Water leakage case

a Loco  failed on 3/XI due to water shortage.

Significant water level drop was observed in previous trips. Root cause of water leakage was not detected & loco was allowed with reduced schedule periodicity.

Action to be taken:-

A check sheet should be prepared for thoroughly checking all such locos exhibiting repeated water level drop. Checklist must include all leakage points identified in last three years. A broad guide line is given below:

Loco should be thoroughly cleaned. Power pack, radiator room & compressor area must be intensively cleaned & dried.
Descaling of water system should be done by internally re-circulating cleaning agent.

Checking leakages without ensuring dry and clean engine room is an exercise in futility.

Equalizing pipe (water tank 1 to tank 2), hoses connecting radiators, vent pipes & other water system flexible hoses should be replaced.

Internal leakage from vulnerable areas like cylinder head, block, after cooler, V channel should be identified in cold condition.

External leakage of loco should be carefully checked in dry condition especially Pipe line joints & rubbing points, inside clamp, water jumper etc.

Hot engine test should be conducted & water overflow from expansion tank should be checked, if overflow is observed, expansion tank pressure cap should be replaced after checking chocking water pipe line and temperature differential across heat exchangers & pipe lines.
     Siphoning of water should be again checked after fitment of pressure cap.

Water level drop should be observed every two hours to check water level drop.

Internal water leakage is best checked when loco is left shutdown over night & restarted in morning.
                                     



Locos featuring in repeated water level drop should not be permitted from shed without ascertaining root cause & taking corrective action.

Monitoring of water level drop by exception list should be earnestly done and gradually shed should ensure zero tolerance to water level drop.






           






The quality of a man's life is in direct proportionto his commitment to excellence,
regardless of his chosen field of endeavor.

                                              - Vince Lombardi

 Lube oil leakage.

there is an urgent need to address repeated failures of HHP locos due to premature shortage of lube oil .
40 incidences of lube oil shortages in line have been observed in 2011-12 & 2012-13 (up to July’12). Around 200 cases of lube oil leakages were observed in last 14 months during schedule checking at Shed. Details are enclosed.

Action plan to arrest lube oil leakage:

Cleanliness: Cleanliness of power pack and lube oil pipe line needs to be ensured. Present level of cleanliness is grossly unsatisfactory making it extremely difficult to observe leakages and take remedial measures. Loco must be totally clean to observe leakage/sweating of even a drop of lube oil.
Pre-commissioning: Misalignment in lube oil pipe line should be thoroughly attended during pre-commissioning. Misalignment of pipe line has been found to be major contributor of lube oil leakage. Practices followed in SWR should be implemented by shed.  Supervisors should be deputed to collect the practices followed in leading sheds.
List of vulnerable locations:  Vulnerable locations causing repeated leakages should be identified. List of locations as compiled from shed records is given in annexure. These locations should be carefully checked with the help of check sheet in every schedule. Copy of check sheet is enclosed. Vulnerable locations should be made must attention item during yearly and above schedules.
Trend monitoring of loco with previous trip’s lube oil consumption: Trend monitoring of LOC and lube to fuel oil ratio of the current trip with past records should be done to observe rise in trend if any. Stringent bench marking of lube oil to fuel ratio for Shed out loco should be kept (preferably less than 0.5) and no loco should be permitted to leave the shed above this consumption. Analysis of five months LOFR data indicates that LOFR of 37locos are lying below 0.6. Shed should strive to achieve this value as internal target and progressively bring it below 0.5.

LOFR locos LOFR locos  
≥ 1 16 0.6 to 0.5 18  
1 to 0.8 23 ≤ 0.5 19  
0.8 to 0.6 35

