BES 800-101

Petrogal MANUAL DE PROCEDIMENTOS Edição:Data:

ESPECIFICAÇÕES DE ENGENHARIARevisão:Data:

BES – Pág. 1 de 25

Mod. Q-03 Reprodução proibidaImpresso a partir da PETRONET

TANKS

00.04.12

00.04.12

0800-101

01

00

Elaborou:R. Westerop

Verificou: Aprovou:

Petrogal MANUAL DE PROCEDIMENTOS Edição: 01Data: 00.04.12

ESPECIFICAÇÕES DE ENGENHARIARevisão: 00Data: 00.04.12

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INDEX

SECTION PAGE

1. SCOPE 4

2. DEFINITIONS 4

3. SUPPLEMENTARY SPECIFICATIONS, CODES AND STANDARDS 5

4. SUPPLIER'S OBLIGATIONS/RESPONSIBILITIES 5

5. DOCUMENTATION 6

6. DESIGN CONDITIONS 7

7. MATERIALS 11

8. MINIMUM THICKNESS 11

9. BOTTOMS 11

10. SHELLS 12

11. ROOFS 12

12. APPURTENANCES 13

13. FLANGED CONNECTIONS 17

14. INTERNALS 18



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15. TANK ATTACHMENTS 18

16. NAMEPLATES 19

17. WELDING 19

18. HEAT TREATMENT 20

19. TOLERANCES 21

20. INSPECTION AND TESTING 21

21. PAINTING 24

22. PREPARATION FOR SHIPMENT 24

23. SPARE PARTS 25

24. LOADING 25

25. STANDARD DRAWINGS 25



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1. SCOPE

1.1 This specification covers the minimum requirements for the design, field/shopfabrication, inspection, testing and documentation of tanks and supplements thespecifications and requirements of the code under which the tanks are to be designed.

1.2 This specification is applicable to tanks with the following characteristics:

! Vertical butt-welded cylindrical shell.

! All welded steel.

! Fixed/floating roof and open top.

! Internal floating cover.

! Storage of nonrefrigerated liquids.

! Maximum design pressure at 1000 mbar.

Tanks may have a storage or a process function and may be shop or field fabricated.

2. DEFINITIONS

Principal : Petróleos de Portugal S.A. (Petrogal) or the company acting onprincipal’s behalf.

Contractor : The party which carries out engineering (if applicable), supply ofmaterials, fabrication and installation/construction.

Supplier : Any manufacturer or supplier who is appointed by the principal orcontractor and responsible for the supply of materials or equipmentor services.

Shall : Is to be understood mandatory.

Should : Is to be understood as strongly recommended.

May be : Is to be understood as giving a freedom of choice.



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3. SUPPLEMENTARY SPECIFICATIONS, CODES AND STANDARDS

3.1 ! Design and construction code and national and/or local regulations as specified inthe requisition.

! The standard drawings attached to this specification.

! Owner's specifications referred to in the requisition.

! Supplier's specifications referred to in the requisition.

3.2 In case of contradiction between code, rules, specification and standards the followingpriority shall apply:

! Code of design and construction.*

! The purchase order requisition, including tank data sheets.

! Suppliers specifications and standards.

Note: * The requirements of this document shall apply if more stringent than thecode requirements.

4. SUPPLIER'S OBLIGATIONS/RESPONSIBILITIES

4.1 Supplier shall design, fabricate field/shop, assemble, test, prepare documentation anddeliver all tanks and accessories to complete the work.

4.2 Supplier shall ensure compliance with the code and authority regulations, including theuse of third party inspection, if necessary and shall obtain local authority approval. Thisincludes delivery of all documents required to satisfy the codes.

4.3 Any deviations from buyer's requisitions, specifications or standards must be submitted tobuyer in writing for approval prior to start the related work.

4.4 Supplier shall execute his services to good engineering practice and workmanship qualitynorms.

4.5 Further obligations/responsibilities are contained in subsequent sections of thisspecification.



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4.6 Buyer's approval of supplier's documents does not relieve supplier of his responsibilitiesfor the services as covered in the requisition.

