F.sq-wI.008 Procedure for Inspection of Existing Storage Tank

8/19/2019 F.sq-wI.008 Procedure for Inspection of Existing Storage Tank

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PROSEDUR PEMERIKSAAN TEKNIS ULANGTANGKI PENIMBUN

DOCUMENT NUMBER REV DATE SHEET

F.SQ-P.008 0 11 Agustus 2011 1 of 17

F.SQ-WI.008 Procedure For Inspection of Exist ing Storage Tank.doc

PROCEDURE AUTHORIZATION

This procedure have been generated and implementedto identify the control that shall be applied by members ofstaff in the department when carrying out their duties

Department Authorization

Signed:

Date:

This confirms that this procedure has been approved forofficial issue and that members of staff shall complete thetasks assigned in accordance with the mechanismsdefined herein

Corporate Authorization(Company Director)

Signed:

Date:

The procedure forms part of a formal system within thecompany which ensures that this document is handled ina controlled manner in accordance with documentedprocedures.

This procedure will be subject to audit as part of thecompany policy towards quality

Quality Authorization(Quality Management Rep' s)

Signed:

Date:

PROCEDURE REVISION

Rev. Date Section Outline of Changed Authorization

0 11 Agustus 2011 First Issue

1

2

3

4

STATEMENT OF CONFIDENTIALITY


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TABLE OF CONTENT

Page

1.0 PURPOSE 4

2.0 SCOPE 4

3.0 DEFINITIONS 4

4.0 REFERENCES 5

5.0 RESPONSIBILITIES 5

6.0 PROCEDURES OF IN-SERVICE STORAGE TANK INSPECTION 5

6.1 DOCUMENTATION REVIEW 5

6.1.1 Previous Certificate 6

6.1.2 Tank Data 6

6.1.3 Manufacturing Data Record 6

6.1.4 Usage and Maintenance History 6

6.1.5 Reparation, Alteration and Reconstruction (if any) 7

6.2 PHYSICAL INSPECTION 7

6.2.1 In-Service Inspection 8

6.2.1.1 Roof Tank 8

6.2.1.2 Shell Tank 8

6.2.1.3 Tank Foundation 86.2.1.4 Fire Hazardous and Corrosion Protection 8

6.2.1.5 Tank Safety Equipment 8

6.2.1.6 Reporting 8

6.2.2 Out Service Inspection 9

6.2.2.1 Roof Tank and Structural member 9

6.2.2.2 Shell Tank 9

6.2.2.3 Tank Bottom 9

6.2.2.4 Tank Foundation 10

6.2.2.5 Fire Hazardous and Corrosion Protection 11


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6.2.2.6 Corrosion Control Equipment 11

6.2.2.7 Tank Safety Equipment 11

6.2.2.8 Recording 11

6.3 ACCEPTANCE CRITERIA 12

6.3.1 Document Review 12

6.3.2 Tank Component Inspection 12

6.3.3 Roof 12

6.3.4 Shell 12

6.3.5 Bottom 13

6.3.6 Foundation 14

6.3.6.1 Differential Settlement 14

6.3.6.2 Internal Bottom Distortion 15

6.3.6.3 Edge Settlement 15

6.3.7 Corrosion Protection System 15

6.3.8 Venting System 16

6.3.9 Fire Hazardous Protection System 16

6.3.10 Attachment 16

6.3.11 Appurtenance 16

6.3.12 Bund Wall 16

6.4 REPORTING, RECORDS AND DOCUMENTATION SYSTEM 16

6.4.1 INSPECTION LOG BOOK 17

6.4.2 INSPECTION REPORT 17

6.4.3 SURVEILLANCE REPORT 17

6.4.4 EXTERNAL DOCUMENT 17

7.0 ATTACHMENT 17


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1.0 PURPOSE

a. The purpose of this document is to ensure that the in-service storage tank isin safe condition.

b. Provide guideline for surveyor to perform reviewing, inspection, verifyingand testing of existing storage tank comply with requirements.

2.0 SCOPE

a. This procedure shall be applied for Storage tanks, that have been placedand have been inspected by an authorized inspection agency.

b. The procedure covers the minimum requirement International Code andStandard, or Owner/User inspection procedure.

c. This is Company approved procedure and shall be adhered to at all timeexcept where Owner/User documents species other requirement.