Workmanship and Root Cause: Root-cause analysis of premature perishing of gaskets, hoses etc should be ascertained and corrective action should be taken.
Measurement of liner, ring and piston groove wear: measurement of these parameters should be recorded to find wear of liner, ring and piston grove. Premature wear should be reported to OEM for further analysis.
Valve and valve guide clearance: Using a telescoping gauge, check the valve guide inside diameter. Check that the outside diameter of the valve stem is not less than the minimum limit.
Maintenance of Lube oil separator: For lube oil separator to operate properly, crankcase suction needs to be in a range of from 50.8 mm (2") H2O to 203 mm (8") H2O. If crankcase suction falls outside of this range after engine maintenance work, a thorough engine inspection should be performed to determine the cause. If no obvious cause is found, crankcase suction can be brought back into range by substituting a different size air ejector nozzle. Crankcase vacuum measurement should be taken at full load and speed, preferably after at least one hour of running time as crankcase suction tends to decrease as the engine temperature increases.
explore use oversized piston and oversized ring groove after machining piston groove.( details are in IB, copy enclosed.)
Incorporate best maintenance practices: Best maintenance practices should include:
Colour matching of surface before fitment of gasket.
Banning use of oversized/thicker gasket.
Surface preparation
Pipe alignment and checking contour and bend to ensure that pipe lines are not under stress.
Use of effective clamping to mitigate effect of vibration. Clamp must have soft cushion inside to eliminate biting of pipe lines.
Maintenance of ejector to ensure creation of adequate vacuum. Its periodical measurement.)
Periodical DPT (180days) of identified vulnerable locations prone to crack.
Hydraulic testing of heat exchangers.
Planned replacement of gaskets, hose pipes during 2/3 yearly schedule based on past failure data.



 Check Sheet for arresting lube oil leakage



No loco should be allowed with lube oil external leakage. Following are the vulnerable locations :


Turbo spin on filter steel pipe leakage from brazed area.
Aux. drive gear housing leakage.
Lube Oil drain pipe leakage.
Lube Oil strainer ‘O’ ring deformed and leakage.
Scavenging Pump to filter drum armour gasket leakage.
Scavenging Pump Pressure Plug leakage.
Lube oil cooler to strainer armour joint leakage.
Hot oil detector elbow leakage and leakage from flexible hose.
Lube Oil Cooler pipe line near cooler base lube oil leakage.
Lube oil filter drum plug leak.
Scavenging Pump out let pipe leakage from flange.
Lube oil cooler tube crack.
Lube oil leakage from turbo housing bottom end.
Lube oil conditioning gauge leak.
Lube oil leakage from soak back flange.
Lube oil leakage from turbo soak back filter base.
Lube oil cooler to strainer flange joint leak.
Hand hole cover lube oil leakage.
Lube oil leakage from top deck cover.
Lube Oil Vent pipe to cooler leakage.
Lube oil supply pipe to Gov. inside top deck cover leakage.
Lube oil leakage from pre-lube plug.
Lube oil leakage from OST housing.
Lube oil cooler to water tank vent pipe leakage.
OST housing to cooler vent middle joint leakage.
Main Lube Oil Pump discharge elbow to Lube oil strainer vent pipe leakage.


II. Lube Oil leakage from Power Assembly (whose life are more than three years):

Sign of oil leakage in power assembly seen from air box location wise.
Check condition of baggies filter, if found air box dirty with sand particles.
Piston oil ring side clearance and face to face clearance to be measured when power assy.
removed.

III. Less crank case vacuum (crankcase vacuum should be 2 cm min. in idle and 8 cm    
                 in 8th notch), areas to attend in case of less CCV:

1. Ejector unit nozzle in-accurate size.
2. Top deck cover clip broken or loose.
3. Top deck cover gasket worn out.
4. Hand hole cover gasket worn.
5. Ejector hose and elbow damaged or loose or slip.

IV. LOFR monitoring trip-wise (LOFR should be within 0.5):

V. No loco should be allowed with external lube oil leakage.

Auto shut down (ASD)of HHP locos and action plan.

Review of Last three years Failure incidences indicate that mid section loco auto shut down (ASD) cases continue unabated. Details are given below:

ASD	2010-11	2011-12	2012-13	Total
Electrical causes	4	12	18	34
Mechanical causes	9	26	18	53
Faults not establiShed	17	6	10	33
Total	30	44	46	120

Analysis of causes:

A large number of factors either individually or jointly are responsible for ASD cases. These Factors responsible for Auto shut down of loco have been classified into two groups.

 Electrical causes :  Analysis of auto shut down cases reveals that major contributors from electrical side are AC Fuel pump motor failure(47%); FP relays ,RF contactor and EFCO switch(23.5%);Electronic cards(17.5%) ; cable and plugs(6%) and Radiator fan & others(6%).

Mechanical causes: The highest contributor from mechanical side is Engine Governor-24.5% followed by water cooling system-15%.