4.7 Before starting completely shop-fabricated tanks, supplier shall ascertain that shipment ofthe tank to the site is feasible.

4.8 For additional technical requirements, refer to applicable part of the subcontract.

5. DOCUMENTATION

5.1 Copies of properly certified supplier documents as specified on the requirements fordocuments sheets are to be submitted to buyer for review, approval and reference inaccordance with the requisition.

5.2 Each document shall have been checked by supplier's qualified engineers and marked andsigned to that effect. The final, certified, issue shall be signed by the third partyorganisation, if this is required.

5.3 As a minimum, the documents shall cover the following as far as applicable:

a. General arrangement drawing with all construction details.

b. Buyer's purchase order number and relevant equipment item number.

c. Applicable code(s), standards and specifications, including date and revision.

d. Materials of construction, including material standard and type of certificate.

e. Location, size, type, rating, facing and schedule of all connections.

f. Design pressure and temperature, corrosion allowance, joint efficiency,hydrostatic test pressure and hazard category.

g. Position of longitudinal and circumferential welded joints.

h. Welding details and reference to welding procedure.

i. Material finish specification.

j. Actual weights and volume.



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k. Dimensions, including wall thickness.

l. Tolerances.

m. Manufacturer's serial number.

n. Reference to all detail drawings.

o. Detail of nameplate.

p. Extent of heat treatments, radiography and other nondestructive/destructive tests.

q. Gasket make, type and dimensions.

r. Sealing type, make and material of floating roofs.

s. Information marked as "to be confirmed by supplier" in the requisition.

5.4 Revisions shall be clearly indicated with a revision mark as close as possible to themodification.

5.5 Weld details shall identify which welds are shop and which are field applied.

5.6 All drawings and documents must be presented in the English language and in the SIunits of measurement, except as specified in the requisition.Documents and drawings to be submitted to the Portuguese authorities shall be presentedin the Portuguese language.

6. DESIGN CONDITIONS

6.1 PRESSURE

6.1.1 Minimum operating conditions are specified on the individual tank data sheets. Suppliershall design the tank for the design pressures as specified in the requisition.

6.1.2 The minimum hydrostatic test pressure shall be established in accordance with the code.

6.1.3 The term "test pressure" shall apply to the pressure measured at the highest point of thetank in its operating position and shall be applied to the highest point in its test position.



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6.1.4 The design density shall generally be equal to 1. When the product to be stored has adensity higher than 1, the actual density of the product shall be used.

6.2 TEMPERATURE

6.2.1 The design temperature is specified in the requisition.

6.3 CORROSION ALLOWANCE

6.3.1 The corrosion allowance is specified in the requisition.

6.3.2 Corrosion allowance, as specified in the requisition, shall be added to the calculatedthicknesses of bottom, shell and roof, and nozzle necks and flanges of connections. Noadditional corrosion allowance will be provided on flange facings. If blind flanges areused for cover plates, corrosion allowance is required to be added to the standardthickness only in the amount that the specified tank corrosion allowance exceeds 6 mm.

6.3.3 Corrosion allowance shall be added to the cover plates and flange plates of plate-typeinspection openings.

6.3.4 Welded-in nonpressure internal components shall be designed to include the specifiedcorrosion allowance on each surface exposed to tank contents and to permit thecomponent to function in the corroded condition.

6.3.5 Design of removable nonpressure internal components shall include one half of thespecified corrosion allowance on each surface exposed to tank contents.

6.4 WIND AND EARTHQUAKE

6.4.1 The wind pressure for checking the overturning stability shall be based on Regulamentode Segurança e Acçoes para Estruturas de Edificios e Pontes, last edition, and thefollowing procedure:

! The wind velocity at elevation (h) shall be calculated with the formula:

1410

*252.0

+

= hV

h = The height above ground level in meters.V = The wind velocity in meters per second.



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! The wind pressure at elevation (h) shall be calculated with the formula:

2*613.0 VW =

V = The wind velocity in meters per second.W = The wind pressure in Newtons per square meter.

