Draft Report Tank

DRAFT EVALUATION REPORT

RECONSTRUCTION OF TANK T-53 AT

KEAMARI TERMINAL

PROJECT : RECONSTRUCTION OF TANK T-53 AT KEAMARI TERMINAL CLIENT : PAKISTAN REFINERY LIMITED LIMITED JOB NO. : 0800

CONSULTANTS : PETROCHEM ENGINEERING SERVICES

PAKISTAN REFINERY LIMITED

Doc. No. : ER-51 Sheet 2 of 7

Disclaimer

This report has been prepared on behalf of and for the exclusive use of Pakistan Refinery Ltd. (PRL), and is subject to and issued in accordance with the agreement between Petrochem Engineering Services and PRL. Petrochem Engineering Services accept no liability or responsibility whatsoever for it in respect of any use of or reliance upon this report by any third party. Copying this report without the permission of Petrochem Engineering Services is not permitted.

CONTROLLED COPY HOLDERS

NO. NAME COMPANY NO. NAME COMPANY

1 Nadeem Akhter PRL 5

2 Imran PRL 6

3 7

4 8

REV DESCRIPTION ORIG REVIEW PES

APPROVAL DATE CLIENT

APPROVAL DATE

A Issued for internal review

Faizan

Umair

Shoaib Apr. 11, 12

B Issued for Client Comments.

Faizan

N/A

N/A

Apr. 12, 12


C O N T E N T S

SECTION D E S C R I P T I O N PAGE NO. 1.0 INTRODUCTION 04 2.0 RECOMMENDATIONS 04 3.0 CODES AND STANDARDS 06 4.0 TOLERANCES 06


1.0 INTRODUCTION

Pakistan Refinery Limited (PRL) is converting existing storage tank T-53 from Fixed Roof to External Floating Roof for the storage of crude oil at its Keamari Terminal. As per existing condition, fixed roof and top 4 courses have been removed. Bottom plate is disengaged from annular plate. It was observed at site that tank plumbness at fourth course is deviated from allowable limits as mentioned in API 653. Furthermore settlement was found at portion of Earthen foundation of tank.

PRL hired SGS for the inspection of tank T-53 as per API 653. Report has been submitted by SGS which is the basis for further evaluatoion of tank conditions. The Plumbness, Shell bulging and Roundness reports provided by SGS are thoroughly viewed and calculated by PES. On the basis of calculation results and standards, followings are our observation and recommendations.

2.0 RECOMMENDATIONS 2.1 Tank settlement at one side is minor issue. The major observation is as under:

i) Plate squarness was not maintained at the time of construction of Tank ii) Welding sequence was not followed by the Contractor and therefore overheat

regions were developed on tank shell which created bulging effect. 2.2 Plumbness values found in Course 1 & 2 (from Bottom to Top) are in allowable limits

of API 653 (See Annexure-1) 2.3 Plumbness in Course Number 3 & 4 (from Bottom to Top) is more than allowable

range as per API 653 i.e. 1/100 of tank height which is not acceptable. Courses 3 & 4, therefore cannot be used and shall be removed. (See Annexure-1)

2.4 For foundation settlement, it is recommended that remaining two courses shall be

lifted through jacks and repair the area (See Annexure-2) 2.5 Plumbness found in courses 1 & 2 is in allowable limits but there are some portions

in course no. 2 where repair work is required for the proper erection of upper


courses. It is recommended to cut and re-roll the plates of course no. 2 at 45o, 180o, 165o, 285o, 300o & 330o to minimize the bulging / deformations.

2.6 After repair of course no. 2, it is necessary to check again the Roudness and

Plumbness of top course 2. There may be a possibility to adjust some plate dimensions of course no. 3 as per inspection data of course no. 2 after its erection.

