to the atmosphere and with the fall in the air pressure it applies brakes. Distributor valve which is fitted on the branch line of the brake pipe, controls all the activities related to the charging, application and release of the brake. (1)CHARGING :-Brake pipe is charged with air pressure at 5 kg/cm^2 through out the length of the rake and fills air in the distributor valve and control reservoir through dirt collectors. Feed pipe is charged with 6 kg/cm^2 through out the length of the rake and fills air in auxiliary reservoir through dirt collector and check valve with choke(Auxiliary reservoir is also charged by the brake pipe through the distribution valve). (2)APPLICATION :-In twin pipe graduated release system the driver of the train can apply brakes either in steps for graduated application or in one stroke for emergency application .This action causes reduction in brake pipe pressure due to its venting to atmosphere. The reduction in brake pipe pressure results in differential pressure building up across the diaphragms of the distributor valve .As a result the distributor valve connects the auxiliary reservoir to the brake cylinder causing the brake cylinder piston to come out .The piston movement causes brake application on individual coaches through the brake rigging arrangement. (3)RELEASE :-For releasing the train brakes the driver has to replenish the brake pipe pressure reduced during brake application by charging the system back to 5 kg/cm^2.The increased pressure is sensed by the distribution valve which disconnects the brake cylinder from the auxiliary reservoir and connects the brake cylinder to atmosphere through the distributor valve.The brake cylinder pressure is vented to atmosphere and brakes are released. To ensure service reliability of the air brake system of the coaches preventive periodic maintenance is carried out.The following maintenance schedules are carried out on the coaches. Schedule-A (Monthly examination) Schedule -B(Tri-monthly examination) Schedule-C(Half yearly examination) To ensure that the air brake system of the different coaches of a rake work in conjunction reliable round trip examination is carried out.For service reliability of the coaches ,the coaches of a rake are subjected to a periodic overhaul once in twelve months.Certain activities like inspection and testing of the air brake equipment of the coaches are carried out during POH.The air brake equipment of the coaches is to be completely dismantled and overhaul once in five years or on completion of 8 lakh kilometers which ever is earlier or when there is some specific trouble .When a coach comes for overhauling it is necessary to check whether the air brake equipment requires complete dismantling and over hauling.However the slack adjuster is to be over hauled every POH. AIR BRAKE SUB-ASSEMBLIES The various Air Brake sub-assemblies and components are: i) Common pipe bracket. ii) Intermediate piece. iii) Brake pipe and feed pipe. iv) Brake pipe coupling. v) Cut-off angle cock. vi) Brake cylinder. vii) Dirt collector. viii) Auxiliary reservoir. ix) Slack adjuster. x) Distributor valve. xi) Isolating cock. xii) PEASD. xiii) PEAV. xiv) Check valve. COMMON PIPE BRACKET Common pipe bracket is mounted on the coach under frame and is suitable for use with all type of distributor valves presently in use on main line coaches. INTERMEDIATE PIECE (SANDWICH PIECE) An intermediate piece is mounted on the common pipe bracket to fit the distributor valve on the common pipe bracket. The intermediate piece serves the purpose of blanking all the other ports on the common pipe bracket other than required for a particular make of distributor valve. Each type of distributor valve is mounted on the common pipe bracket with its own intermediate piece. BRAKE PIPE AND FEED PIPE Brake pipe and feed pipe of 25 mm bore and branch pipes of 20 mm bore have been provided. BRAKE PIPE COUPLING To maintain continuity through out the length of train, the brake pipe (BP) and feed pipe (FP) are fitted with flexible hoses. Each hose is provided with palm end coupling heads are painted with green colour for B.P and white colour for F.P. also raised letters ‘BP’ and ‘FP’ are embossed on coupling heads representing Brake Pipe and Feed Pipe respectively. Hose couplings must be checked for leakage of air as per the test procedure given below CUT OFF ANGLE COCK One cut off angle cock has been provided on either end of brake pipe and feed pipe that is to say on every coach on wagon a complement of 4 angle cocks are provided. The angle cocks used on feed pipes are painted white and those for brake pipes are given coating of paint green.The angle cocks are fitted with Teflon tape or paint white lead on the brake pipes and feed pipes and made air tight joints by tightening their rear adaptors fully.The top of the cock having handle is invariably kept facing upwards.The angle cocks are secured with under frame member with strong safety loop.So ,that the angle cock may not move to and fro and right or left in dynamic conditions.Angle cock has one front adaptor in which the nipple of the air hose coupling is screwed in with paint white lead or Teflon tape and made firm and air tight joint.The diameter of the rear adaptor of angle cock corresponds to the external diameter; of air pipes and the front adaptor’s diameter; matches with that of air hose nipple.Since there is difference in diameter;of air pipes used on wagons and coaches ,as such the angle cocks are not inter-changeable. The advantage of provision of cut off angle cocks on the brake and feed pipes is that after charging of air pressure in the air brake system ,if any coach or wagon has to be detached from a train formation, discharging of air pressure from whole train is not necessitated.The angle cocks of affected wagon and adjacent wagons or coaches are closed and the wagon/coach can be detached without any loss of air pressure and after re-formation of load and coupling up of air hoses, the train can be started immediately and there will be saving of time for recharging and building of pressure to desired levels as in the case of vacuum brake system,as the air pressure in rest of the wagon/coaches remains unaltered. BRAKE CYLINDER On every coach fitted with air brake system two brake cylinders are provided for actuating the brake rigging for the application of release of brakes. During application of brakes the brake cylinder develops mechanical brake power by outward movement of its piston assembly after receiving air pressure from Auxiliary reservoir through the distributor valve. This is transmitted to the brake shoes through a combination of leaves. During release action of brakes the compression spring provided of brakes the compression spring provided in the brake cylinder brings back the rigging to its original position. The cylinder body is made out of sheet metal or cast iron and carries the mounting bracket, air inlet connection, ribs and flange. DIRT COLLECTOR Two three way dirt collector are provided one each coach. One between brake pipe and DV and other in between feed pipe & auxiliary reservoir. Dirt collector prevents the entry of the dust and scale by centrifugal action followed by filtration arrangement in the distributor valve & auxiliary reservoir and other equipment in the system AUXILIARY RESERVOIR SALIENT FEATURES The auxiliary reservoir is a cylindrical vessel made of sheet metal. On both the ends of the reservoir, flanges are provided for pipe connections. One end of the auxiliary reservoir is connected to the brake pipe through the distributor valve. Auxiliary reservoir is charged through through the feed pipe to a pressure of 6kg/sq cm. At the bottom of the auxiliary reservoir, a drain cock is provided for draining out the condensate moisture. The auxiliary reservoir should be overhauled in every POH. SLACK ADJUSTER SALIENT FEATURES Slack adjuster (also known as brake regulator) is a device provided in the brake rigging for automatic adjustment of clearance/slack between brake blocks and wheel. It is fitted into the brake rigging as a part of mechanical pull rod. The slack adjuster is double acting and rapid working i.e. it quickly adjusts too large or too small clearance to a predetermined value known as ‘A’ dimension. The slack adjuster maintains this ‘A’ dimension throughout its operation. The slack passenger coaches, it is composed of the following parts. . Adjuster spindle with screw thread of quick pitches (non