! For round objects, a reduction shape factor shall be established, according to thefollowing criteria:

Shape Factor310** −Wd < 0.15 1.2

310**15.0 −≤ Wd < 0.3 0.6

310**3.0 −≤ Wd < 0.8 0.7

310** −Wd > 0.8 0.8

d = The diameter of the round object in meters.W = The wind pressure in Newtons per square meters.

6.4.2 For design of top and intermediate wind girders, the wind load shall be based on thedesign wind velocity of 100 miles per hour (44.44 m/s) at 30 feet (9.144 m) above groundlevel as specified in API 650, last edition. To calculate the wind velocity at otherelevations, the following formula shall be used:

88.1910

*252.0

+

= hV

h = The height above ground level in meters.V = The wind velocity in meters per second.

6.4.3 The loadings for earthquake conditions shall be calculated according to “Regulamento deSegurança e Acçoes para Estruturas de Edificios e Pontes”, last edition.



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6.4.4 For the Sines location the following will apply:

! Seismic zone : A.

! Seismic coefficient (α) : 1.0

! Nature of terrain : To be defined after geological investigation

For the Porto location the following will apply:

! Seismic zone : D.

! Seismic coefficient (α) : 0.3

! Nature of terrain : To be defined after geological investigation

For constructions in other locations the values indicated in Regulamento de Segurança eAcções para Estruturas de Edificios e Pontes shall be applied.

6.4.5 Wind and earthquake conditions shall not be considered to apply at the same time.

6.4.6 Allowable anchor bolt stress:

Tension 120 N/mm2.Shear 80 N/ mm2.

6.5 ADDITIONAL STIFFENING

6.5.1 For shop-fabricated tanks, supplier shall make a design check and, if necessary, provideadditional stiffening to prevent shell bottom or cover distortion during fabrication,shipment or erection.

6.6 OPENINGS

6.6.1 Openings shall, as required, be reinforced to withstand the design loads to which they willbe exposed, including loads derived from piping stress analysis.



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7. MATERIALS

7.1 All materials used in the fabrication of storage tanks shall have a minimum quality asspecified in the requisition and shall be in accordance with related code/materialspecifications and standards.

7.2 Substitute materials are permitted when approved in writing by buyer.

7.3 All material identification numbers shall be legibly stamped or stencilled preferably onthe long edge of each component. When stamping is required on rolled surfaces, a "lowstress" stamp is to be used.

7.4 The carbon content of all materials to be welded shall not exceed 0.25%.

7.5 Any nonpressure part welded to the tank, such as clips, shall be of similar material as thetank material, or be provided with a pad of similar material as the tank component it isattached to.

7.6 Reinforcement pads shall be made of the same material as the tank.

8. MINIMUM THICKNESS

8.1 The minimum thickness used for construction shall be the larger of the following:

a. The thickness required for pressure plus additional loadings increased by thecorrosion allowance and fabrication tolerances.

b. The minimum thickness specified by the code increased by corrosion allowanceand fabrication tolerances.

8.2 The minimum thickness of nozzle neck shall be the larger of:

a. Standard wall increased by the corrosion allowance.

b. Thickness as specified in the requisition.

9. BOTTOMS

9.1 All bottom plates, including sketch plates, shall have a minimum thickness of 6 mm.



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9.2 The slope of bottoms shall not exceed 12 mm per meter.

10. SHELLS

10.1 The top shell course of all tanks shall have a top angle butt welded or double lap weldedto the top shell course.

10.2 After completion, the inside surface of floating roof tank walls shall be ground to removeany roughness liable to impair the seal.

10.3 Where a second wind girder is required, it shall be provided at a height as specified in theapplicable code.

11. ROOFS

11.1 GENERAL

11.1.1 All roof plates shall have a minimum plate thickness as specified in the code.

11.1.2 All roofs shall be designed for operating loads and live loads according to the code or asspecified in the requisition.

11.2 FIXED ROOFS

11.2.1 Only self-supporting cone or dome-type roofs shall be used, unless specified otherwise.

11.2.2 For cone roof tanks during erection, precautions shall be taken to maintain the slope ofthe roof sheets to the edge of the curb angle to prevent the development of flat areas inthe roof.