2.7 Before cutting courses 3 and 4, following steps shall be done for the repair of course

no. 2.

i) Channel of 6 x 3 x 12mm thick shall be weld to the top of course 2 before cutting of course 3 & 4

ii) Curvature plates of size 9 shall be welded to the shell iii) No direct hammering to the plates shall be carried out to remove the

deformations. Hammering, if carried out, shall be on an intermediate block part placed to avoid direct impact on plates.

iv) Wages shall be used in the gaps to remove deformation of shell plates. v) After being rolled, the plates shall be checked with steel templates having a

radius equal to rolled inside radius. For a 2 m. long template, the clearance between template and plate surface shall not be greater than 3.2 mm

vi) Rolling radius of plates for tanks of 8 m. diameter and larger, plates upto 25 mm. thick are recommended to be rolled at 1.25 x tank radius. For plates thicker than 25 mm. rolling radius shall be equal to tank radius.

vii) Over rolling of plates is not allowed. viii) No heating is allowed to straighten the plates deformed by shrinkage.

Eventual straightening shall be done by cutting the respective welding seams and rewelding them on the basis of an approved procedure.

ix) Plates of second course shall then be mounted according to the orientation. After being adjusted, aligned and tack welded, vertical seams shall be welded.

x) For finished horizontal butt welds the upper plate shall not go beyond the lower plate surface in any point by more than 20% of upper plate thickness, but not greater than 1/8" (3.17 mm).

xi) Horizontal welding shall then be performed between the first two courses. xii) Welding shall be performed with shielded metal arc, shielded arc, or

submerged arc procedure using suitable equipment.


xiii) Each metal layer of a welding seam shall be cleaned free of slag and other foreign matters before applying the next layer.

xiv) The edges of all welds shall merge into plate surface without forming a sharp angle.

3.0 CODES AND STANDARDS

All engineering, repairing, technical documentation shall comply with the requirements of this report and the following codes/standards referred herein:

API Standard 650 API Standard 653 ASME Section IX ASTM specification for carbon steel plates.

4.0 DIMENSIONAL TOLERANCES

As per API 653(Tank Inspection, Repair, Alteration & Reconstruction) 4.1 Plumbness

The Maximum out of plumbness of the top of the shell relative to the bottom of the shell shall not exceed 1/100 of the total tank height.

4.2 Roundness

Radial measurement at 300 mm above lap weld between shell and bottom shall not exceed the following tolerance:

Tank Diameter Radius Tolerance 0 to 12.2m exclusive + 12.7mm 12.2 to 45.7m exclusive + 19.0mm 45.7 to 76.2m exclusive + 25.0mm 76.2m and over + 32.0mm


4.3 Peaking

With a horizontal sweep board 36-in. long, peaking shall not exceed . The sweep board shall be made to the true outside radius of the tank.

4.4 Banding

With a vertical sweep board 36 long, banding shall not exceed .

ANNEXURE1Doc.No: 0800TR53001Date: 11/4/2012

Prepby: Faizan

PAKISTANREFINERYLIMITED

Tank53KeamariTerminalCalculationsforTankRoundness/Plumbness

OptionICoursenos.1to4

SGSAnnexure1

AllowableAPI653

Remarks

Roundnessat1ftabovethebottom

cornerweld(Approx.)

Location Course-1 Course-4 PlumbnessCalculated

Roundnessat1stcourseTop/Bottom(SGS)

A B A B

0o 18.304014 18.299377 18.277084 18.265974 0.038 0.051 0.072 0.001 4

45o 18.276373 18.297309 18.304203 18.305685 -0.029 0.021 0.072 0.017 9

90o 18.267085 18.288496 18.309717 18.316336 -0.049 0.047 0.072 0.028 6

135o 18.266647 18.275004 18.261834 18.255099 0.012 0.015 0.072 0.003 6.5

180o 18.187036 18.211426 18.264316 18.276166 -0.089 0.101 0.072 0.035 13

225o 18.3475 18.32917 18.288437 18.269143 0.078 0.091 0.072 0.023 0

270o 18.197815 18.222318 18.270240 18.278567 -0.081 0.077 0.072 0.025 0

AllowablePlumbness:0.072asperAPI653

AllowableRoundness:11/4''(32mm)asperAPI650/653

ANNEXURE1 Doc.No: 0800TR53002

Date: 11/4/2012

Prepby: Faizan

Location PlumbnessCalculated

SGSAnnexure1

AllowableAPI653

Roundnessat1stcourseTop/Bottom(SGS)