self-locking). . Tractioin unit containing adjuster nut, adjuster unit containing leader nut and barrel etc. . Control rod with head. The out standing features of slack adjuster IRSA-450 are: Fully Automatic i.e. once initially set, no manual adjustment is further necessary at any time during its operation. Double-Acting i.e. the brake shoe clearance is adjusted to its correct value both ways, either when it has become too large (owing to wear of the brake shoes and wheels) or when it has become too small (e.g. owing to renewal of worn out brake blocks). Rapid working i.e. correct brake shoe clearance is automatically restored after one or two applications of the brake. Verification i.e. if resistance occurs early in the brake application, caused by heavy brake rigging, e.g. an ice coating on the brake shoes, etc., in such cases the slack adjuster does not pay out slack immediately, but indexes the amount of slack to be paid out. If the slack really is too small, the slack adjuster will pay out this indexed slack at the next brake application. Thus false payout will not occur. True Slack Adjuster i.e. the slack adjusters incorrect slack only, thus giving the brake its best possible pre-adjusted limit of piston strokes, ensuring a smooth and efficient braking force at all times. Shock Resistant i.e. train shocks will not cause false take-up or payout of slack. When brakes are released, the moving parts of the slack adjuster are securely locked. ISOLATING COCK One isolating cock ball type is provided near each brake cyulidner on the branch pipe line connecting brake cylinder and distributor valve. One isolating cock ball type is also provided on the branch pipe connecting brake pipe and passenger emergency valve. These isolating cocks are used to isolate the air passage in case the brake cylinder / passenger emergency valve becomes defective. One isolating cock is also provided between centrifugal dirt collector of FP and check valve. The same may be isolated in the case of malfunction of DV or any breakage / damage in the branch pipes of the feed pipe. TESTING 1. 2. 3. PASSENGER EMERGENCY ALARM SIGNAL DEVICE (PEASD) Two such valves are fitted at can rail level, on one end wall of the coach. The operating spindle of the passenger emergency alarm signal equipment is connected to the disc rod and alarm disc rod is in turn connected to the alarm chain. These equipment are connected to passenger emergency valve by a common pipe of 10 mm bore. The PEASD can be reset with the square key kept with guard / TXR of the train. On all new coaches the PEASD has fixed reset key. TESTING 1. Hold the PEASD suitably with a pulling handle attached to operating spindle. Connect air supply of 5 kg / cm2 to port A and port B dummied suitably. 2. With the lever assembly at the bottom position check for leakage at the exhaust port and body all over with soap suds. There should not be any leakage. 3. With air supply on operate the device by pulling down the handle and note heavy blow of air through the exhaust port. 4. Quickly rest the device by using the suitable spring key and rotating the lever assembly clock-wise and note the exhaust of air stops completely. PASSENGER EMERGENCY VALVE (PEAV) This equipment is fitted on the end wall. It is connected to the brake pipe through isolating cock and is also connected to the passenger alarm signal device. During the operation of the alarm chain from inside the compartment, the disc rod rotates and lifts the operating spindle of the passenger alarm signal device and in this process the air in the pipe between passenger alarm signal device and PEAV is depleted. The difference in the air pressure actuates the PEAV and the brake pipe pressure gets depleted to the atmosphere through PEAV exhaust having a choke of 4 mm dia. Depletion of brake pipe will initiate a brake application. PEAV also contains a micro – switch which is utilised to provide an audio – visual indication to the driver of the train. The driver also gets the indication of alarm chain operation through increase in the requirement of air in flow meter. TESTING 1. Connect one end of 110 cu. In. volume reservoir to the BP Control Air Port of the Relay Valve. The other end of the reservoir to a ½” drain cock via a pressure gauge. Also connect 5 kg / cm2 compressed air supply to BP inlet to the relay valve. Remove the choke from the exhaust passage of the valve. Handle “ OFF “ position – Check leakage at outlet port at air pressure 10 kg / cm2. There should not be any leakage. Close the outlet port using a blank plate and check leakage all over the body at air pressure 10 kg / cm2. There should not be any leakage. 2. With the ½” drain cock closed, open the 5 kg / cm2 air supply to the relay valve. Note that the pressure gauge of the reservoir quickly register 5 kg / cm 2 pressure and no leakage in the exhaust port. 3. Apply soap suds all over body. No leakage is permissible. 4. Open the ½” drain cock and note the reservoir pressure quickly drops to zero, and at the same time the relay valve starts exhausting the BP. 5. Close the drain cock and note as the reservoir pressure builds up and tends to equalise with the supply pressure, the relay stops exhausting. 6. At close of test and before installation of the relay valve on to the coach for back the choke on the exhaust passage. CHECK VALVE WITH CHOKE One such set is provided in the branch pipe connecting FP & AR. It ensures supply of compressed air from feed pipe to auxiliary reservoir and prevents its return flow, thus avoiding fall in air pressure below 5 kg/cm2 in the event of failure on air supply from feed pipe. A 3 mm dia choke is provided on the outlet port of the check valve to control the quantum of air flow from feed pipe, so that the auxiliary reservoirs on all the coaches of a train can be uniformly filled. TESTING: 1. 2. Connect air supply at 10 kg / cm2 to the inlet port air should flow freely through the outlet port. Block outlet port and permit air at 10 kg / cm2 through the inlet port. Check for leakage all over the body and joints by soap water. There should not be any leakage. Connect air supply at 2 kg / cm2 to the outlet port. There should be no air flow / leak through the inlet port. Repeat the test at air pressure 5 kg / cm2. 3. Working principle Air Brake System (Passenger Rake) The Brake pipe and feed pipe run parallel to each other through out the length of the coach. The brake pipe and the feed pipe of one coach are connected to the brake pipe and feed pipe of adjacent coaches. Through cut off angle cocks and hose-couplings Air compressor located in the locomotive supplies air pressure at 5 kg/cm2 to the brake pipe through the drivers’s brake value The air compressor also supplies air at 6 kg.cm2 through a series of values to the feed pipe For continuity of air pressure through out the rake , the cut-off angle cocks of the brake and the feed pipe and isolating cocks should be kept open. The cit-off angle cocks on the last coach of the rake and front cut-off angle cocks of the locomotive should be kept closed Working Principle Air Brake System (Passenger Rake) Distributor Value which is fitted on the branch line of the brake pipe Controls all the activities related to the charging , application and release of the brake 1. Charging : Brake pipe is charged with air pressure at 5 kg/cm2 through out the length of the rake and fills air in the distributor value and control reservoir through dirt collectors . Feed pipe is charged with 6 kg/cm2 through out the length of the rake and fills air in auxiliary reservoirs through dirt collectors and check value with choke (auxiliary reservoir is also charged by the brake pipe through the distributor value) 2. Application : In twin pipe graduated release system the driver of the train can apply brakes either in steps for graduated application or in one stroke for emergency application . This action caused reduction in brake pipe pressure due Working Principle Air Brake System(Passenger Rake) To its venting to atmosphere . The reduction in brake pipe pressure results in differential pressure building up across the disphragms of the distributor value As a result the dis tributor value connects the auxiliary reservoir to the brake Cylinders causing the brake cylinder piston to come out . The piston movement causes barke application on individual coaches through the barje rigging 3. Release : For releasing the train brakes the driver has to replenish the brake pipe pressure reducted during brake