turbine issues resolution (1)

8/3/2019 Turbine Issues Resolution (1)

1/34

SESSION-1

STEAM TURBINE & AUXILIARIES


2/34

Problem Measures Taken

1. A lot of matching is required at site at matingsurfaces like wall-girder, packer to module etc, due tolack of surface finish during manufacturing stage.

This increases overall cycle time for assembly at siteand wastage of man power. The same is to beensured during manufacturing stage to minimize sitematching. .

Birsinghpur and other sites.

At site, girder to endwallblue matching can beavoided, 0.2mm feeler gaps

can be allowed. Tighteningof bolts and seal weldingwill suffice. Anchor platesmatching will have to bedone at site. Formaintaining catenary of

machine, packers seatingsurfaces may have to beblue matched at sites.

2. LP inner outer and LP inner inner casing axial

keys thickness finalized during shop assembly notmatching during erection due to permissible siteadjustments. Hence it is suggested that the axial keyare also to be finalized at site i.e. over size keys areto be supplied along with set temporary keys.

Birsinghpur and other sites.

Minor adjustments can be

done at sites. Oversizesupply of keys is notrequired.

However, sites can givemore detailed feedback inthis regard.


3/34


3. The auxiliary coupling bolts for HP/IP and IP/LPcouplings are supplied 08 nos. and 09 nos.respectively. During swing check at HP front after

stretching of supplied aux. coupling bolts andrechecking the same after tightening of all thecoupling bolts (after reaming/honing and finalalignment), deviation observed from initial valuesachieved. This leads to re-opening of IP casingand face matching of IP coupling. Hence it is

suggested that total no of auxiliary couplingbolts(16 nos. for HP/IP and 18 nos. for IP/LPcouplings) are to be supplied to check the swingvalues at HP front with stretching of all thecoupling bolts to avoid this problem.(this problemleads to delay in turbine box-up by one month)

Rihand, Birsinghpur

Already implemented forall future sets.100%auxiliary coupling bolts

will be supplied


4/34


4. STG deck inserts (MechanicalEmbedment), Drawing No.2-13100-87156Rev 01: Part nos.05 to 118 have been

shown as customer scope. This being anEPC contract it is in the scope of the region.Part no.95 (Quantity 5 nos.) plate100X250X600 & part no.96 (Quantity 4nos.) plate 100X200X300 is not so easilyavailable and are difficult to fabricate.

Birsinghpur, Sipat, Bellary

Unit has agreed to include 100 mmsize plates in their scope of supply.Such special plates generally not

available will henceforth besupplied from unit.

5. Implementation of BOI such as Insulationof Turbine and associated piping needs tobe improved. In fact the type of insulationmay be changed from present spray type to

castable or ready to assemble insulationpads in order to avoid environmental /health issues.

Ramagundam and other sites

Can be implemented on customerdemand against cost differential.Ceramic type blanket insulation forturbine has already been offered for

2x250 MW Neyvelli project as percustomer requirement at additionalprice.


5/34


6. Special Auxiliary Bearing for No-1journal for SWING CHECK for 500MWset may be designed & supplied by mfg.unit.

Talcher and other sites

Use of device made by PSWR, as analternative to aux. bearing under trialat Rihand & Vindhyachal. Onsuccessful feedback from site, PS &STE will review and decide for future

7.Site suggested that the thermalinsulation (Glass Wool) supplied for

turbine and turbine piping etc. should beof the same density. It is very difficult forsite to store the glass wool density wiseseparately & during actual use of thewool it is difficult to ascertain theerectors people for taking the wool of

required density. Also site should be ableto pick up the wool as and when requiredfrom the vendor.

TDL Panipat

Isolated case.

For all other projects, supply, storageand application are in vendors scope.

Suggestion of workshop participants forusing common density instead of 100 &150 kg/m3 at present has also beendeliberated with PEM representativeattending workshop and participants

were conveyed various constraintsagainst this suggestion.


6/34


8.Radiographic test requirement shall be reducedfrom 100 % for all the piping in TG Integralpiping. Instead 100% RT shall be for Jacking oillines and other lines, only 10% shall be adopted.