Other major contributors are Power assembly -11.3%, Turbo super charger -11.3%, Injection system-11.3%, Fuel oil system -7.5%, Lube oil system -7.5% ,cam gear clutch gear-7.5% and EPD-3.8%.

A significant number of ASD cases remain unresolved due to improper & incomplete investigation.  Root causes of failures were not establiShed in   27.5% of   ASD cases.

Action to be taken:

·        On arrival of failed loco in Shed, it should be checked as per check-sheet. (The copy attached).

·        Maintenance practices should be updated and trip schedule form should include Lube oil pressure  and Low idle RPM checking by sudden notch down of throttle, , measurement of  Governor Shut down gap , oil pressure and delay time of governor, TSC clutch drive performance test, fuel suction vacuum checking, OST value checking

by sudden notch up, Control circuit ground checking. Currently these tests are not being done by Shed.

·        ASD condition should be simulated in Shed and validation of corrective measures must be confirmed.

·        Performance of such measures should be further checked by conducting extended trails and footplates.

The check sheet has been prepared based on root causes of ASD cases reported in last three years. It should be further updated based on experiences gained by Shed in last five years after analysing all line and Shed ASD cases.

Implementation of above check-sheet and defects noticed should be closely monitored.

DA- Check list for auto shut down.

                                                                                         

   

Annexure

Checklist to arrest Auto shut down.