applicatons by charging the system back to 5 kg/cm2 . The increased pressure in sensed by the distributor value which disconnects the brakes cylinders from the auxiliary reservoir and connects the brake cylinder to atmosphere through the distributor value . The brake cylinder pressure is vented to atmosphere and brakes are released Function Air Brake System (Passenger Rake) Coaches fitted with twin pipe graduated release air brake system with locomotive in the leading forms a complete rake. Locomotive is the source for supplying compressed air to the trailing coaches in the rake The brake pipe of coaches is charged with compressed air through the drivers brake value and the fed-pipe of the coaches is charged through the main reservoir of the locomotive via additional relay value The brake pipe and the feed pipe of the coaches in the rake are connected to the subsequent coaches through hose couplings for compressed air to flow for operating the braje system are fitted in the under frame These equipments and their functions are discussed in details separately Passenger emergency alarm system is provided in the coaches for passengers initiation of train brakes in the event of emergency safety Maintenance Air Brake System (Passenger Rake) To ensure service reliability of the air brake system of the coaches preventive periodic maintenance on the coaches are carried out The following Maintenance schedule are carried out on the coaches Schedule –A (Monthly Examination) Schedule-B(Tri-Monthly Examination) Schedule-C (Half Yearly Examination) The above maintenance schedule being pertinent to maintenance of coaches are discussed in detail in the section of maintenance of Air Brake System ( Passenger Coaches ). To ensure that the air brake system of the different coaches of a rake work in conjunction reliably round trip examination is carried out Over Hauling Air Brake System (Passenger Rake ) To ensure service reliability of the coaches the coaches of a rake are subjected to a periodic overhaul once in twelve months . Certain activities like inspection and testing of the ar brake equipment of the coaches are carried out during POH The air brake equipment of the coaches is to be completely dismantled and overhaul once is five years or on completion of 8 lakh kilometers which ever is earlier or when there is some specific trouble When a coach comes for overhauling it is necessary to check whether the air brake equipment requires complete dismantling and overhauling of individual of the air brake system see the respective section of overhauling of the component Introduction Fast expanding industrialization of country needs fast movement of higher freight and passenger traffic coupled with safety of men and material.hence the railway administration took the challenge and introduced highly efficient and reliable AIR BRAKE SYSTEM over than vacuum brake system.Thus conventional vacuum brake system on these stock has been replaced which has several limitations as under:1.Brake fade. 2.Increased timings for release after application. 3.Limitations on train loads and lengths .Amount of vacuum in the rear portion is not maintained as desired 4.Higher maintenance costs 5.Speed.limitations 6.Lesser braking force generation by the piston 7.Difficult to create adequate amount of vacuum on Ghat sections 8.Upgrading of brake power before entry to ghat sections Whereas the AIR BRAKE SYSTEM has the following major advantages over the vacuum brake system:1.Speed of trains are increased 2.Axle load of wagon has been increased 3.Increased freight per train 4.Shorter braking distances 5.Compact and easy to maintain resulting in better utilization of rolling stock 6.Availability of optimum and uniform brake power enabling handling heavier trains, needing no augmentation before entering ghat section 7.Better reliability and safety 8.Higher pay load due to its being lighter in weight 9.Inexhaustibility AIR BRAKE SYSTEM For application of brakes in railway coaches and wagons with vacuum brake system we first withdraw air from the train system(create vacuum) and then allow the atmospheric air to reach below the piston in vacuum cylinder lifting the piston upwards which in turn apply brakes.But in air brake system it is the reverse case.In air brake system we first charge the train system with compressed air to certain predetermined level of air pressure through two pipes named feed pipes and brake pipes.The feed and brake pipes are charged to a pressure of 6.0 and 5.0 kg/cm^2 respectively.When brakes are to be applied the air pressure in brake pipe is reduced by the driver which actuates the distributor valve fitted under every wagon or coach on the train .The distributor valve supplies the compressed air from auxiliary reservoir to one side of the piston in the brake cylinder pushing out the piston rod and applying the brakes.The guard and the passengers can also apply the brakes in case of an emergency .During train partings and accidents brakes also apply automatically and with higher force than that of vacuum brakes.When the air pressure in brake pipe is restored to the normal pressure,the brakes are released. The brakes can also be manually released after the engine has been detached.After application of brakes in air brake system the brakes remain in on position for hours together. Only those engines which are fitted with the air brake system can only work such trains.Such wagons/coaches can also not be worked with other trains with vacuum brake system TWIN PIPE SYSTEM:-As already stated above each and every brake system has two air pipes from one end to the other end lengthwise.One pipe is used to continuosly charge/feed the compressed air to the auxiliary reservoir and is called as Feed pipe.The second pipe is used for application and releasing of brakes and is termed as Brake pipe.As such this system is called as Twin pipe system.This system has the following merits:Feed pipe charges the Auxiliary reservoir continuosly and maintains the predetermined air pressure in A.R(Auxiliary reservoir).On application of brakes the A.R’S compressed air is fed to the brake cylinder and there is a certain fall in air pressure in A.R due to the same.But the feed pipe immediately/simultaneously charges the A.R and maintains the desired air pressure in A.R.Any number of brake applications releasing may be done by the driver in quick succession, the air pressure in A.R will remain the same i.e; there will be no decrease in the air pressure of A.R. This feature is not possible in case feed pipe is removed/isolated from the Air brake system,because the brake pipe will have to shoulder the burden of feed pipe in addition to his own job.In such an event the charging of A.R will take more time to be ready for subsequent brake applications.Resultantly the application of brakes in quick succession is not possible. In case due to any reason one pipe of a coach or any wagon gets damaged or goes defective,it can be bypassed in twin pipe system and the detachment of the coach or wagon would not be essential as in the case of single pipe system,But in this case the train will be worked as single pipe system. SINGLE PIPE SYSTEM:-In this system there is provision of only one air pipe from one end of a wagon/coach to the other end instead of two pipes.This pipe is called as brake pipe.This brake pipe singularly charges the auxiliary reservoir and also applies and releases the brakes.In this system the driver feels very easy in maintaining/charging the brake pipe only but this is not so advantageous to that of Twin pipe system.In this system the auxiliary reservoir is not charged while the A.R supplies air to brake cylinder.As such brakes in quick succession cannot be applied and released.In case of any damage or defect in the air brake system of any coach/wagon,there is no alternative than to detach such coach/wagon from train enroute.In this system after emergency application of brakes the driver shall have to wait for some time to fully release the train before restarting other wise some danger to the train has to be faced. Therefore,the administration has adopted Twin pipe air brake system on the railways.The train examination staff must ensure that all trains examined by them are invariably having Twin pipe air brake system .In case a train terminates at their station with single pipe system they must thoroughly check and investigate the reasons for single pipe system and ensure necessary repairs to put the defective coach/wagon