This will save lot of inspection time and thus toachieve Milestone readiness in advance

Bellary

Such requirement is as per NTPCtender document. Unit informedpresent FWS addresses 10% to100% requirement.

Bellary site to provide specific detailswherein they desire RT quantumreduction for consideration of theunit.

9.Governing system, hydraulic governing , view

glass is provided to know the bellow conditionduring operation. In old units, toughened glass isprovided compatible to CF system. Recentprojects acrylic material is been supplied which isreacting with CF resulting in softening andleakage.

Site has now covered with metal sheet of 5mmthickness and Unit to provide quality glass.

Same type of problem is faced in CF 32bar filtervent glass. These vent glasses also need to bechanged with toughened glass.

Talcher -3,4,5&6

Site participants informed that in

210/250MW sets, these are not beingprovided and unit can consider needof uniformity, whether blanking canbe permitted for 500MW sets ortoughened glasses compatible to CFsystem will be provided. Unit will

deliberate on same and take suitabledecision based on workshopfeedback and intimate concernedsites accordingly.


7/34


10. Package no. 75704/1 (LP casing assy.) whichincludes loose items of LP turbine usually got delayedleads to delay in LP casing assembly in turn causingover all delay of the project. Supply of the same is to

be ensured during dispatch of pedestals itself.Birsinghpur and other sites

Raw material receiptconstraints, temporarily delayedsupplies for a while and suchsituation is being avoided now.

11. LPBP rack fittings and EHTC block internal locknuts found loose requiring readjustment of

characteristics at site. Locally arranged at site.Mejia

Feedback has been given toShop and Quality for the

needful. Improvement neededin Packing & dispatch

12. TG integral piping supplied by vendor of sizes50mm Nb and below could not be bend at site withthe conventional Hyd. bending machine. Crack foundin the Jacking oil line during bending. The same

bending machine has produced perfect bends forpipes supplied for seal oil system by HWR directly.ELBOWS were used and thus causing great increasein welding joints and delays.

Mejia

Elbows supplied by vendor M/sBend joints, Bhopal. Bend testwill be included in Quality Plan.Feedback is being given to

CQS Bhopal to ensure bendability requirement is being met.


8/34


13. LPBP stop valve servomotor oil leak duringfirst charging The 3 no bushes for servo bottomlong studs was found protruded and the O ring

supplied found not endless and damaged. Thebushes were machined and new O ring fromcustomer arranged. Services of HWR technicians(for unit-1 overhaul) were used. Repetitive for bothvalves and control valve also developed leakagesduring operation

Mejia

Input will be obtained fromtechnicians who visited Mejia siteand will be deliberated in RCA

committee.

14. EHTC of Governor System found defective.The HWR technicians could not rectify theproblem. The small spool rod ( between plungercoil to the piston top ) found bend. After makingthe same straight the EHTC could be made

operative. However problem reappeared again.Mejia

EHTC coil has been brought bysite representative for inspectionand rectification at Haridwar.Rectification done.

Site to give feedback to Unit andCQ whether problem is resolvedand need further help, if any


9/34


15. Leakages from governor components. TheTrip valve bottom flange, all the test valves of

ESV & IVs, Speeder gear etc is having oilleakage. The quality of sealing chords needto be checked. The leakages within a veryshort period of operation is causing concern

Mejia and other sites

This is being taken up in RCAcommittee. More care will be taken

during assy. & testing.Additional quantity of O-rings andchords will be given to sites ascommissioning spares as requested byparticipants.

Sites to contact Haridwar unit for their

requirements and CQ if required.


10/34


16. IPCV &IV-1 problem of operation. IV-1found closing after full opening during firstcommissioning The coupling end square nut

length was increased by ~4mm to get thecorrect value and servomotor assy. IPCV 1found having free actuator movement beforeopening of valve, The same was rectified byintroducing a 3 mm washer in the coupling.Also the valve found mal functioning. The pilot

top bearing found damaged ( with ballsfalling from race). A new equivalent bearingwas procured locally.