3.0 DEFINITIONS

a. Surveyor or Engineer - The person that takes any inspection of

storage tank under employed company whohas the Storage tank Inspector Certificate

b. Company - Andre

c. Owner/user - The organization legally responsible for theoperation, maintenance and safety, includingthe repair, modification or replacement ofitems in the plant of storage tank

d. Inspection - The work necessary to check the tank for

defect such as corrosion, cracking or otherdamage to certify the tank as safe foroperation or in need of repair.

e. In service inspection - On-line inspection, an external inspectionbeing performed when the storage tank isused.

f. Out-of-service inspection - Off-line inspection, an internal inspectionwhen the storage tank is not used


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4.0 REFERENCES

The following minimum reference for Storage tank construction, but not limited to:

API RP 575, Inspection of Atmosferic and Low – Pressure storage Tanks.

API Std 653, Tank Inspection, Repair, Alteration and Recontruction.

API Std 651, Cathodic Protection of aboveground Petroleum Storage Tanks.

API Std 652, Lining of Aboveground Petroleum Storage Tank Bottom.

API Std 650, Welded Steel Tank for Oil Storage.

API Std 2000, Venting Atmospheric and Low-Pressure Storage Tanks.

API Std 2015, Safe Entry and Cleaning of Petroleum Storage Tanks.

EEMUA 159, User’s Guide to The Maintenance and Inspection of Above-groundVertical Cylindrical Steel Storage Tank .

EEMUA 183, Guide for The Prevention of Bottom Leakage from Vertical,Cylindrical, Steel Storage Tank .

NFPA 30, Flammable and Combustible Liquids Code.

NFPA 78, Lightning Protection Code.

Keputusan Direktorat Jenderal Minyak dan Gas Bumi Nomor :

84.K/38/DJM/1998.Keputusan Direktorat Jenderal Minyak dan Gas Bumi Nomor : 39.K/38/DJM/2002.

5.0 RESPONSIBILITIES

a. The Company Management shall be responsible for ensuring that thenecessary resources are made available for the requirements of thisprocedure to be carried out in the safe manner.

b. Line Management shall be responsible for ensuring that the requirements ofthis procedure are fully implemented at all times.

c. All employee involved in the implementation of this procedure shall beresponsible for adherence to the requirements stated within.

6.0 PROCEDURES OF EXISTING STORAGE TANK INSPECTION

6.1. DOCUMENTATION REVIEW

Before and during inspection performing the surveyor shall be review thefollowing documentation : company work instruction no: F.SQ-WI.008.1Rev. 0 Work Instruction for Storage tank In-Service Recertification,


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company work instruction no: F.SQ-WI.008.2 Rev. 0 Work Instruction for

Storage Tank Out of Service Recertification, company standard form no.F.SQ-F.008.1 Rev. 0 In-Service Storage tank Inspection and VerificationCheck List and company standard form no. F.SQ-F.008.2 Rev. 0 Out ofService Storage tank Inspection and Verification Check List, but not limitedto :

6.1.1 Previous certificateQuality control system of the owner inspection / operatorQuality control system review covers, but shall not limited to: Tank maintenance plan Working procedure

Line of responsibility Reporting procedure Personnel competence Calibration scheme

6.1.2 Tank DataStandard require the maintaining of complete file recorded dividedinto three records by the owner / tank operator, which are: Manufacturing Data Record Maintenance history / inspection Reparation history / alteration

6.1.3 Manufacturing Data RecordManufacturing Data Record shall be reviewed, but not limited to: Quality control of manufacturing data record Used standard Name plate Material specification Drawings; Tank specification Design calculation Welding Procedure Specification; Procedure Qualification Records; Welder Qualification; Nondestructive Test; Hydrostatic test with survey settlement; Final Construction report All analysis result and material test

6.1.4 Usage and Maintenance HistoryUsage and maintenance history consist of written note about tankusage (product changing and the change of usage recorded alongwith the condition such as temperature and product pressure) at alltimes along with the action taken on the maintenance of the tank.


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Usage and maintenance history shall equip with inspection history

that inserted all action taken into measurement, condition of everypart being inspected, and a record upon every inspection and test.Inspection history covers inspection reports.