Mechanical causes	Action to be taken	Periodicity of Checking
1.Water shortage from Engine water cooling system and power pack-	a) joint checking with lab as per water leakage check-sheet: Leakages from pipe joints, Drain cock, Armour joints, Radiator core, Water inlet tube assembly, Water pump seal, Water filling pressure cap, Power assembly head to cyl gasket etc to be checked and arrested. b) Water contamination in lube oil to be checked for liner crack by lab. c) water pump performance to be checked by monitoring water pressure.	a) Leakage to be checked in trip and above schedule. b) trip and above schedule. c)30 days schedule
2. Lube oil shortage  a) Due to leakage and oil throwing and low lube oil pressure. b) Less lube oil viscosity.	a)Check Sheet for arresting lube oil leakage  in HHP locomotives issued to Shed vide L/No. Diesel/ Maintenance /HQS& Sheds/30 dated 26 July 2012 to be implemented. Lube oil pressure to be monitored and minimum lube oil pressure should not be less than 1.4Kg/cm2 at IDLE. Sudden notch up and notch down to check lube oil pressure during load test. b) Check lube oil viscosity and it should be 12.4 to 18.3 C/S.	a) Leakage to be checked in trip and above schedule. b) 30 days schedule
3. Governor a) Solenoid coil short or open. b) Oil leakage or shortage c) Drive shaft broken. d) Oil entry in Amphenol plug. e) Linkage failure that not coming back to original position after pressing in 2 seconds. f) Erratic RPM or IDLE RPM is less than 200 +/_ 4. g) Governor oil pressure less than 90 PSI h) Governor Trip plunger seized. i) Governor shut down gap is less than 33 thau. j) Governor Time delay is less than 50 Sec.	a) Checking of solenoid coil resistance in Amphenol plug to be done and provision of surge suppression circuit to be done. b) Topping up of governor oil without investigation to be stopped and checking for contamination, oil leakage as well as foaming to be done. c) DPT and alignment checking of drive shaft d) Traces of oil inside Amphenol plug to be checked e) Free movement of rack and linkage to be checked before starting the loco in all schedule f)Low IDLE RPM to be checked g) Governor oil pressure to be measured during starting. h) Movement of Governor Trip plunger should be checked. i) Shut down gap to be checked. j) Time delay to be checked with the help of cut off cock of water line connection to EPD.	a) & b) Trip and above schedule c)Whenever governor removed and during  3 yearly schedule . d) Trip schedule e) 30 days f) In all schedules g) 180 days and above schedule. h) All schedules. i) Special drive and 180 days schedule. j) 180 days schedule.
4.Cam shaft, cam gear bracket a) cam gear teeth broken ,bracket assembly of bearing of  cam shaft drive and block assembly bearing plane	a) To be checked by lab jointly	a) 6 yearly schedule
5.Turbo and clutch assly. a) Failure of clutch drive assly b) Turbo seizure c) Turbo educator assly jam causing positive pressure in crankcase	a)Clutch drive test to be conducted as given in EMD manual. b) TRD test and temperature monitoring to be done.TPU RPM to be recorded during load test. c) HQ instruction issued vide L/No. Diesel/ Maintenance /HQS& Sheds/30 dated 26 July 2012 to be followed . Crankcase vacuum to be checked and maintained  5 to 8 cm. of water in all schedule.	a), b) and c) 30days schedule
6.EPD and Hot oil detector. a) Malfunctioning of EPD and Hot oil detector	a) Overhauling of EPD and testing of both EPD and Hot oil detector.	a) 2 yearly schedule
7.Fuel system a) Suction vacuum in suction line is less. b) Suction line blocked or no fuel c) Fuel oil pressure <0.5 Kg/cm2 in any notch. d) Regulating pressure less e) Leakage of fuel in fuel system pipe joints	a) & b) Suction vacuum to be checked. c)& d) Fuel oil pressure monitoring and comparing with previous value. e) Leakage checking in all pipe line joints, filter housing.	a),b),c) and d) 30 days schedule. e) Trip and above schedule
8.Injection system a) Mechanical unit injector rack jam.	a) Checking of injector for free movements.	a)90 days schedule
9.OST a) Wrong setting of OST value	a) OST should be tested on test bench and performance of OST to be checked by pressing Gov linkage manually .Sudden notch up/down from idle to8th notch during load test to be done.	a) Test bench to be fabricated and to be tested in 6 yearly
10. Auxiliary  Gen. shaft breakage a) Mis alignment of Aux Gen drive shaft.	a) Auxiliary Gen drive shaft run out to be checked.	a) In 180 days schedule and all pass locos to be covered in priority by introducing special drive.
Electrical causes	Action to be taken
1.Control a) Computer power supply failure due to faulty PRG and PSM. b) Misbehaviour of DIO cards. c) Faulty DIP 80 card for MUX circuit failure. d) Water entry in ECC3 causing shorting of 823 C ,833B plug, TB 83 B and DIP card. e) Plug pin push back in 823 C ,833B plug and Amphenol plug.	a),b) and c)  Check for low voltage ground fault. Check PRG and PSM output, Digital I/O  for DIO and MUX circuit checking in EM2000.  d) Check door gasket condition and ensure door locks of ECC3 working properly. e) Ensure proper fitment at the time of plug fitment by checking solenoid output signal in EM2000 screen.   Card handling as per HQ instruction issued vide Diesel/Maintenance/HQS & Sheds/30 dated January 31, 2011.	a),b)  in trip schedule and c) in 90 days schedule. d) In every out going loco. e) Whenever maintenance of plugs carried out.
2.Switch and CB a) MUSD and EFCO switches failure . b) Short circuit  in circuit related to FPB, Control and Local control Circuit breaker. C) Malfunctioning of LWS	a) Multiple operation of switches and test bench test at section. b) Current measurement in Circuit breaker terminals. Ground checking C) Test bench test of LWS	a) & b) Checking in trip and above schedule and testing in test bench in yearly schedule. c) yearly schedule
3.Harness a) Low voltage ground may cause input circuit high	a) Control harness should be checked for ground. Special drive to be carried out to ensure protection of cable insulation with nylon spacers and sheet inside ECC1,2 and 3	a) Ground checking in 90 days schedule
4.Fuel pump motor a) Bearing seizure or inverter failure	a) Bearing temperature and unusual sound to be monitored. b)Fuel pump motor current trend  monitoring (Value should not exceed 7.8 Amp). If more than the rating value observed, it should be investigated.	a) & b) Trip and above schedule
5.Cooling system Radiator fan failure a ) Bearing failure b) Fan blade breakage. Rad fan contactor c) FCS tips brazing or interlock failure. d) FCF fail to pick up due to  armature jam. e) FCF coil open circuited. Fuse of RFC burnt or CB tripping. f) Radiator fan fuse burnt g) Radiator fan circuit breaker tripping h) Cable burnt and terminal lug loose or burnt.	a) Check radiator fan bearing unusual sound and monitor bearing temperature. b) DPT of fan blades c),d) & e) Cooling fan test through LCC check status of contactor for FCS contact brazing and inter lock failure as well as FCF contactor for armature jam and coil open circuit.RFC  test bench test to be done .Application of silicon grease. f) Fuse and RFC terminal checking for overheating sign. g) Check down load and monitor during load test. h) Cable checking for deteriorating insulation and overheating sign.	a) 30days schedule. b) 3 yearly schedule c),d) & e)Cooling fan test to be done in all schedules and test bench testing in yearly schedule. f) Trip and above g) Load test h) Trip and above
6.Relay failures a) Operating coil failure or Contact tips burning of SDR, FPM ,MCB and EFCO relays	a) Coil resistance checking and mv drop test. Relay maintenance instruction issued by HQ vide DSL/Maintenance/HQ/Shed/30 dated January 1st, 2013 to be implemented.       b) Parallel shorting of relays	a) 30 days schedule.