Mejia and other sites

Shop record of coupling dimension tobe sent to site.

Cap nut sizes and coupling logsheetwill be provided to site prior to erectioncommencement.

Identification will be more clear fromunit i.e. Left, Right, Nos. etc.


11/34


17. Seal steam fouling with pedestal casing guidekey block. The Key block was ground toaccommodate the seal steam pipe also the

additional bends/elbows were used to reroute theseal steam pipe to gland.

Mejia, Ib Valley

Drawing modified.

18. In ST front bearing pedestal, each of the fournos. holes provided in the yoke (itemno.32) for

fixing parting plane bolts (itemno.33) are offsetwith respect to the respective threaded holesprovided in the pedestal parting plane by 7-8mm. Due to this, the process of assembly/disassembly of the yoke is cumbersome/complicated & time consuming for site. This is

related to a vital component and hence totalinspection and quality control should beexercised prior to dispatch.

New Parli

This appears to be error at sitesince the cap is being sent

assembled at works. Afterdismantling at site, the bearingcap might have beenassembled in reverseorientation.

However, unit shall obtain

further feedback from site inthis regard. CQ will alsofacilitate the same.

P bl M T k


12/34


19. Foundation bolt (M64x1580mm) of drg. no.0124-04-11000, threads of one no. bolt not turnedproperly and hence threaded properly and hencenut could not be threaded up to required depth.

Haridwar representative visited site & grindedlocally

Parichha

Protection of threads wasinadequate. Matter discussedwith Dispatch section to ensureuse of plastic net and buffer

between bolts to avoid collisionduring movement.

20. Outer face of inlet insert of HP insert assembly(Drg no. 1-10514-14000) outside the sealing ring

area is uneven up to 1mm due to damage in itsouter periphery all around its circumference.Haridwar representative visited site & rectifiedthreads

Parichha

Adequate protection to thesurface shall be ensured from

unit.

21.The axial clearance between the groove given inthe bearing pedestal and the casing protrudingportion is 10mm.(zone 9&10L of drg no. 0-11801-01000). Due to casing protruded portion not beingchamfered, the clearance is less than that isrequired. Casing area grinded to achieve therequired clearances

Parichha, Unchahar, Rihand

Feedback shared with CFFP totake care of additional materialin future.

During discussions, this wasagreed to be taken up in RCAcommittee with involvement ofGM(Q), CFFP, Haridwar.


13/34


22. Radial clearance of 3 mm between casing &pedestal (section-AA of drg 0-11801-01000) wasto be maintained but when casing was aligned

the radial clearance was 0mm on one side and 5mm on the other side. Pedestal grinded toachieve the required clearances

Parichha

During discussion, it has beenagreed to be deliberated inRCA committee.

23. The 6th, 7th & 8th stages of LPT blades of LPinner-outer casing (Drg No. 9-10304-12000),bottom half on both rear and front sides, havedents on its surfaces. Total blades were 27 nos.Haridwar team visited site & rectified blade dents.

Parichha

Feedback will be obtained fromtechnicians who visited site.

At Unchahar site the problemhas not been repeated.

24. The taper hole diameter of 20mm (section-EEof drg no. 0-10612-01000) of IP inlet insert wasdrilled but the hole for leak off is not provided inlower IP inlet insert Haridwar team visited site &drilled the required holes

Parichha, Unchahar

Human error.

QC checks introduced in routecard.


14/34


25. Item 48 LP front wall of drg no. 0-10739-01000 is fouling with LP radial key blockassembly. The assembly of key block has been

done as per drg no. 0-10744-01000 of LP casingassembly. The stiffener plate were cut downsuitably so that side wall could be assembledwith LP girders

Parichha

Isolated case.

Sites to provide additionaldetails like sketch, photographsin such cases for betterunderstanding and resolutionfrom unit.

26. In section-QQ of LP casing assembly (Drgno. 0-107-4401000), axial keyway width for (onekey out of 4 keys) after assembly of girder andfront wall is 49.98mm but key supplied are ofwidth 43 mm. 1 no Key of 52mm was supplied byBHEL Haridwar

Parichha, Unchahar

Additional QC check to beincorporated

During deliberation, it wasagreed that this will bediscussed in RCA committee.