back to Twin pipe system. TYPES OF AIR BRAKES There are two types of air brakes which are present, they are, 1.Direct release system 2.Graduated release system Direct release system:- In this system when after application of brakes,the brakes are released,the air of the brake cylinder does not quickly go to the atmosphere through the distributor valve .Instead it goes slowly.The Distributor valve is not provided with such a feauture which may permit the air of brake cylinder to escape quickly and release the piston quickly .Second or subsequent application of brake is not possible until and unless the brake cylinder air is completely exhausted .It is not possible for the distributor valve to make the releasing movement of piston to abruptly change to applying position .As such the application and release of brakes in quick succession cannot be achieved at all.So this system is termed as Direct release system. Graduated release system:-In this system application and release of brakes in quick succession is feasible in any number of times .In this system the movement of piston from application to release and vice versa can be changed with decrease and increase of air pressure in B.P.In this case there is no need for completely discharging the air pressure of brake cylinder.The distributor valve fitted in this type ,has the special feature which actuates the brake cylinder piston with the decrease and increase in B.P ,pressure to the tune of 0.5 kg/cm^2 or above. At the time of speed restrictions or while negotiating down gradients it has become very easy to control the speed of the train to the will of driver.It is due to this reason that this system is called Graduated release system.. From the above ,one can easily understand that the type of air brake system in use on our railway system is Twin pipe graduated release air brake system .But we call it only air brake system in short which has the same meaning and nothing else as in the case of vacuum where partial vacuum is used but termed as vacuum only. AIR BRAKE SYSTEM INTRODUCTION: 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 legth of the train. The feed pipe is connected to the brake cylinder through the distributor valve. Brake application takes place by dropping the pressure in the brake pipe. PRINCIPLE OF OPERATION OF TWIN PIPE GRADUATED RELEASE AIR BRAKE SYSTEM: a. . . . . b. Charging the brake system Brake pipe throughout the length of train is charged with compressed air at 5 Kg/cm2 Feed pipe throughout the length of train is charged with compressed air at 6 Kg/cm2 Control reservoir is charged to 5 Kg/cm2 Auxiliary reservoir is charged to 5 Kg/cm2 Brake application stage . For brake application the brake pipe pressure is dropped by venting air from the driver’s brake vale. Subsequently the following action take place. . The control reservoir is disconnected from the brake pipe. . The distributor valve connects the auxiliary reservoir to the brake piston is pushed outwards for application of brakes. . The auxiliary reservoir is however continuously charged from feed pipe at 6 Kg/cm2 Description Reduction in B. P. Pressure Minimum Brake Application Service Brake Application Full Service Brake Application 0.5 to 0.8 Kg/cm2 1.0 to 1.0 Kg/cm2 Brake pipe is fully exhausted and its pressure reduces to almost zero. c. Brake release stage . Brakes are released by recharging brake pipes to 5 Kg/cm2 pressure through the driver’s brake valve. . The distributor valve isolates the brake cylinder from the auxiliary reservoirs. . The brake cylinder pressure is vented to atmosphere through DV and the Brake cylinder piston moves inwards. AIR BRAKE SUB-ASSEMBLIES The various Air Brake sub-assemblies and components are: xv) Common pipe bracket. xvi) Intermediate piece. xvii) Brake pipe and feed pipe. xviii) Brake pipe coupling. xix) Cut-off angle cock. xx) Brake cylinder. xxi) Dirt collector. xxii) Auxiliary reservoir. xxiii) Slack adjuster. xxiv) Distributor valve. xxv) Isolating cock. xxvi) PEASD. xxvii) PEAV. xxviii) Check valve. The brief details of the air brake components and it’s maintenance and test procedure is described below: COMMON PIPE BRAKET Common pipe bracket is mounted on the coach under frame and is suitable for use with all type of distributor valves presently in use on main line coaches. INTERMEDIATE PIECE (SANDWICH PIECE) An intermediate piece is mounted on the common pipe bracket to fit the distributor valve on the common pipe bracket. The intermediate piece serves the purpose of blanking all the other ports on the common pipe bracket other than required for a particular make of distributor valve. Each type of distributor valve is mounted on the common pipe bracket with its own intermediate piece. AIR BRAKE HOSES Brake Pipe and Feed Pipe Hoses To maintain continuity through out the length of train, the brake pipe (BP) and feed pipe (FP) are fitted with flexible hoses. Each hose is provided with palm end coupling heads are painted with green colour for B.P and white colour for F.P. also raised letters ‘BP’ and ‘FP’ are embossed on coupling heads representing Brake Pipe and Feed Pipe respectively. Hose couplings must be checked for leakage of air as per the test procedure given below CUT OFF ANGLE COCK Cut off angle cocks are provided both on brake pipe and feed pipe on either end of each coach to facilitate coupling and uncoupling of air hoses. Testing and Cut Off Angle Cock Tools and Equipment . . . . . . Test Bench Compressor to build pressure up to 10 kg/cm2. Single ended spanner as per IS 2027 a) Across face 17 (for M10 lock nut) 1No. b) Across face 13 (for M8 STUDS) 2No. Screw Driver –300mm, 1 No. 1 ¼ “ BSP dummy Plug with seal. Dummy plug for angle cock. BRAKE CYLINDER On every coach fitted with air brake system two brake cylinders are provided for actuating the brake rigging for the application of release of brakes. During application of brakes the brake cylinder develops mechanical brake power by outward movement of its piston assembly after receiving air pressure from Auxiliary reservoir through the distributor valve. This is transmitted to the brake shoes through a combination of leaves. During release action of brakes the compression spring provided of brakes the compression spring provided in the brake cylinder brings back the rigging to its original position. The cylinder body is made out of sheet metal or cast iron and carries the mounting bracket, air inlet connection, ribs and flange. Tools and Equipments Serial No. 1. 2. 3. 4. 5. 6. 7. Description Torque Wrench 0-3 Kg m range. Double End Spanner 24x27 mm across face (for M16). Double End Spanner across face 13x 14 (for M12). Socket Wrench 19 mm (for M12). Screw Driver 12” (300). Special fixture (Screw press/ Pucumatic). Gauge for examining bore of the cylinder. Inspection and Repairs of the Parts . Examine visually that the internal surface is free from scratches, rust. . Brake cylinder bore to be checked for ovality with gauge. . Check the characteristics of the return spring. . Piston trunk to be checked for wear and tear. . Pin, piston rod should be checked for wear. . Dome cover shall be checked for excessive wear and if worn build up with welding and thereafter re-bore to required size. . Gange, bush bore of the piston rod, replace it if worn. Testing of Brake Cylinder Body for Leakage Before assembly, put dummy plate on the dome side and subject the brake cylinder for hydraulic pressure of 10 Kg/cm2 for 5 minutes. No leakage is permitted. Testing of Brake Cylinder i) Brake Cylinder Test Bench Test bench consists of the following main parts a) 5 nos. of isolating cocks (1a, 1b,1c,1d,1e and 1f). b) Pressure reducing valves as below c) 2a –to be set on 10 Kg/cm2. d) 2b –to be set on 6 Kg/cm2. e) 2c –to be set on 0.8 Kg/cm2. f) 2d –to be set on 3.8 Kg/cm2. g) Pressure gauges. h) 6a –to measure supply pressure. i) 6b –to measure brake cylinder pressure. j) Pipe line filter –Item no 3. k) Brake cylinder pressure mounting base with fixture –Item no4. l) Air reservoir –Item no.5. AUXILIARY RESERVOIR SALIENT FEATURES The auxiliary reservoir is a cylindrical vessel made of sheet metal. On both the ends of the reservoir, flanges are provided for pipe connections. One end of the auxiliary reservoir is connected to the brake pipe through the distributor valve. Auxiliary reservoir is charged through through the feed pipe to a pressure of 6kg/sq cm. At the bottom of the auxiliary reservoir, a drain cock is provided for draining out the