Certification Engineers International Ltd.

C 2501- STRIPPER COLUMN

DESIGN DATA-Design Pressure: 31 kg/cm2

Design Temperature: 170 C max.

Operating Pressure: 26 kg/cm2 max.

Operating Temperature: 135 max.

Corrosion allowance: 6 mm. on CS, 0.0 on Clad or CS + Liner

Hydro test pressure: 46.5 kg/cm2 (Vertical condition)

Total length 42400 mm from TL to TL

ID- 2510 mm.

OBSERVATIONSI) VISUAL INSPECTION a) INTERNAL VISUAL INSPECTION-Shell is good in condition Moderate corrosion on shell wall and tray was observed throughout the column. Weld joints checked visually and no significant abnormalities were noticed. Erosion/ Pitting/ Cracks/ Bulging not observed.

b) EXTERNAL VISUAL INSPECTION-

Painting of column was in progress. Moderate corrosion, pitting & deep depressions was observed on the shell, weld joints and platform (Grating, Brackets, Hand rail, Ladder). Thinning of ladder at edge was observed. Davit was observed non adequate for further use i.e. broken & jammed. Foundation checked visually found in satisfactory condition.

II) NON DESTRUCTIVE TESTING NDT was not carried out from inside as all trays are not removed. Also due to

irregular surface from inside.

III) Thickness Measurement.

Thickness of column checked with D-meter as given below.

ItemMaterialNominal thicknessActual measured thickness% ReductionRemark

Min.Max.

Top dished end (SA 516 GR 60 +SA 240 GR 316L)22+3.5 (Min. 19+3)22.325.2NA

Shell 1 from top(SA 516 GR 60 +SA 240 GR 316L)17+321.322.4NA

Shell 2 from top SA 516 GR 60 +SA 240 GR 316L)17+318.621.410

Shell 3 from top SA 516 GR 60 +SA 240 GR 316L)38+331.642.622.92

Shell 4 from top (Cone)

(SA 516 GR 60 +SA 240 GR 316L)44+3.548.550.3NA

Shell 5 from top

(SA 516 GR 60 +SA 240 GR 316L)38+336.043.812.19

Shell 6 from top(SA 516 GR 60 +SA 240 GR 316L)38+337.043.99.75

Shell 7 from topSA 516 GR 60)4545.946.4NA

Shell 8 from topSA 516 GR 604545.147.3NA

Shell 9 from topSA 516 GR 604544.346.31.5

Shell 10 from top SA 516 GR 604544.045.62.2

Shell 11 from topSA 516 GR 604544.046.32.2

Shell 12 from topSA 516 GR 604543.746.32.8

Shell 13 from topSA 516 GR 604544.746.30.6

Shell 14 from topSA 516 GR 604545.946.8NA

Bottom dished endSA 516 GR 6056 (Min. 48)55.459.0NA

NA- Not Applicable.

Refer attached sketch for more detailsNozzle Details

Nozzle DetailsMaterialSCH / Thickness (mm)Measured Thickness.% ReductionRemark

Min.Max.

TW 2 -1.5 SA 106 GR B9.38.99.34.3

TW 3-1.5 SA 106 GR B9.38.38.710.7

V- 2SA 106 GR BXXS /11.15.65.748.6

D- 3SA 106 GR BXXS/15.2414.614.842.0

M1- 18-17+322.122.4NA

M2- 24-17+321.021.4NA

M3- 24-1815.918.711.6

M4- 24-1817.318.03.8

M5- 24-1817.018.15.5

M6- 24-1816.117.610.5

RL- 14SA 106 GR B1818.418.7NA

RT- 4SA 106 GR BSCH160 / 13.512.412.98.1

T- 8SA 106 GR BSCH 160 / 237.98.065.6

R- 3SA 106 GR BXXS / 15.247.88.048.8

F- 6SA 106 GR BSCH 160 / 18.36.36.965.5

VR- 12-1818.118.3NA

LG1- 2SA 106 GR BXXS / 11.17.79.630.6

LG2- 2SA 106 GR BXXS / 11.111.211.4NA

LA1- 2SA 106 GR BXXS / 11.16.910.037.9

LA2- 2SA 106 GR BXXS / 11.111.211.4NA

TC- 1.5SA 106 GR B9.37.99.315.0

TI2- 1.5SA 106 GR B9.39.39.6NA

TI3- 1.5SA 106 GR B9.39.19.42.1

DP2- 1.5SA 106 GR B9.37.79.017.2

DP3- 1.5SA 106 GR B9.37.58.019.3

PA1- 1.5 SA 106 GR B9.37.79.817.2

PA2-1.5 SA 106 GR B9.37.09.824.7

UC- 2SA 106 GR BXXS / 11.18.99.019.8

TW1-1.5SA 106 GR B9.33.74.060.2

TI1- 1.5SA 106 GR B9.32.34.575.2Heavy corrosion & hole

DP1- 1.5SA 106 GR B9.32.75.770.9

IV) HYDROSTATIC TEST Hydrostatic test was not carried out by ONGC.

V) RECOMENDATION-

Evaluating the thickness measurement for shell, column shell is ___________found to be adequate for further service. All Nozzles adequacy for further service to be checked. DFT of paint should be checked and should be within the acceptable range.

Platform, ladder, grating, handrail, require strengthening or wherever. strengthening is not possible to be replaced, also to be painted to protect from further corrosion.Note- This is provisional inspection report, final report will be submitted later.