15/34


27. While assembly of LP inner -inner casing , 25nos. of studs were fouling with inner casing tophalf (Drg no. 0-107-43-04000). Also holes/slot to

be provided in LP inner casing upper half forlocking of washer is absent. Moreover, LP inner-outer casing bottom half along with inner-innerhas been transported without jack bolts Holes ininner-inner casing upper half provided for partingplane studs be enlarged by 2-3mm to removefouling of casing. Haridwar team rectified theproblem

Parichha

Checking at shop afterensuring 100% use of allfasteners.

Jacking bolts assembly fromshop will be ensured beforedispatch.

Feedback of unit techniciansvisit to sites will be utilizedtowards preventive measures.

28.LP shaft seal: The slots provided for fixing ofkeys have depth 10-12mm against 25 mm(Drgno. 0-107-10-30014) Depth was increased bygrinding / cutting the material & achieve propermatching

Parichha, TDL Panipat

Feedback shared with QC-SC.

Drg clarity has been given to

subcontractor and beingrevised for betterunderstanding.


16/34


29. In section-BB of LP inner-outer casingassembly (drg no. 0-10741-04000), aftercentering of diffuser it was observed that holes

provided were not matching with that of LP inner-outer casing. 15 nos. of holes were not matchingon Generator side and 5 nos. holes on Turbineside. Holes in diffuser were enlarged to removethe mismatch in centerline of the threaded holesin inner-outer casing.

Parichha, TDL Panipat

Trial assembly of diffuser isdone at works with allfasteners.

Sites to give feedback withdetailed sketches for unitunderstanding showingmismatch locations and extentof the same.

Sites to adopt suitable wedging

and trials to get the bestassembly.

30. The key way provided in the casing does notmatch with keyway provided in IP inlet insert, if

alignment is done as per drg no. 0-10612-01000.Separate keyway in casing to matchcorresponding groove provided in IP inlet insertwere made

Parichha

Drawing shall be reviewed toprovide better understanding

and to avoid similar error infuture.



17/34


31. Aux. Oil Pumps supplier-Mather & Platt, PuneIn Unit No 3 during pump in service abnormalnoise was noticed in Pump Sl.No.43805001/1,Pump was opened for inspection & following

observation made - Impeller locking nut with shaftwas not found locked properly resulting in locknut getting loosened & impeller rubbing withpump casing at bottom side.- Pump back plate LG-2 holding brass sleevefound cracked near grub screw for lockingpurpose- Thrust ball bearing found jammed resulting inabnormal sound during pump running.- Pump back plate (cracked), brass sleeve &bearing required replacement.- Pump Sl.No 43805001/2 was opened to checkImpeller locking & Impeller casing. (Pump casing)

was found cracked on mounting flange at topsideCasing replaced from Pump Sl.No 43805001/3.

Rihand

Interaction done with supplierto prevent recurrence. CQSecunderabad is beinginformed for needful.

Quality plan shall be reviewedto avoid repetition of suchevents.



18/34


32. In Turbine as well as Generatorcoupling faces, coupling radial,Journal radial run outs observedbeyond 0.02 specified Engg.

requirements in Unit No III & IVRihand and other sites

Matter has been taken up in RCAcommittee and interaction with sites andunit will continue.

Run out values beyond permissible limits

sites have to inform through email /fax/telephone to Engg and QA of Haridwarprior to taking up any rework.

Unit will depute representative to analysethe issue and to know differences, if any inmeasurement practices at shops and

sites.

33.Three(3) nos. holes of LP casingbase plate were sent with diameter.66mm instead of diameter.78+1mm.Pkg no:75101,item

no:02(drg. No-1-10723-25000)Required size holes were made atlocal workshop. Sometimes it is verydifficult to get the facility for machiningsuch a heavy job at site.