condensate moisture. The auxiliary reservoir should be overhauled in every POH. SLACK ADJUSTER SALIENT FEATURES Slack adjuster (also known as brake regulator) is a device provided in the brake rigging for automatic adjustment of clearance/slack between brake blocks and wheel. It is fitted into the brake rigging as a part of mechanical pull rod. The slack adjuster is double acting and rapid working i.e. it quickly adjusts too large or too small clearance to a predetermined value known as ‘A’ dimension. The slack adjuster maintains this ‘A’ dimension throughout its operation. The slack passenger coaches, it is composed of the following parts. . Adjuster spindle with screw thread of quick pitches (non self-locking). . Tractioin unit containing adjuster nut, adjuster unit containing leader nut and barrel etc. . Control rod with head. The out standing features of slack adjuster IRSA-450 are: Fully Automatic i.e. once initially set, no manual adjustment is further necessary at any time during its operation. Double-Acting i.e. the brake shoe clearance is adjusted to its correct value both ways, either when it has become too large (owing to wear of the brake shoes and wheels) or when it has become too small (e.g. owing to renewal of worn out brake blocks). Rapid working i.e. correct brake shoe clearance is automatically restored after one or two applications of the brake. Verification i.e. if resistance occurs early in the brake application, caused by heavy brake rigging, e.g. an ice coating on the brake shoes, etc., in such cases the slack adjuster does not pay out slack immediately, but indexes the amount of slack to be paid out. If the slack really is too small, the slack adjuster will pay out this indexed slack at the next brake application. Thus false payout will not occur. True Slack Adjuster i.e. the slack adjusters incorrect slack only, thus giving the brake its best possible pre-adjusted limit of piston strokes, ensuring a smooth and efficient braking force at all times. Shock Resistant i.e. train shocks will not cause false take-up or payout of slack. When brakes are released, the moving parts of the slack adjuster are securely locked. CARRIAGE REPAIR WORKSHOP LALLAGUDA, SECUNDERABAD – 500 017 1. INTRODUCTION: South Central Railway, Carriage Repair Workshop, Lallaguda, Secunderabad, a premier repair workshop of Indian Railways was established on 30th September 1893. This workshop was under the argis of “THE NIZAM GUARANTEED STATE RAILWAYS” for undertaking periodic overhauling and repairs to BE and MG steam locomotives, coaches and wagons. Subsequently it was brought under the preview of “NIZAM STATE RAILWAYS.” Consequently upon the re-organization of Railways in 1951, this workshop became a integral part of Central Railways, subsequently South Central Railway was formed on 2nd October 1966 it became a major workshop for the zone. It continued to composite workshop for MG and BG rolling stock till 1969 when a repair to MG rolling stock was off loaded to Hubli workshop. With the tapering of Locos and bifurcation of wagons under wagon repair workshop at Guntapalli. Carriage workshop was exclusively meant for undertaking POH of carriages. This workshop occupies an area of 13.97 hectares with 4.25 hectares under cover. It is equipped and supported with full facilities within its premises. Carriage Repair Workshop of Lallaguda is one of the few integrated workshops in Indian Railways. In the past decades the workshop carried out periodically overhauling of the BG main line coaches including A/C coaches and backup manufacturing activities like Brake blocks, repairs of springs, maintenance of BD steam cranes. Prime activities of this workshop is periodical overhauling of BG and A/C coaches and corrosion repairs to the coaches with allied activities of manufacturing of carriage components like brake gear items, equalizing stays etc, formation of rakes for express trains, conversion of GS coaches. The other activities carried out in this workshops are 1) Laboratory headed by CMT, 2) Basic Training Center for imparting technical education and implementation of Apprentice Act 1961, and 3) Computer center under supervision of Dy.CME / Sr. EDPM in order to modernize the working system had been a boon. DISTRIBUTOR VALVE Distributor valve is the most important functional component of the air brake system and is also sometimes referred to as the heart of the air brake system. The distributor valve senses drop and rise in brake pipe pressure for brake application and release respectively. It is connected to the brake pipe through branch pipe. Various other components connected to the distributor valve are auxiliary reservoir, brake cylinders and reservoir.control Function of Distributor Valve For application and release of brakes the brake pipe pressure has to be reduced and increased pipe pressure has to be reduced and increased respectively with the help of driver’s brake valve. During these operations the distributor valve mainly performs the following functions. (i) Charges the air brake system to regime pressure during normal running condition. (ii) Helps in graduated brake application, when preaaure in brake pipe is reduced in steps. (iii) Helps in graduated brake release, when pressure in brake pipe is increased I steps. (iv) Quickly propagates reduction of pressure I brake pipe throughout the length of the train by arranging additional air pressure reduction locally inside the distributor valve. (v) Limits maximum brake cylinder pressure for full service application/emergency application. (vi) Controls the time for brake application and brake release depending on service conditions. (vii) Facilitates complete discharge of air from the air brake system manually with the help of operating lever. (viii) Protects overcharging of control reservoir when the brake pipe pressure is quickly increased for releasing the brakes. Three designs of distributor valves are in use on coaches. These are: i) ii) iii) C3W type distributor valve. KE type distributor valve. P4AG type distributor valve. C3W DISTRIBUTOR VALVE The C3W Distributor Valve consists of. i. ii. Main body Quick service valve iii. iv. v. vi. vii. viii. ix. Main valve Limiting device Double release valve Auxiliary reservoir check vale Cut off valve Application chock Release chock Operation of C3W Distributor Valve For effective functioning of the air brake system, the distributor valve has to operate effectively during i) ii) iii) Charging stage Application stage and Release stage Charging Stage During charging stage the compressed air flows from the brake pipe and enters into the brake pipe chamber of the main valve, cut off valve and quick service valve. Due to this pressure the various valves get, activated and perform as under. Main Valve: Due to brake pipe pressure acting on top face of the large diaphragm, differential pressure acts on the main valve. As a result the hollow stem moves downwards there by connecting brake cylinder to atmosphere. In addition to this because of BP pressure at top of large diaphragm it presses ring and trigger. This action unlocks the CR release valve by raising upward the locking rod. Cut Off Valve: As brake pipe pressure enters into the cut off valve it flows through the solex jet and valve, (which is held open due to action of BP pressure on bottom side of the lower diaphragm) to the control reservoir. As the CR and BP pressure equalizes, diaphragm assembly come down and valve reach to lap position, the control reservoir pressure now also reaches to the upper portion of top diaphragm of quick service valve and the bottom portion of large diaphragm of main valve. Simultaneously, the auxiliary reservoir is charged with BP pressure reaching from cut off valve chamber – via auxiliary reservoir check valve. . EMERGENCY APPLICATION During emergency application the brake pipe pressure is reduced rapidly to 0 kg/cm2 by the driver’s brake valve. Because of this drop the position of the various valves will be as described below. Main valve: With drop in BP pressure to 0 kg/cm2 differential pressure acts across the large diaphragm. As a result the hollow stem is moved in upward direction and pushes the chock valve there by opening the passage for entry of auxiliary reservoir pressure at top portion of main valve. This pressure then gets a way to brake cylinder thus gets a way to brake cylinder through limiting device. The brake cylinder thus gets charged with the compressed air. This pressure is known