 Involvement of laboratory in addressing reliability issue has paid reach dividends especially in air brake and there is an urgent need to replicate the experiment in other sections/areas. ACMTs have to act as nodal Officer’s for quality control, failure investigation and certification of testing & maintenance practices.

1. . Labs must identify and analyze root cause of failures. Comments must cover:

·        Material issue- specific material faults/ defects /& why they develop? What checking  should be done at the time of fitment to arrest subsequent material degradation & suggested in-situ checking

·        Fitment issue- what specific acts/mistakes are leading to component failures? Factors like poor knowledge and skill level should be identified & action plan suggested.  Testing & cross-checking knowledge and skill should be jointly done.

Sr. DME. Dsls must review lab presentation personally to ensure meaningful analysis and recommendation.

2.    Vendor wise performance record to be kept for all mechanical components. Data base of failures ( line, Shed and OVH failures before 2 yrs service life) to be kept.

3.    Examination of released components: All released components after stripping during OVH should be minutely examined.  root cause wise analysis of each component which exhibit deterioration/damage should be done. Specific suggestions should be given to section so that service life can be at least doubled from present level.

4.    Lab exception list:  . Exception list should be updated every fortnight. Action taken on items featuring in exception list should be recorded with signature of the supervisor of the concerned section. Moreover, abrupt changes in viscosity and spectro report must be highlighted in the exception list.

   ACMTs must weekly review testing practices.

5.    Water system leakages- Vulnerable locations have been identified. Equalizing pipe to be converted to 1 inch dia and to be replaced during M₂₄ schedules to avoid choking. Water jumper brazing leakages, sign of seepage, hydraulic testing to be ensured by Lab . ACMT in consultation with other labs should issue list of root causes for water related failures. All Sheds must attend each loco during major/medium schedule accordingly, so that water leakages don’t happen during running schedule.

6.    Lube oil leakages- Vulnerable locations have been identified. ACMT should issue list of root causes for lube oil leakages. All Sheds must attend each loco during major/medium schedule accordingly, so that lube oil leakages are not encountered during running schedule.

7.    List of warranty claims records should be maintained for all prematurely failed mechanical components.

8.    Metallurgical investigation: Failed components are currently not being metallurgically examined. All major cases of component failures are to be analysed in major labs as comparative metallurgical testing facilities are not available in Shed.

9.    Examination of failed components by lab: All cases of line/Shed failed component sample are not sent to lab by concerned sections. Sr.DMEs must enforce discipline & make suitable maintenance system.

10. Record of corrective action: Faults recorded by lab are advised to section but corrective actions taken & results obtained are not recorded. Lab must record the same, message loop must be completed.

11. Periodical checking of all mechanical components of stores & section should be done by ACMT & his team. Irregularities noticed should be reported to Sr.DMEs & HQ.

12. Feedback to RDSO/DLW/OEMs: Product deficiency observed after analysis should be reported to firm & Inspecting Agency.

13. Focused testing of failure prone components: List of items which have failed prematurely should be compiled by lab. All such identified components should be subjected to two stage test, one during material accountal stage & another before fitment. This will ensure that material related problems do not recur. All mechanical items must be pre tested by lab before fitment irrespective of previous inspection.

14. Computerization of lab records: All lab record keeping must be computerized in all Sheds. One PC for LMG lab should be provided for record keeping.

15.  Air brake section: Air brake valve overhauling & lab involvement in testing & auditing maintenance practices should be replicated in all Sheds in all mechanical sections. This is the roadmap to be followed.  It was again confirmed by ACMT that no defect has been observed in old released rubber kits after examination of stripped Air Brake valves taken for OVH.

16. NDT:. Rejected materials should be reported to Firm for corrective action. Reason of rejection of old material should be reviewed and proper screening procedure to be devised to weed out defective material during testing of new material itself.