Talcher

Isolated case


19/34


34. No clearance between the Hyd.Barring Gear wheel(pgma-11501) &guide cover(item no-11 of 0-11653-27000) of front pedestal cover. Coverbore dia.475mm, barring gear wheeldiameter. 480mm. Incompletemachining. Required bore diameter onthe cover made by grinding at site andclearance achieved. Very difficult to

achieve required. machining by manualgrinding - Talcher

Missed operation is due to humanfailure. QC took care by making a checklist in advance.



20/34


35. Only one set of O-rings (item no-02&03) &sealing rings (item no-05&06) for hyd. Test & steamblowing arrangement of valves are supplied for allthe units. Pkg no-75319drg. No-1-12023-05000,1-

12024-05000,1-12025-05000,1-12026-05000,1-12050-25000 & 1-12062-01000. Required Materialsarranged at site. These consumables are requiredto be supplied by Mfg. Unit . One set for each unit isessential for smooth & successful conducting oftests.

Talcher and other sites

Agreed

CBOM for 250 / 500 MW setsshall be revised.

In the meanwhile, present

running sites can get thesame by putting request toHaridwar unit.

36. Edge of inlet pipe of ESV casing was not perfect(tapered face). Difficult in joint fit-up. Edgecorrection was made perfectly by manual grinding.Perfect machining is to be carried out at works.Delay in erection activities due to rectification work

Talcher

Additional care shall be taken byunit.


21/34


37. Assembly problem of IP Turbine due to supplyof wrong fitted keys & spacers. Required materialarranged by Haridwar unit & correct assembly of

IPT completed successfully at site. During packing& dispatch correct material/ parts to be identified &supplied for the equipment.

Talcher

To avoid mix up properidentification shall be marked onkeys and packers.

38. Face run out of and parallelism problem facedat TAPP for LP 1&2 rotors at all four faces. Thesame has been corrected at site. Same is to beensured during manufacturing/ slow speedbalancing at unit.

Tarapur

Feedback noted by unit.

39. Mismatch between Equipment drg and

Customer layout drg. have been observed in manycases e.g. PW Unit, Oil Supply rack for ESV /CV,Turbine Cladding, Seal Oil in Oil Canal, CRH &HRH Piping Support EP.

Tarapur

Problem due to customer

drawing mirror image betweeenUnit 3 and 4.

Feedback noted by unit.Drawings of Tarapur shall becorrected so as in future similarsets, problem may not recur.


22/34


40. Control Oil Pump (Imported from KSBGermany) not developing pressure. Onepump has been sent to KSB Pune for

testing. Results awaited.Tarapur

Being investigated by vendor.

Site informed likely delay in oilflushing activity

41. In LP shaft sealing, the dimension E ofkeyway is 29mm whereas E of key is 42mm. (drg. No. 0-107-44-18000)& (drg. No.0-107-64-18000)

7 nos. keys machined

TDL Panipat, Parichha

Proper sequence of operation to befollowed by sub contractor. Feedback shared with QC-SC

42. In LP casing assembly, there ismismatch in holes of inner guide plate ofdiffuser U/H & LP shaft seal compensator

of the order of 3-4mm in all holes .The holeswere enlarged

TDL Panipat, Suratgarh (all units)

Drawing of compensator to bereviewed to include the tech.requirement

M/s Lonestar, Chennai is thesupplier and CQS Chennai will begiven feedback.



23/34


43. Wrong machining of Flange item no. 01 ofdrg. No. 1-10740-02500(atmospheric reliefdiaphragm) Assembly is done by using longerbolts with spring lock washer since the

modification/ rectification is not possible (SARHWF-004 dated : 3/08/2004 )

Talcher

Site representative providedsketch during meeting and ithas been agreed to take up inRCA committee.

44. SUGGESTION (Talcher)

Spare Lead diaphragm(2 nos per unit) may be

supplied for all the future projects for emergencyrequirements till handing over.

Suggestion has been acceptedby unit.

Sites to contact Haridwar unitfor needful.

45. 1)20 mm gap observed between collar ofscrew and bracket. (2)Beam could not beinserted into support since dimensions ofbeam and support are equal.