as BC-pressure. Limiting Device: The auxiliary reservoir pressure which entered into the top position of main valve now enters the limiting device through the valve which is held open. From limiting device air pressure now enter the brake cylinder. When the BC pressure rises to 3.8 kg/cm2 the upwards force on the bottom of the guide and the valve at the bottom of the limiting device gets closed. Thus further entry of air into the brake cylinder stops. When the brake cylinder pressure reaches 3.8 kg/cm2 this pressure i.e. BC pressure act on . . . Top face of small diaphragm of main valve. Bottom face of upper diaphragm of cut off valve. Top (small chamber) of quick service valve. Now because of this BC pressure acting at main valve small diaphragm, the hollow stem is pulled down. As a result the check valve at top comes down to close stage and assume lap position with the hollow stem closing further entry of AR pressure. Cut off valve: In cut off valve the bottom face of the upper diaphragm is subjected to BC pressure because of which the guide is lifted. Also the upper portion of lower diaphragm is subjected to CR pressure, which pushes the total assembly downwards. This action closes the valve of cut off valve, there by isolating it from control reservoir pressure. Quick Service Valve: In quick service valve BC pressure acts at top of valve and control reservoir pressure act at top face of upper diaphragm. As a result the stem is pushed down. The valve at the bottom gets opened. Now as the BP pressure inside the DV is at 0 kg/cm2 the residue inside BP pressure from the bulb of quick service valve will flow back and vent to atmosphere with the BP line. GRADUATED APPLICATION During graduated brake application the brake pipe pressure is dropped in steps by driver’s brake valve. The movement of various valve assemblies is almost in the same direction, but their movement is comparatively less. In the main valve however after each application the hollow stem assumes the lap position with the check valve. In addition to this during graduated application the bottom valve of limiting device is held open to allow compressed air to enter into brake cylinder. When BC pressure reaches 3.8 kg/cm2 the bottom valve in the limiting device gets closed. Similarly at the time of full service application as the BC pressure reaches 3.8(+_) 0.1 kg/cm2 within specified time, the position of various valve assemblies will be the same as described above. iii) Release Stage When the brake pipe pressure is increased in steps for graduated release of the different valves is as described below: Main valve: At the top face of large diaphragm as the BP pressure increases, the hollow stem is moved downward leaving its lap position with check valve. The BC pressure thus finds a passage from top of hollow stem to exhaust to the atmosphere. This action reduces pressure on top of the upper diaphragm and the hollow stem again lifts up to lap portion. It close the hollow stem top portion. The same cycle is repeated when BP is increased during next stages. In this way graduated release effect is obtained. Cut off valve: As the BP pressure increases the position of cut valve remains similar as in graduated application i.e. the cut off valve will remain closed, isolating CR pressure from brake pipe pressure. Quick service valve: When the BP pressure is increased then as explained above for the main valve the BC pressure gets exhausted to atmosphere. This action gradually reduces the BC pressure. When BC pressure reduces the BC pressure. When BC pressure reduces to 0.8 kg/cm2 during brake release the force at the top of the quick service valve, becomes comparatively less than BP pressure present in Quick Service Valve. As a result the valve at top gets lifted thereby giving passage to blocked BP pressure to atmosphere. With the exhaust of BP pressure the Quick service valve of the distributor valve again ready for next brake application. Manual release: Double release valve provides for accelerated manual brake release, which is particularly useful during shunting operation. A short pull on the leaver of double release valve is all that is needed. This action opens the control reservoir release check valve, which is then held open by the locking rod. Venting of reservoir release check valve brings the main valve to release position and exhaust the brake cylinder pressure through the hollow stem. \ KE DISTRIBUTOR VALVE Operation of KE Distributor Valve For effective functioning of the air brake system the KEGisl distributor valve has to operate effectively during Charging stage Application stage and Release stage. (i) Charging Stage During charging this stage the compressed air flows from the driver’s brake valve into the brake pipe which charges the control reservoir, bottom cover chamber and auxiliary reservoir. In twin pipe air brake system the auxiliary reservoir is also charged through the feed pipe from the rear end. Charging of control reservoir During charging the compressed air flows from brake pipe, dirt collector, isolating valve and through choke to brake pipe chamber above the large piston and to the ‘A’ controller. Due to brake pipe pressure acting on top of the large piston, the three pressure valve is pushed down and port gets closed by the large diaphragm. Air also flows to the ‘A’ controller through chock. It passes through sensitivity port 2 and from there to the bottom cover chamber through port 2c. from the bottom cover chamber the air enters the control reservoir. When the BP pressure above the large diaphragm gets equal to control reservoir pressure (at bottom cover chamber) the large piston diaphragm gets lifted up and opens port 2b. Charging of Auxiliary Reservoir For charging the auxiliary reservoir air from BP passes from dirt collector to the ‘R’ charger via the isolating valve. Air entering the ‘R’ charger passes through the intermediate piece and opens the sealing flap. There from air enters the auxiliary reservoir and charges it to 5 kg/cm2. Simultaneously the auxiliary reservoir is charged by the feed pipe through dirt collector, isolating cock and check valve with chock to 6 kg/cm2 from the rear end. Application Stage : The application of brakes can either be emergency ,full service or graduated Emergency application When the brake pipe pressure is reduced from 5kg/cm2 to zero the passage from auxiliary reservoir to the brake pipe is closed by the sealing flap in the ‘R’ charger because of differential pressure acting on either side in the sealing flap at the same time pressure diferential acts across the large diaphragm of the three pressure value which pushes the piston unit (Large &Small (Upwards The upward movement of the piston unit closes the outlet port by uplifting of the control sleeve In addition to this outlet port at the top of the three pressure value closes and the inlet port opens . The air from auxiliary reservoir through the open inlet port the minimum pressure limiter the minimum pressure limiter enters the brake cyminders When the pressure in the brake cylinders reaches 0.8 kg/cm2 the minimum pressure limiter gets closed and there after maximum pressure limiter gets closed when the pressure in the brake cylinders reaches 3.8 kg/cm2 with the rise in C pressure in the control reservoir During full brake application the brakes are applied at slower rate than in emergency application BP pressure to be reduced by 1.5 kg/cm2 instead of 5 kg/cm2 Note: At the beginning i.e. when BP is reduced and control sleeve uplifts outlet port –BP from top of the control sleeve reaches U.Chamber control open o atmosphere and some BP thus vent off this causes a sudden extra drop in the remaining BP pressure inside the DV and accelerates the effect of brake application propagating this action through out this action through out the length of the train By this brake cylinders pressure starts to rise. The brake cylinders pressure also acts on diaphragm at U- Controller. A controller minimum pressure limiter and maximum pressure limiter. As BC start to rise the A controller value is closed isolated BP and CR . Also the U controller value is closed and local reduction of BP is stopped As BC reaches 0.8kg. it clses the minimum pressure limiter and now the rising BC pressure can pass through maximum limiter through choke 16 which regulates the rate of BCrising As BC reaches 3.8+- 0.1 come to effect at BP drop 1.5 kg ) Graduated application (see figure) When the brake pipe pressure is