In case of Cam Gear and Split Gear, severity of pitting should be quantified. Rejection should be done during Shed detection preferably M₂₄/₄₈ to avoid line failures.

For traceability of rejected components, section should put ID mark by either itching or punching.

   Each Shed should devise new/additional testing methodology based on present rejection of old materials during NDT. Components to be zyglo tested as per OEM should not be subjected to DPT and prevailing practice to be stopped with immediate effect. DPT to be done only after proper cleaning e.g. grinding and polishing of welded surfaces etc.

Rejected material should not be returned to section, proper record should be maintained and after keeping samples, rest materials should be scrapped and deposited in stores to avoid recycling.

Main/ Con Rod Bearing to be tested as per MI only.

17. Lab testing practices: List of practices discontinued should be compiled and reintroduced. ACMTs must confirm the same.  Shed has started :

·        Radiator fan blades visual checking during minor schedules & dye penetration test M-2 and on ward schedule.

·        Suspension bearing oil checking in every schedule. Ultra sonic testing of suspension bearing.

·        Crackle test of Fuel Oil from cylinder head leak-off to detect nozzle sleeve crack.

·        Spectrographic analysis of Compressor oil from M₂ schedule onwards.

·        100 % checking of gaskets.

Other Sheds must start or confirm the same if already being done.

18.Analysis by Lab:

Water pump failures are due to

• Loose castle nut, free rotation of impeller, breaking of split pin
• fitment of impeller without ensuring interference and dimensional accuracy
• Poor Quality of split pin and handling of split pin.

Shed must submit action plan to arrest above root causes.

Riser pipes initially fitted at RB are susceptible to failures either due to material defect like lap or fitment fault. Shed should identify the root cause and advise OEM accordingly. All RB locos to be attended in next M₄ schedule for water riser attention.

Issue of poor quality of High pressure joint sheet was reported. All such inferior gaskets not conforming to specification and prone to failure must be rejected. However, it must be ensured that gaskets are fitted only after proper surface preparation and blue matching. Surface irregularity must not be covered by gaskets.

Gasket Specification should be collected and minimum testing facilities should be developed at Lab.

Procurement of Rubber Component should be done in split up lot only and as per six monthly requirements. Suitable clause should be incorporated.

Brainstorming after each failure must be conducted and best fitment and testing practices of leading  Sheds should be examined. List of suggestions given in current month should be shared with all Sheds

Leakages in lube oil system.

Large scale repeated leakages in lube oil system especially pipe lines and hoses in   locomotives has become point of extreme concern. Review of recent failures indicates systematic recurring weakness in following areas.



 LUBE OIL SYSTEM FAILURE  
  ITEMS  
Sub Assembly Pipings/Joints Gasket Stud & Clamp Total  
Centrifuge 1 2 3 6  
Strainer         2 1 3  
Turbo         1 1  
L/Oil cooler 1 3 4  
Regulating valve 3 3  
Lube oil filter 2 2  
Engine Governor 2 2  
Drain pipe 1 1  
Turbo Filter casing crack 1  
Total        13 6 3 23  

Preventive measures as outlined below must be started by shed with immediate effect.

Check list containing identified leak prone points as mentioned above should be prepared. Special attention should be paid on pipe lines and joints of strainer, centrifuge, turbo & lube oil cooler. A drive should be launched to check condition of lube oil system in every schedule.


Loco must be cleaned thoroughly and power-pack should be wiped clean and kept dry. No oozing, seepage should be permitted from any joint. Leakages can be detected only on clean background


Lube oil hoses should be replaced/ recertified in M12 and above schedules.


Lube oil hoses kit  for non abrasive hoses should be stocked and used by  sheds.

Old end fittings should not be reused by sheds. Only hose pipe with integral end fittings should be used. All rubber hoses along with end fittings should be hydraulically tested under water at 10 kg / cm2 air pressure

Hose coupling threads must be cleaned, degreased and coated with thread locking compound before assembly.


Piping: The layout of pipe line should be laid in stream line fashion exactly similar to DLW manufactured/DMW RPP locos. There should not be any sharp bend or rubbing in pipe lines. T gauge should be used for ensuring correct gap and alignment for joining pipe.

