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QUALITY

CHECKS DURINGO/H

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Boiler Pass 1&2

Ducts

Rotary parts

ESP

Turbine auxilaries

Generator

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ROLE OF QUALITY ASSURANCE DEPT. AT

SITE:

TO PREPARE QUALITY PLAN BEFORE OVERHAUL.

TO PREPARE QA CHECK LISTS.

TO INVOLVE IN CRITICAL CHECKS DURING OVERHAUL. TO INVOLVE IN DAY TO DAY MAINTENANCE.

TO CARRYOUT NON DESTRUCTIVE TESTING.

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Boiler pass 1 & 2

(Tube Failure Mechanisms)

Erosion

Corrosion

Mechanical wear

Material mix-up

Weld failures i.e Dissimilar & attachment weldfailures

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Preventive measures during O/H

100% visual inspection in all the identified areas

Deploying IBR qualified welders & use of

approved electrodes Extensive Tube Thickness survey

NDT of welds( DPT, RT, UT &MPI)

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QA methodology in different

areas

Goose neck region:DPT, Visualinspection and TTS

RH girdling loops:Visual inspection for

dents and distortion of binding loops

Economisers & LTSH:TTS for top, bottom, extreme coils both

Sides 1 to 5 tubes and visual inspectionfor alignment and erosion.

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LTSH bifurcation tubes:Visual inspection for refractory damage and erosion & TTS

RH : Visual inspection for overheating ,cleat rubbing (half reheater)and

TTS & DPT

Header stub joints: Visual inspection and DPTScreen tubes:

TTS and visual inspection

Raiser tubes:

MPI / RT of bends and weldments

QA methodology in different

areas

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FANS AND ESP

II PAFan, FD Fan:

Blade alignment and clearances, motor & fanalignment and blades DPT

III ID Fan:1. Bearing surface Visual & DPT

2. Shaft visual inspection for pitting3. Welding joints and shaft- MPI&DPT

ESP:Erosion of emitting electrodes, hammer

Rings, bending of shock bar and cracking ofsuspension frame hooks of collecting electrodes.

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24 May 2012 PMI Revision 00 13PENETRANT APPLICATION READY FOR INSPECTION

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TURBINE

Main turbine (HP,IP and LP) checks

NDT checks on turbine and auxilaries

Generator checks

NDT on generator

Other checks in different areas

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Radial alignment

Axial alignment

Clearances measurement

Coupling run out

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Visual inspection

Blue matching of valves

DPT & MPI of components

UT of bearings

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Turbine blades, De aerator perforated sheets, rotoralumina blast cleaning

Shafts of CEP,BFP and vacuum pumps

HRH & MS strainers

Valves seating area

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Line contact to be ensured

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Shafts of CEP,BFP and Vacuum pumps MS & HRH strainer line weld joints, control fluid

oil line weld joints, impulse line weld joints

TDBFP gear coupling , bearings babbit metalarea.

Stop valves & control valves components

MPI of rotor & blades

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UT of bearings

To assess the de-bonding of babbitting

Reference Standard: ASTM A 435 Acceptance norms: No multiple backwall echos

UNIT 4 BrgThrust pads-36 Nos

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After rotor threading out-rotor N2 pressure test(leakage - Not morethan 0.5

kg/sg.cm for 6 hrs)

IR value of rotor

RSO test of rotor( sinusoidal wave form)

Winding resistance

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Stator

Visual inspection of stator

IR value of stator

Wedge tightness , ELCID test and tan

Winding resistance

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DPT of compressor blades

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Other areas

DPT of expansion bellows

DPT of HP heaters parting plane welds

Condenser cleaning

Deaerator visual inspection

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