reduced in steps for graduated application of brakes the incrase I brake cylinder pressure is at a controlled rate and in proportion to brake pipe pressure reduction As soon as the brake cylinder pressure rises in proportion to brake pipe pressure reduction it causes the pistion unit (large &small) to move down into lap position thereby closing the top outlet port with out opening the top outlet port Thus feeding of air from the auxiliary reservoir to the brake cylinder is cut off this cycle is repeated every time BP is reduced in steps effecting graduated application of brakes iii) Release Stage For releasing the brakes when the pressure in the brake pipe is increased the pressure above the large piston increases thus the differential pressure across the large pisto reduces as a result the piston reduces as a result the piston unit (Large&Small) loves down thereby opening the top inlet port The brake cylinder pressure thus passes through the outlet thorugh the release choke provided as the BP pressure reaches 4.85 kg/cm2 the brake cylinder is almost completely draines and the thre pressure assembly attains its charging / running position again Note: in twin pipe system during succeeive application and relase of brakes air flows from feed pipe to the auxialiary reservoir directly .Thus the brake pipe pressure feeds directly the three pressure value This result in faser rise of brake pipe Graduated Release If the pressure in the brake pipe is increased in steps the relasing procedure starts as before how ever the top outlet port get closed and come to lap position as soon as piston unit (Large & small) moves up due to fall to brake cylinder pressure Pg 27- 29. .. . . . DESIGN & FABRICATION OF TEST STAND FOR SUB-ASSEMBLIES OF D.V’S . Distributive value consists of four major sub-Assemblies .They are: 1. Relay value 2. Bottom cover 3. Choke cover 4. R-charger BOTTOM COVER: This valve has been provided in the bottom of the D.V. below the main diaphragm only its release lever is visible from outside which has one or two holes with which the release wires are tied and the other ends of the release wires are secured on sole bars on either side of the wagon for facilitating operation TEST ACCESSORIES FOR BOTTOM COVER:1. Pressure regulator valve 2. Isolating cocks 3. Reservoirs (25L) 4. Reservoirs (6L) 5.Pressure gauge (0-10 kg/cm2) 8.Bottom cover mounting base 1 2,4,5,6 3 8 9,10 7 BOTTOM COVER R-CHARGER: The R-charger automatically stops further charging of AR when the air pressure inside it reaches 5 kg/cm2 .the work has been derived by cut off valve in DV of stone India Grey sham & co. gets this job done through a choke TEST ACCESSORIES FOR R-CHARGER:1. Pressure regulator 2. Isolating cocks 3. Reservoirs (3L) 4. Reservoirs (57L) 5.Isolating cock with choke 0.8 dia 6. Isolating cock with choke 6.0 dia 7.Pressure gauge (0-10 kg/cm2) 8.R-charger mounting base 1 2,3,6 7,8 9 4 5 10,11,12 13 R-CHARGER - CHOKE COVER: ‘A’ controller charger C.R with 5 kg/cm2 air pressure and simulates the ‘R’ charger to open the passage for the B.P air pressure to reach and charge A.R at the rate of 5 kg/cm2. simultaneously it protects the C.R from overcharging. TEST ACCESSORIES FORCHOKE COVER: 1. Pressure regulator valve 2. Isolating cocks 3. Reservoirs (75L) 4. Reservoirs (10L) 5.Pressure gauge (0-10 kg/cm2) 8.Bottom cover mounting base 1 2,4,5,6 3 7 9,10 8 CHOKE COVER RELAY VALVE: In a Distributor value of Passenger stock a single -stage relay value with a transmission ratio of 1.1 is used instead of side cover. KE distributor value equipped with a relay value has a universal action .i.e. the brake cylinder volume. This means that the same distributor value can be used different brake cylinder sizes and piston strokes with out requiring any special modification (change of chikes etc.) Working of Relay Value Introduction Relay Value K.R.I works in conjunction with the Distributor value type “KE “for Passenger stock Relay. Value which has a high feeding capacity has a universal action as already explained in the main features and maintain the application and release timings as specified in RDSO Specification No 02-ABR-94 of an individual coach. Our principals in Germany who are the original designer of KE Distributor value recommends the use of Relay value with KE distributor value to achieve the application and release timings as per U.I.C specifications Release and running (See Sketch) During release and running position. Aux Reservoir pressure also acts on the top of the relay value and is blocked by the seat V32 from entering in to the Cylinders Other Pressure like BP and CR are charged at % kg/cm2 Brake Application During brake application pressure from Aux Reservoir buits up Cv pressure in the relay value which enters under the Diaphragm through choke D31. Pressure on bottom of Diaphragm lifts the value body (RV17) up thus opening the passage V32. Aux reservoir pressure then enters into the Brake Cylinders Brake Cylinder pressure also enters on the top of Diaphragm assy via choke D32 and as soon pressure under and top of the Diaphragm assy are equal. Value body moved down (force of comp spring acting downwards) and closes the passage V32 The max value of Cv pressure is controlled by the max Pressure limiter in the DV a high controls the max brake cylinder pressure Release During release position first Cv Pressure gets released from the main position of the DV normal release position of DV) Brake cylinder pressure which is on top of Diaphragm assy in the relay value exhaust to atmosphere through open passage V31 (as pressure under the Diaphragm assy is less than the pressure on top this moves the Diaphragm assy down and thus opening passage V31) Disassembly of Relay value (Ref Fig ) - Remove strip (RV -19 _ out of clamping ring (RV -14) using a special circlip piler and remove supporting plate (RV -18) Remove Diaphragm ( RV -13) from the housing and take out value body (RV-17) Take out screw plug (KD -06) and remove O-ring (KD-05) Note: - Do not remove any other screw plugs bushing from the housing Assembly of Relay Value Assemble the relay value in the reverse sequence to disassembly Install the Diaphragm ( RV-13) in such a way that the sealing bead is located correctly in its groove in the relay value housing Note: - Use special nose plier to fix strip (RV-19) into the clamping ring (RV-14) Testing of relay value After assembly /overhaul test the individual relay value on the test bench Testing accessories mounting (Pt no 4A54753) ‘T’ =1 No Pressure reducing value ‘DMV’ = 1No Isolating cocks’H1,H2,H4’ =3 Nos Three way clock with exhaust choke -1 No 0.8mm dia ‘H3’ Choke 0.4 mm dia ‘D’ =1No Pressure gauges 0-10 Kg/Cm2 =3 No Reservoir 3 Litre -1 No Reservoir 25 litre -1 No Procedure: (for your guidance working diagram of relay value is also shown) a) Mount Relay value (3) air tight on mounting base should be plugged air tight Remove Protection Cap (RV -07) b) Adjust pressure reducing value (DMV) to 5 kg/cm2 .Open isolating cock H2 c) Check inlet value seat V32 for leakage by applying soap solution to exhaust port O. There should be no leakage d) Close cock H2 and open cock H1 until Cv pressure is 3.7 Kg/Cm2 (Cv is pressure coming from top cover of DV) and record the charging time in reservoir C from 0 to 3.6 kg/cm2 (it should be 34 +- 2 secs ) The pressure difference between Cv and C shall not exceed 0.1 kg/cm2 e) Check out –let value seat V31 for leakage by applying soap solution to exhaust port O . There should be no leakage f) Open 3 way cock H3 and exhaust Cv Pressure via 0.8 mm dia Choke. Record drop in C pressure from 3.6 kg/cm2 to zero ( should be between 15 to 20 secs ) g) Re-charge the Aux reservoir via cock H2 charge Cv to 3.7 kg/cm2 in small steps via cock H3. Observe pressure gauges Cv and C and note the rise of Cc and C pressure is identical and with out any delay Observe the above by releasing the Cv pressure in steps h) Exhaust all the pressures and remove the relay from the mounting base Overhauling. Overhaul the relay value along with the overhauling schedule of DV and replace the following components on every POH kit of DV approved by RDSO S.No 1 2 3 4 5 6 Part Name Diaphragm Sealing Ring Grooved Ring Sealing Ring O-Ring Sealing Ring Part No RV-13 RV-20 RV-09 RV-21 KD-05 KD-04 No/off 1 1 1 1 1 1 Note: During overhand check other components also for any marks excessive wear or damage. Replace these with new parts KBI CODE RV-08 RV-07 RV-05 RV-04 RV-09 RV-11 RV-10 RV-06 RV-21 RV-12 KD-06 KD-05 RV-20 RV-17 RV-13 DESCRIPTION COTTOR PIN PROTECTION CAP SCREWED PLUG SEALING RING GROOVED RING SUPPORTING RING COMPRESSION SPRING VALVE GUIDE SEALING RING FILTER SCREWED PLUG O- RING SEALING RING VALVE BODY DIAPHRAGM QTY 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 RV-18 RV-14 KD-121 RV-03 KD-169A RV-02 RV-19 KD-170 RV-16 RV-15 RV-01 SUPPORTING PLATE CLAMPING RING SPRING WASHER HEX.HD.VOLT (M12*110) COUNTER SUNK SCREW M3*6 NAME PLATE STRIP SEALING RING CIRCLIP A10 WASHER BODY 1 1 1 1 1 1 1 1 1 1 1 TEST STAND FOR RELAY VALVE TEST ACCESSORIES FOR RELAY VALVE: 1. Pressure regulator valve 2. Isolating cocks 3. Reservoirs (75L) 4. Reservoirs (10L) 5.Pressure gauge (0-10 kg/cm2) 8.Bottom cover mounting base 1 2,4,5,6 3 7 9,10 8 RELAY VALVE PREPARED TEST STAND FOR RELAY VALVE The required parts for the design of Test Stand To prepare a Test Stand we need to having following components. 