The primary obser vation for “safe operation” in the storage tankinspection is:

Corrosion rate level Remaining life

Corrosion rate and remaining life can be calculated using the

following formula:

Remaining life = t actual – t minimum

Corrosion rate

Remain life = the left over years of tank component, within year;

t actual = measured thickness during inspection at the locationor used component to determine the allowableminimum thickness, in or mm;

t minimum = minimum thickness allowable at the location or certaincomponent, in or mm

Corrosion rate = t previous – t actual Period between t previous and t actual

Corrosion rate is stated in per year or mm per year.

t previous = thickness at the same location with t actual measured atthe previous inspection, with in or mm

6.1.5 REPARATION, ALTERATION AND RECONSTRUCTION (IF ANY)Reparation history / alteration shall insert every data gathered from atank covers its construction, particularly those related withreparation, alteration. This record shall insert coating performancesand used lining.This reparation history /alteration shall include location, scope, andused standard. This document shall be reviewed to obtain goodengineering judgment.

6.2 PHYSICAL INSPECTION Visual and inspection result verification (measurement, calculation andrecommendation) shall be performed by authorized inspection agency.


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Visual inspection shall be carried out with the F.SQ-F.008.1 Rev. 0 and F.SQ-

F.008.2 Rev. 0 guidance.

There are two forms of physical inspection, which are” 6.2.1 In-Service Inspection

This inspection is done during the storage tank used. The inspectionconsists of:

6.2.1.1 Roof tank

Visual inspection at the entire roof part.

Verify result of wall thickness measurement.

Verify result of Non Destructive Test (NDT).6.2.1.2 Shell Tank

Inspection performed including nozzle, drain, manhole, windgirder and other part at shell.

Visual inspection the entire shell part.

Verify result of wall thickness measurement.

Verify result of Non Destructive Test (NDT).

Verify result of minimum thickness calculation.6.2.1.3 Tank Foundation

Visual inspection the entire foundation part.

Verify result of settlement measurement.

Verify bund area (surround the foundation)

Foundation condition shall be evaluated comply withrequirements from standard API-653.

6.2.1.4 Fire Hazardous and Corrosion Protection

Verify fire protection equipment.

Verify result of corrosion control equipment measurement,such as coating and cathode protection. The voltagebetween tank and the ground, the maximal voltage is -0,85Volt. The survey shall comply with API RP 651.

6.2.1.5 Tank Safety Equipment

Pressure vacuum vents and breather valves shall beinspected visual. Ensure, whether there is a periodicallyfunctional test from the owner inspection record.

6.2.1.6 ReportingMinimum documents shall be arranged in the following:1. Certificate of Inspection2. Migas Appointment Letter3. Previous certificate issued by MIGAS4. Visual Inspection Report5. Calculation Sheet6. Construction Data Report7. Copy of the Name Plate Rubbing

8. Inspection/Maintenance Records9. As built drawing


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scan or digital ultrasonic thickness shall be used for the

detection area. Tank bottom shall be checked from anydamage caused by the tank settlement. (Ref.API-653 App. B)

Evaluate the bottom tank thickness by using magnetic fluxleakage, corrosion scanning& ultrasonic test. The minimumthickness for tank bottom at the upcoming inspection shall be0,05” – 0,10” (ref.Table 4-1 API 653)

Tank Bottom measurement approximation shall use one ofthe following methods:

Deterministic method: by calculating internal and externalpitting (Ref.API-653 Par. 2.4.7.1)

Probabilistic Method: using statistic approach from thethickness measurement.

Tank bottom minimum thickness at the critical zone – or atthe annular plate ring or area 12” from the shell inside thetank or area 12” from the shell inside the tank or at theannular plate ring is the smallest from half of the platethickness (without any corrosion allowance) or 50% fromthe bottom minimum shell thickness but not least than0,1”), The projection thickness of the shell weld – bottom

plate is at the minimum of 3/8. Minimum thickness of annular plate is similar to the bottom

plate critical zone.

6.2.2.4 Tank Foundation

Perform visual inspection at the entire foundation part.

Foundation can be made from underpinning, rocks, ringwalls or bolster. This bolster shall be inspected againstreform possibility and uncommon settlement. Settlementmeasurement result verification, and bud area (areaaround the foundation). Foundation condition shall be

evaluated comply to standard requirement API-653.

If the foundation is specified as horizontal as the toleranceshall be:a. If concrete ring wall is given under the shell:

The top of the ring wall shall be at the same level atmaximum ⅛ for every 30 ft peripheral and ¼ from totalperipheral measured by average height.

b. If concrete ring wall is not given under the shell:⅛ for every 10 ft from peripheral and ½”from totalperipheral, measured by the average height.