11.2.3 Cone roof slope is 1 in 5. Supplier may quote as an alternative other slope proportions.

11.3 FLOATING ROOFS

11.3.1 Type of floating roof shall be either double deck or pontoon type and continuous weldjointed and liquid tight. Alternative designs are subject to buyer's approval.

11.3.2 The design of the roof, platform and appurtenances shall permit filling to the overflowlevel without damaging the roof, seal or any part of the tank.



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11.3.3 The centering device, top shell extension, seal and overflow drainage openings shall bedesigned to enable the tank to overflow while permitting the roof to be guided downwithout damage to the annular seal.

11.3.4 The roof shall be provided with adjustable support legs to support the roof in its lowestposition. The lowest position shall take into account clearance for appurtenances (e.g.mixers, int. pipes, etc.) A second, higher position, shall permit the crews to walk inbetween the bottom and the roof. Bottom plates shall be provided with pads at each legposition.

12. APPURTENANCES

Tanks shall be provided with all appurtenances specified on the individual data sheets forthe specific tanks and comply with the requirements as mentioned in this section.

12.1 MANHOLES

12.1.1 Except as otherwise specified, the number of manholes shall be as shown below:

Tank Diameter Shell Roof

Dia. < 8 m 1 18 > dia. < 36 m 2 2Dia. > 36 m 4 2

Floating roofs, pontoon or double deck shall be provided with manholes to inspect theentire interior of the roofs.

12.1.2 A clean-out door may be installed instead of a manhole if justified by the necessity forfrequent cleaning (e.g. crude-oil tanks). This shall be specified on the tank data sheet.

12.1.3 The inside diameter of a manhole in a fixed roof of a storage tank without floating covermust be ≥ 500 mm; the inside diameter of all other manholes must be ≥ 600 mm.

12.2 DRAW-OFF SUMPS

12.2.1 When specified in tank data sheet, tank bottom shall be provided with draw-off sumps, inaccordance with the code.

12.2.2 Draw-off sumps shall have their nearest outer edge one meter from the shell and shall beat an adequate distance from the product inlet and outlet nozzles.



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12.3 VENTS

12.3.1 Vents without flame arresters shall be provided on all tanks storing products of which theflash point is above 55°C. Their overall capacity shall be determined in accordance withthe provisions of the code and API 2000.

12.3.2 Tanks containing products of which the flash point is below 55°C shall be provided withremovable, metallic cloth vents acting as flame arresters.

12.3.3 Floating roof tanks shall be provided with automatic vents allowing air inlet and exhaustduring emptying and filling of the tank, with the roof in low position. Such vent(s) shallautomatically shut when the roof is made to float.

12.3.4 All open roof and shell openings shall be protected with stainless steel screens againstbirds.

12.4 ROOF DRAINS

12.4.1 Drains of flexible hose or jointed rigid pipe-type discharging at the tank bottom shall beprovided for evacuating rainwater from floating roof tanks. The type of drain to be usedshall be defined by the Principal.

12.4.2 Such drains shall be dimensioned based on the maximum forecast rainfall.

12.4.3 The drain clearance shall be designed so that the drain movements shall not interfere withany internals. It may be guided, if appropriate.

12.5 STAIRWAYS AND PLATFORMS

12.5.1 Structural-steel attachments such as stairway, ladder, platform and hand railing shall be inaccordance with code requirements. Additional requirements are specified on the tankdata sheet. Details shall be in accordance with the structural-steel specification; however,supplier may quote as an alternative his own standards for which full details shall begiven by supplier.

12.5.2 A helical staircase shall provide access to tank roofs, maximum angle with a horizontalline: 45°, with nonslip dismountable treads.

12.5.3 It shall be equipped with a terminal landing giving access to the top side of the roof.Where the vertical rise of the stairways is more than 9 m, intermediate landing orlandings shall be provided.



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12.5.4 All parts attached to the shell shall be continuously welded to prevent corrosion betweenthe shell and the attached part. Any deviations to this requirement shall be explicitlymentioned in supplier's bid and requires buyer's approval.

12.5.5 The staircase shall be clear of the foundations.

12.5.6 Floating roof tanks shall be provided with rolling ladder giving access to the tank roof.

12.5.7 Construction of the rolling ladder shall prevent derailing due to weather conditions orother sources of failure.

12.5.8 Rolling ladder shall be provided with self-orienting grating treads. Stair travel shall beadequate to allow for all roof positions.