1. Mounting “T” : 1 2. Pressure Reducing Value : 1 3. Isolating cocks H1, H2, H4 : 3 4. Three way cock with Exhaust choke : 1 0.8 mm dia ‘H3’ 5. Choke 0.4 mm dia ‘D’ 6. Pressure gauge (0-10 Kg/cm2) : 3 7. Reservoir : 3 liter. 25 liter. Mounting “T”: These is stand o which all accessories are mounted, this act as a frame and support other part. The material used for preparing this stand is ………………. We need to be specified about the dimensions of the stand to be prepared. Pressure Reducing Value : Pressure reducing value play a major role. it supplies the required pressure to the cylinder what ever may be the pressure outcome from the cylinder. Initial pressure present in the main reservoir is 12kg/cm2 but the required pressure is 6kg/cm2 for auxiliary reservoir and 5kg/cm2 for brake pipes. Isolating cocks Uses these are used to control direction of the pressure. Here we use three isolating cocks H1= H2= H4= Three way cock: Three way cock is used to allow the pressure in three direction. H3= Choke Choke is small circular body with a small hole in the middle the is used to increase the pressure . we can increase the pressure to required level by using the suitable choke. Pressure gauge Pressure gauges are the devices used to measure the pressure inside the reservoirs her we used tha (0-10kg/cm2) pressure gauge. Reservoir Reservoir are used to store the pressure. As we the pressure plays a major role here storing the pressure is also important . so we use mildsteel cylinder to store the reuired pressure. Here for preparing the testshand we required 2 cylinder volume . 1. 3 liter. 2. 25 liter. For Design the Reservoirs These following steps are to followed to design the cylinder 1. Required volumes are to know first. 2. Dimensions for the required volume are to be calculated a)3-liter we usually don’t find the 3-liter so we need to cut the 5-liter cylinder into 3-liter so we need cut the cylinder to the required dimension 1. Standard length(L1): 2. Circmfrence: 3. Standard Diameter: As we know V = II/4 *D2 *L V= volume in liters. D=diameter in meters. L=length in meters. 3/1000 = II/4 * ()2 * L L2 = mtr. Required length for obtaining 3liter volume(L2)= b) 25 liter As 25 liter is a standard cylinder we need not design or cut its length . its is readily available 1. Standard length: 0.415mtr (415mm) 2. Circmfrence: 0.5597mtr (559mm) 3. Standard Diameter: 0.2768 mtr (276mm) Intermediate plate It is main part of the test stand it can be considered as a heart of the test stand it act like a DV because as we can’t mount the whole DV assemble to the test stand so the intermediate plate is e need to prepare, the part with similar feature of the DV For preparing the Intermediate plate 1. Take a metal block of required dimensions 2. Plot the dimensions on it 3. Perform suitable operation on lt like a) Milling. b) Turning c) Step turning d) Grooving e) Threading(External threading) f) Drilling g) Reaming h) Taping(Internal threading) i) Finishing RESULTS Periodic overhauling of the total air braking system must be done to make the air braking system work efficiently and to prevent major defects and there problems that could arise due to defects in a Distributor valve Railways Air Brake system has a Test stand for testing an assembled D.V. but it does not have test stands for its sub assemblies. The main objective of the project is Design and Fabrication of Test stand of sub assemblies of Distributor valves Many factors are taken into consideration for the Design of test stands for Bottom cover, choke cover, R-charger, Relay valve. Factors are as follows: 1. Intermediate plate with suitable dimensions. 2. cylinders with required capacity. 3. Isolating cocks. 4. Pressure regulating valve. 5. pipes for connecting cylinders. 6. pressure gauges CONCLUSIONS: After completing the above project, we can conclude that test stand prepared for sub assemblies is more useful than the previous( assembled DV) test stand. 1. 2. 3. 4. 5. As time is the main criteria for testing, time taken for repair, replacement Of the DV,s can be minimized. Less fatigue for the worker Rating of overhauling will be increased Testing of each part before assembling is useful for rectifying the defects in respective components Possibilities of certain faults can be eliminated in advance. 6. Wastage of money and manpower can be avoided REFERENCES: 1. Air Brakes system by P.C GUPTA. 2. Manual of Lallaguda work shop. 3. www. Indianrailway.org. Routing 1. Working Principle of Air Braking system • Introduction to BRAKE SYSTEM and its Classification & Components. • Introduction to AIR SYSTEM brakes & Working Principle. • Air Brake System and classification of Air Brakes. • Operation of Presently used Twin Pipe Graduated Release System. • Different Components of Air Brakes System. • Comparison between Air Brakes AND Vacuum Brakes System • Advantages of Air Brakes System over Vacuum Brakes system. 2. Study of Distributive Value. • Distributive Value. • Function of the Distributive Value • Types of the Distributive Value • Operation of Distributive Value (Charging Stage, Application Stage, Release Stage). • Study of sub Assemblies of Distributive Value 3. Functioning of major Subassemblies of Distributive. • Functioning of the Bottom Cover. • Functioning of the Choke Cover. • Functioning of the R-charger Cover. • Functioning of the Relay Cover. 4. Study of Distributive Test stand. • Working principle of the Distributive Parameter • Pressure involved in functioning the DV • Pressure involved in each Subassemblies of DV • Parameter that are to be considered while Testing • 5. Collecting feasible data for the Design of the Relay value. • Data required for constructing the Test stand. • Material used for constructing the Test stand . • Calculating the required volume of reservoir • Design the Intermediate plate & process involved on Achieving it. • Gathering the other Required Parts like Isolating cocks, pressure Gauges, pressures Reducing value , three way pressure value. 6. Mathematics Calculation of the Reservoirs for the Test Stand. • Calculating the diameter of the reservoir for 3liter & 25liter. • Estimating the length of the reservoirs. • Material used for cylinder 7. Fabrication the cylinder. • Constructing the cylinder with design parameter. • Performed the suitable operation on the obtaining the required dimensions • Preventive measurement are taken 8. Marking the required dimensions of the relay value on the Metal block. • Dimensions of the female part(Relay valve) and the male part(DV) are taken • Plot the male dimensions on the metal block (Intermediate plate) • Care is taken for the accuracy as it deals with the air • Take a metal block of 20*20 9. Performing sequential operation on the metal block. • • • • • • • • • Vertical Milling(for accuracy) Turning Step turning Grooving Threading(External) Drilling Reaming Taping Finishing 10. Construction of Mounting Stand for the Cylinder And Intermediate plate. • Dimensions of the stand are taken by considering dimensions of the cylinder and Intermediate plate. • Taken individual length L-shape rods and jointed accordingly with the required dimensions • 11. Connecting Accessories Required parts with hose Pipes as per line Diagram. • Isolating Cocks , Pressure Reducing Value, Pressure Gauges with hose Pipes 12. Inspecting of Designed Test stand. • Test the relay valve on the prepared test stand 13. Giving Aesthetic look to the Test Stand. • Total stand is covered with the Cardboard to give it an aesthetic look • Aluminium l-shape are attached at corner for good look . . . .. . . .’