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If the foundation deviation is specified, elevation difference

around the peripheral shall be calculated from the highestpoint. Actual difference around the peripheral shall bedetermined by the specified height point. Actual heightdifference shall not exceed from the tolerance below:

a. If concrete ring wall is given, ⅛” for every 30 ft fromperiphery height and ¼ from total periphery.

b. If there is no concrete ring wall, 1/8” for every 10 ft of theperiphery height and ½” for total height of periphery.

6.2.2.5 Fire Hazardous and Corrosion Protection

Fire protection equipment such as flame arrester, earthenand concrete dikes shall be inspected visually whileconfrontation to the periodically inspection record of theowner. For fire safety equipment such as light fireextinguisher, other than visual inspection also watch thefunctional test record which supposed to be performedperiodically.

6.2.2.6 Corrosion control equipment, such as coating and cathodeprotection shall be inspected. Ensure that the coating is intact

other part that not painted shall be protected by systemcathode protection. Do a different voltage measurementbetween the tank and the ground. The maximal protectiondifference is 0,850 Volt.

6.2.2.7 Tank Safety EquipmentPressure vacuum vents and breather valves shall beinspected visually. Ensure, whether the functional test existperiodically from the owner inspection record.

6.2.2.8 Recording

Similar to new storage tank certification, the minimal of thedocuments is as follow:

Certification of Inspection

MIGAS Appointment Letter

The authorization license of previous usage issued byDitjen MIGAS

Visual Inspection Report

Calculation Sheet

Construction Data Report

Copy of Name Plate Rubbing

Inspection/Maintenance Records

As Built Drawing


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6.3 ACCEPTANCE CRITERIA

Certification shall be handed out whenever there is no non-conformancereport found or has been taken care in adequate manner.

6.3.1 Document review Acceptance criteria from the document review are completeness,validity, document rightness, along with adequate evidence.First of all, inspection report from the Authorized inspection agencyshall comply with the date completeness criteria, and shall fulfill the

technical criteria comply with code /standard as strand in the followingsub chapters.

6.3.2 Tank component inspectionPhysical inspection shall appointed consistency related with the resultof document review.

6.3.3 Roof API Std 653 4.2 – Any corrosion with average thickness less than 0.09in occur within 100 in2 area shall be replaced.

Structural part from the tank foundation (column, bottom, rafter, andblock) shall free from any distortion, corrosion, and mechanicaldamage. A leak shall not be found at the float roof tank. The seal system, anti-rotation equipment, rain drainage system, and ventilation system shallwork properly.

6.3.4 ShellEvery shell course shall be measured by the method of actualthickness comply with API Std 653 4.3.1.Crack shall not permitted from the shell to the bottom

Generally, the minimum thickness for every course is determined bycalculating this formula (Only for tank with diameter less than 200 ft),add to the thickness to other pressure condition comply with API Std653 4.3.3.5

t min = 2,6 ( H – I ) D.G

S.Et min = minimum thickness, in;D = nominal diameter, ft;H = the height level of L for the worst corrosion area in every

course up to the liquid maximum level, ft;

G = the mass of product;S = Maximum allowable stress in psi, for the first course and

the second course at minimal (0.80-Y or 0,429T) shall be


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used and min (0.88Y or 0.472T) shall be used for other

course;Y = Specific minimum yield strength of plate, use 30000 psi if

not known.

6.3.5 BottomLeakage shall not be allowed at the tank bottom (either bottom plateor annular plate, if available). API Std 653 4.4.7.3 – minimum thickness of bottom plate shall not beless than the bottom plate thickness as listed in table 6-1 API Std653, as rewritten below:

Table 1 – Minimum thickness of bottom plate (API Standard 653table 6-1)

Minimum thickness at thebottom plate for the followinginspection (in)

Tank Bottom / foundation design

0.10Bottom design / tank foundationwithout any detection andreservoir upon bottom leaking

0.05

Bottom design / tank foundation

meant to detect and givesreservoir upon bottom leaking

0.05

The existence of reinforced lining(by using fiberglass or glassflake), thickness > 0.05 in complywith API RP 652.

Tank designed with annular plate, other than earthquake pressure,shall have the minimum thickness as given from Table 2 and Table 3below (depend on the mass of the storage product) plus corrosionallowance.