Clamping: All clamps are to be renewed during major schedules. Welding over existing welding should not be resorted to. Clamps should be rigidly fixed and soft Gasketting material should be used before clamping pipes/hoses

Colour matching of surface: Whenever two surfaces are to be joined either with or without gasket, proper lapping and colour matching of surface should be ensured. Surface condition should be checked and restored if required.


Gaskets: Condition of old gasket will yield valuable clue regarding poor surface condition, sharp edges, over tightening and premature perishing.  Causes of these should be attended before new gasket is fitted. Gasketting compound should be used for attending surface imperfections. Gasket must be visually examined and tightened uniformly.

Over tightening:  Whenever any leakage is observed in shed, staff simply over tighten the component and allow it in service. No over tightening should be permitted, if leakage is observed then component should be dismantled and cause of leakages, damaged thread, surface or gasket should be attended.


Leakage checking: Leakages are best checked when loco is on load box test and run for some time. Lube oil leakage tendency is very high at higher temperature due to reduction in viscosity at elevated temperature. Crank case exhauster motor can be stopped for 30 seconds and lube oil leakages can be observed.

Training and acceptance level: Sectional staff and supervisors must be trained and counseled to ensure leak free locomotives. Significance of the objective must be understood by all of them.

Progress of the drive and action taken should be monitored.




Annexure

Hose and Fitting care

Component Inspection: Prior to assembly, a careful examination of the hose and fittings must be performed. All components must be checked to ensure that they are the correct type, size, and length. The hose must be examined for cleanliness, obstructions, blisters, kinks, cracks, cuts or any visible defects. The fitting and sealing surfaces need to be inspected for burns, nicks, corrosion or other imperfections.

Minimum Bend Radius: Particular attention must be given to prevent sharp bends at the hose connection to the fitting. Any bending during installation to less than the minimum bend radius should also be avoided.

Proper Connection of Ports: Proper physical installation of the hose assembly requires a correctly installed port connection ensuring that no twist or torque is transferred to the hose when the fittings are being tightened.

Elbows and Adapters: These are provided to relieve hose strain. Only lab tested forged component should be used.

Routing: The hose assembly should be routed in Stream line manner.

Hydraulic Hose Assembly Care

Lengths: Unnecessarily long hoses can increase pressure drops and affect system performance. When pressurized, a hose that is too short may pull loose from its fittings, or stress the fitting connections causing premature failures.
Visual Inspection: Any of the following conditions require immediate shut down and replacement of the hose assembly:

· Fitting slippage on hose.
· Damaged, cracked or charred hose.
· Cracked, damage or badly corroded fittings.
· Leaks at fitting or in hose.
· Kinked, crushed, flattened or twisted hoses.
· Blistered, soft, degraded or loose covers.

Function Test: Operate the system at maximum operating pressure and check for possible malfunctions and leaks.

Hydraulic System Storage and Protection

Hose Sleeves: Sleeves are designed to protect hoses from abrasive wear and other hostile conditions. They simply slip over the end of a hose assembly, or they may be spilt to allow them to be installed around a hose assembly already on equipment. Hose covers are generally made of high strength fabric, and coated with appropriate materials to resist chemicals, heat, particles, moisture etc.

Hose storage: Temperature, humidity, ozone, sunlight, oils, solvents, corrosive liquids, insects, rodents, and radioactive materials can adversely affect hose products. Hoses should be stored in a dark, dry atmosphere away from heat sources, electrical equipment, and the above adverse elements. The ideal storage temperature for rubber hose is +50°F (10°C) to +70°F (21°C), with a maximum of 100°F (38°C). The date of manufacture of the hoses also needs to be checked.

Hose Storage Life: Hoses must be replaced in M24 & above schedule. No hose older than one year should be fitted.

Hydraulic Hose Assembly Care


The date of manufacture of hoses is generally marked on the hose and other information is provided, for example:
· R1 ~ 2Q/05 marked on a hose shows it is a single wire construction hose made in the 2nd quarter of 2005
· R2 ~ 4Q/05 would denote a two wire construction hose made in the fourth quarter of 2005.

Tips on Hose Assembly Care and Maintenance

Always clean fittings before connection.
Always ensure caps and plugs are fitted on hoses when not in use.
Store hoses out of sunlight. Hoses left in direct sunlight will degrade and high pressures will be generated when oil expands in hose making connection difficult.
Use protective tape, anticorrosive coating to protect fittings from corrosion.








             





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