Roundnessat1ftabovethebottom

cornerweld(Approx.)Remarks

A B A B

PAKISTANREFINERYLIMITED

Tank53KeamariTerminal

CalculationsforTankRoundness/Plumbness

Course-1 Course-2

OptionIICourseNos.I&2

A B A B

0o 18.304014 18.299377 18.31043 18.294682 -0.009 -0.014 0.072 0.001 4

45o 18.276373 18.297309 18.301015 18.31395 0.038 0.036 0.072 0.017 9

90o 18.267085 18.288496 18.298866 18.297964 0.031 0.028 0.072 0.028 6

135o 18.266647 18.275004 18.277808 18.274639 0.008 0.005 0.072 0.003 6.5

180o 18.187036 18.211426 18.217577 18.23186 0.045 0.058 0.072 0.035 13

225o 18.3475 18.32917 18.326758 18.319235 -0.028 -0.031 0.072 0.023 0

270o 18.197815 18.222318 18.227533 18.239172 0.041 0.044 0.072 0.025 0

AllowablePlumbness:0.072asperAPI653

AllowableRoundness:11/4''(32mm)asperAPI650/653

ANNEXURE: B

For repairing the damage area of tank foundation it is needed to lift the tank up to 1.5ft height. The procedure recommended for lifting the tank (1st and 2nd course) is through hydraulic jacks. Various steps of lifting the tank through hydraulic jacks are given below:

1. Disconnect all tank attachment and piping connection also removes the annular plates from tanks shell. Ensure that top course i.e. course no:2 shall be properly secured with circumferential tack welding of channel 6x3.

2. Mark the location and install the jacking brackets on circumference of shell. 3. Install the plates in tank berm to properly distribute the jack reaction on tank

foundation through these plates. 4. Install the 20 nos jacks on the plates against the corresponding brackets

(capacity of each jack required is 6 tons). Lift the tank with help of jacks up to 1.5ft height.

5. Install the tripod stand. 6. From proper topographic survey, locate the damage area of foundation. Scarify

the bitumen layer with sand from that portion up to 300mm. 7. Refill it with coarse sand with maximum size not exceeding 10mm and fall within

following grading limits.

8. Qualified personnels and approved laboratory facilities shall be provided to modified AASHTO 95% dry density and determination of moisture content of fill material to control the compaction.

9. Again place the bitumen layer maintaining proper slope as mentioned in project drawing.

BS Standard Sieve % Passing (By Weight)

(3/8 ") 100

(3/16 ") 90 - 100

No. 7 60 - 95 No. 14 30 - 70 No. 25 15 - 35 No. 52 10 - 25 No. 100 5 - 15 No. 200 0 - 10

CALCULATIONS

DATADiaofTank = 120 ftHeightofTank = 48 ft

CALCULATION

First CourseThikness = 19 mmPerimeter = 114.683 mHeight = 1.8 mWeight = 30.78895 Tons

Second CourseThikness = 16 mmPerimeter = 114.683 mHeight = 1.8 mWeight = 25.92753 Tons

Angle Iron= C6"X3"

Weight/Length= 18 kg/mWeight/Length 18 kg/mLength = 115 mWeight = 2.07 Tons

Total Weight = 58.78648 TONSOR = 60 TONS

LIFTING JACKSCapacityof1jack = 6 TonsNumberOfJacks = 20 Nos

PLATES UNDER JACKS

AssumeAreaOfPlate= 1mX1mWeightFromJack = 6 tonsLoad/Area = 6 tons/m OR 0.557 TsfBearingCapacityofsoil 1 ton/ft > 0.557 OKThiknessOfPlate = 20 mm

BRACING (8"X4"X1)

3Tons

ISECTION SHELL(8"X4"X1)

WELD

3FTJACK

PLATE

Moment = 9tonft OR 19.836 Kft

Sx = 9X2.204X12 = 11in0.6X36

USE 8"X4"X1" Sx = 12.6in OK

Documents

Draft Report Tank