Unit action:1) 20mm washers provided. 2) Platewelded on beam at one end was cut andremoved for insertion of beam and replacedlater. (Drg.no.0-12321-25000)

Simhadri

Feedback has been noted byunit and problem has notrecurred.



24/34


46. Radial clearances of LP turbine foundless than design values which necessitatedgrinding/cutting of fins.

Radial and axial offset noticed in the inner

dia of guide blade carriers of LPT 4th,5thand 6th stages

Rihand, Vindhyachal, Mejia and othersites

Repetitive problem. Grinding data hasto be provided to Haridwar unit forRCA committee.

It has been agreed that Sh B Murmu of

PSSR will provide data of Talcher,Simhadri site and Sh O D Sharma ofPSWR will provide data of Rihand &Vindhyachal sites.

47. IPSVs failed to open in Unit-4 due to

suspected problem in the valve blockassembly of the supply rack. After replacingit by other valve block assembly, IPSVsopened

Rihand

Valve block assy has been replaced

from Vindhyachal site. Failed assy ispresently at Haridwar unit.

Unit will inspect and re-test the same.

Procedure/ document will be revisedaccordingly.

48. M42 tapped holes missing in pedestal 3and 4.

4 no holes not available and 3 holes did nothave threads

Rihand

Sub-contracted item. Left overoperations did not get recorded. Scopeclarity between shop & sub-contractoras well as route card entries are beingensured to avoid recurrence.



25/34


49. LP girder holding bolts- all round clearancefound only 1.5 mm instead of 6-7 mm as perdesign

Rihand

It will be taken up in RCAcommittee.

50. Step of 0.02 mm height in the IP rotor frontcoupling face resulting in high value of coupledrunout and swing check of HP front after couplingbolt elongation

Rihand

Feedback will be furtherdeliberated in unit.

51. Some components of overspeed trip releasedevice were found not assembled when receivedfrom works necessitating it to be sent back toworks

Rihand

Assembly is being ensured atworks prior to dispatch.

52. Thermal insulation data sheet for turbineneeds to be revised as it is not suitable for thepresent design . No space for sufficient insulationthickness on shaft seal casings of HPT and IPT

Rihand and other sites

Unit has agreed with sitefeedback and will examine theissue


26/34


53. Thickness of insulating sleeve on test oil pipe inMOP becomes very less after machining to thepresent drawing size which may result in the sleevegetting damaged in short time and part of ittraveling to the overspeed bolts causing mal-operation of overspeed protection as well as failureof insulation between HP rotor and MOP.

Rihand

Site representative gave detailedfeedback on the same.

Increase in diameter nearemergency governor side shallbe reviewed suitably by Engg.

54.Fouling of the stiffener plates of the LP rotorlifting beam with EOT crane main hooknecessitating grinding and cutting of the innerstiffener plate

Rihand

Lifting beams specifications havebeen modified.

55. Fouling of the IP shaft support console on front

side with slings while placing the rotor on stand.Necessitated in cutting the console top in taperfashion ( chamfering of about 50 mm width) toaccommodate the slings

Rihand

Drawing revision will be

considered.


27/34


56. Non availability of shaft lifting device for IProtor rear end. This is essential for removal ofbearing no. 3 when LP rotor is decoupled from IProtor

Rihand and other sites

Unit will examine request fromsites.



28/34

ob e Measures Taken

57. Casing exhaust portion of HPT was foulingwith the front bearing pedestal support blocksprovided for hydraulic jacks on both sides. Thechamfering on the corners of the support blocks

of FB pedestal was increased by 30mm on bothsides. (Drg.no. 0-11601-27000)

Simhadri

Isolated case

Not repeated in subsequentsets

58. Baffle strip is to be provided in the gapbetween TG deck and oil canal. These strips arenot shown in the civil drgs. Baffle strips providedat site. Baffle strips are not in Hardwar scope ofsupply. (Drg.no.0-131-00-81001)

Simhadri

Customer scope

(part of Civil work)

59. Orientation of gland steam inlet pipe is shownon LHS whereas the correct orientation of seal

steam inlet is on the RHS. Assembly of shaft sealcasings will be done keeping inlet steamconnection on RHS. (Drg.no. 1-10710-09000 ; 1-

10711-09000)

Simhadri

Drawing revised.