Note: Specified thickness in table 2 and table 3 is meant to givefoundation with flat buffer as width as annular plate. The thicknessshell plate is the bottom plate thickness at the construction.Table 2 – Annular Plate Thickness (in) for Product Mass < 1.0 [APIstd 653 Table 4-4]

First course of shellthickness (in)

The first shell course strength (psi)


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Table 3 – Annular Plate Thickness (in) for Product Mass ≥ 1.0 [APIstd 653 Table 3-1]

First course of shellthickness (in)

The first shell course hydrostatic teststrength (psi)

< 7.000


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6.3.6.2 Internal Bottom DistortionInternal bottom distortion can form shape into concave orprotrusion at the tank bottom, and the depth/height shall notexceed BB. The following R measurement method in thisformula complies with picture B-8 API Std 653.

BB = 0,37. RBB = Protrusion height or the maximum depth of concave,

in;R = circular radius as shown in the concave or protrusion,

in ft;

6.3.6.3 Edge SettlementThe edge settlement measurement method is described inthe Picture B-5 API Std 653.Maximum edge settlement limitation is shown is API Std 653picture B-10 and B-11., as inserted in the next page aspicture 1 and picture 2.Permitted maximum settlement side for area withoverlapping welding similar or parallel to shell (Figure B-10 API Std 653).

Permitted maximum settlement side for area withoverlapping welding similar or perpendicular to shell (FigureB-11 API STD 653)

6.3.7 Corrosion Protection System API RP 575 7.2.7 – In the corrosion protection system such ascoating, particularly the one that lies at the submerged product(internal tank) shall not find any blemish reach to the other side of themetal such as blistering, holiday. API RP 651 – In the corrosion protection system such as cathodeprotection by using measurement method as API RP 651 8.3, at

minimal shall fulfill these criteria:Negative potential shall value at least 850 mV with the attachcathode protection current. This potential shall be measured againstreference saturated copper / copper sulfate (CSE) that connect withthe electrolyte. Strength decreasing other than the one lay along thebottom edge of the tank-to-electrolyte shall be calculated for validinterpretation from this strength measurement.Negative strength shall be polarized at lest 850 mV against CSE. At least 100 mV measured cathode polarized between the bottommetallic surface of the tank and the stable reference electrode thatconnected with electrolyte.

6.3.8 Venting system


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The entire appurtenances on the roof, as if flame arrester, P/V valve,

breather valve shall be calibrated, and packing at nozzle with propercondition, every dynamic part and shall not experience any significantcorrosion.Strain part or grid from the flame arrester shall be cleaned and freefrom corrosion.Venting equipment capacity complies with tank specification asrequired in API Std 2000.

6.3.9 Fire Hazardous Protection SystemThe fire hazardous protection system consists of the fire hazardousequipment and fire extinguisher equipment.

API RP 570 7.2.6 - Every grounding system shall be well connected,and the total resistance from tank to the ground shall not exceed 25ohm. Fire extinguisher equipment such as lightning rod, grounding,flame arrester and fire extinguisher equipment such as foam pipe,foam chamber, adherences, spray nozzle, are properly workedwithout any leaking or corrosion.

6.3.10 Attachments API RP 570 7.2 – At the ladder, platform, stiffeners, angle, stairs,anchor shall not be found any mechanical damage caused by

corrosion or because other source that might endanger tankoperation. If tank is equipped with insulation, tank shall not have anyopening insulation that might potentially become water reservoir.

6.3.11 AppurtenancesComponents such as man way, nozzle, piping manifold, samplestation, heater, mixer, access way, ladder, stairway, and platformshall not allow having mechanical damage caused by corrosion orother cause that might endanger tank operation.

6.3.12 Bund Wall

Material used to form bund wall shall consist of water proof material.Bund wall shall capable to reservoir the biggest liquid volume thatmight eject from the biggest tank within one bund wall area.Interior height shall not exceed 1.8 m. If necessary, an additional judgment shall be conducted if a bigger bund wall is needed

6.4 REPORTING, RECORDS AND DOCUMENTATION SYSTEM

During field inspection of Storage tank, the surveyor shall be make anyrecord that described below, following company standard form no. F.SQ-F.008.1 Rev. 0 In-Service Storage Tank Inspection and Verification CheckList and company standard form no. F.SQ-F.008.2 Rev. 0 Out of ServiceStorage Tank Inspection and Verification Check List, but not limited to :


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