29/34

Measures Taken

60. Supplied flexible bends had an arm length of1800mm whereas drg. Shows from valve centre toflexible bend with drain header connection as1205mm. Drain pipe line arm length is to be

increased to the required dimension by using extraelbows. (Drg.no. 0-13112-81004)

Simhadri

Document has already beenrevised to have flexible bends

arm length 1200 mm

61. Lube piping scheme for all bearing pedestalsreturn oil lines shows 2 temperature stubs in eachreturn oil line whereas lub oil piping layout showsonly one stub on each return oil line. Site provided 7nos. of stubs and weld on lube oil return lines.(Drg.no. 2-131-00-81101; 0-13111-81003)

Simhadri

Documents has been revised

62. Refer lub oil piping layout.Nb-150 drain line

can't be connected with Nb-200 flange due to non-availability of sufficient space at that location. Sitemade Nb-200 flange with 150mm eccentric openingto suit Nb-150 pipe. (Drg.no. 0-13111-81003,81004; 9-139-36-01000)

Simhadri

Documents has been revised


30/34


63. Control fluid supply line to duplex filter atele.12.7M was fouling with LP Bypass up streamline to LP bypass valve no.01 Control fluid supplyline was cut and re-routed. Pipes Nb-50 & beloware site routed and are to be erected after criticalpiping erection.(0-13155-81006)

Simhadri

Site routed pipes to be erectedonly after erection of criticalpipes

64. Line filters for oil flushing of lub oil system aregetting damaged frequently due to inadequatestrengthening. Site locally manufactured theseline filters with perforated sheet fitted out side themesh .Feed back given to concerned personnel.(Drg.no. 1-11717-18000; 2-11648-27000)

Simhadri

Design has been modified nowusing perforated sheet as persite recommendations.


31/34


65. Groove provided on bearing shell on bottomhalf below the bearing liner is extended andconnected to the groove provided for O-ring on

one of the jacking oil port openings. O-rings mayget damaged. Unit to suggest rectificationprocedure. Under cut area may be built up by

TIG wire ER 70S. (Drg.no. 0-1170327000)

Simhadri

Isolated Case

66. Pressure switch MAV82CP011 is of the range-1 to +1kg/sq cm which will not be able to detectfall in vacuum due to higher hysterisis. Unit tosupply 2 nos. pressure switches of range -5mBar. No such pressure switches available.Change over of exhausters may be done using

discrepancy signals

Simhadri

Not required. Added on requestof NTPC and later withdrawnby NTPC


32/34


67. Heavy leakage was observed from thebottom side of LP/Generator pedestal throughwelding joints between the vertical stiffeners and

base plate on both LHS & RHS. Stiffeners werealso not welded from inside Welding done at siteby Haridwar team

(Drg.no. 0-11803-02000)

Simhadri

Fabrication drawing has beenrevised

68. As per PEM drg, there is no pressure gaugetapping with root valve after the isolation valve ofECW piping to exciter cooler but as per Haridwardrg, pressure points are in PEM scope. Siteprovided the above. (Drg.no. PD-DG-186-179-0101)

Simhadri

During discussions, it wasconveyed that PEM was notprovided this input and it isbeing taken care now.


33/34

Points agreed during discussions

1. Runout & swing check measurement instructions will be made available tosites from Haridwar unit

2. Swing check device of PSWR - Dimensions to be provided to Haridwar unit by

the PSWR for review.3. For MS and HRH strainer welding, supply of two packets of Nicro-82 welding

electrodes per unit will be supplied.

4. All sites to provide package nos. in SARs/ CARs/ MDRs raised.

5. Unit informed that they are not receiving Field Quality Plans from Power sectorRegions for vetting and comments, if any. PS Regional HQs may take noteof this for needful.

6. Product Engg groups at Haridwar will identify list of Corporate Standardsrequiring reference at site. This list will be provided to Power Sector Regions.In turn, PS-Regions/sites will arrange for these standards at the sites.


34/34

THANK YOU