12.5.9 The location of the fittings shall not interfere with the ladder travel.

12.6 GROUNDING

12.6.1 The shell shall be provided with grounding lugs complying with the standard drawing.

12.6.2 Floating roof tanks shall be equipped with a link between the shell and the fixed andmoving equipment, such as floating roofs and escalators.

12.6.3 Quantity of lugs is specified in the tank data sheet.

12.7 FLOATING ROOF PERIPHERAL SEAL

12.7.1 The roof peripheral seal shall preferably be of the dry type, filled with polyurethane foam.Other types to be agreed with Principal.

12.7.2 Whatever the type of seal used, the envelope fabric shall be of a material resisting, at50°C, hydrocarbons with an aromatics content of 98% and a sulphur content of 2%.

12.7.3 The seal shall be protected by a ring of wipers consisting of overlapping hinged steelscales rubbing against the shell.

12.7.4 Each protecting scale shall have a louver-shaped cut-out to allow for fire foam if firefoam protection is specified.

12.7.5 The intake area of the louvers shall be of approximately 200 cm².



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12.7.6 Vapour-mounted seals shall have a minimum of two vents to evacuate gas vapours or airpockets from underneath the seal of the floating roof in accordance withAPI standard 2000.

12.7.7 Secondary seals shall be installed to limit the VOC emissions in light product tanksaccording to EC Directive, n. 94/63/CE.

12.7.8 Light product tank external walls and roof shall have a finishing coat with heat reflectioncapacity higher than 70%, according to Portaria 646/97.

12.8 FOAM OUTLET STATIONS

12.8.1 Foam outlet stations, if required, shall be located near the top of the shell; they shallinclude laterals and weirs in the case of fixed roof tanks and deflectors and weirs abovethe top course in the case of floating roof tanks. The number of weirs shall be specifiedby supplier.

12.8.2 A foam dam designed to retain the foam above the roof seal shall consist of a steel plate200 mm higher than the wipers, installed 1 m from the shell inward and attached to thetop part of the floating roof chamber by an intermittent weld. The foam dam shall beprovided with slotted drain holes. Size and number shall be advised by supplier.

12.9 HEATING SYSTEM

12.9.1 Where specified in the requisition, a heating system shall be provided consisting either ofheating coils located on the bottom of the tank or of tube heaters.

12.9.2 The heating coils shall be installed horizontally with a regular slope towards thecondensate discharge at not less than 100 mm below the bottom generatrix of the productinlet and outlet nozzles.

12.9.3 The coils shall be completely butt welded; the use of flanges or screwed fittings is notallowed.

12.9.4 In floating roof tanks, the coils shall be positioned so as to permit free operation of themain drain and clearance for the support legs.

12.9.5 All coils shall be secured to supports resting on the tank bottom through bolted clampspositioned so as to allow free expansion of the assembly.

12.9.6 The supports shall be continuously welded to the bottom.



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12.9.7 The coils shall be spaced not over 600 mm apart. The heating coils shall be installed onlyafter the bottom has been tested.

12.10 CONTROL AND MEASURING INSTRUMENTS

Control and measuring instruments shall be provided as specified in the requisition.

13. FLANGED CONNECTIONS

13.1 The dimensional specifications and the pressure temperature rating of flanges in the sizesup to and including 24" shall be in accordance with ANSI B16.5, "Pipe Flanges andFlanged Fittings". Manhole flanges and clean-out openings may be plate type.

13.2 All nozzle connections shall be flanged. Flanged connections smaller than 1½" shall bereduced from 2" shell connection as per standard drawing.

13.3 Bolted flanges in size larger than 24" shall be specified to API 605 or BS 3293. Acalculation of these flanges according to the code shall be made, if required.

13.4 All special size/designed flanges shall be designed using manufacturer's minimum gasketseating stress or the code value, whichever is greater.

13.5 Slip-on flanges may be used for class 150 rating and at design temperatures in the rangeof 0°C to 260°C.

13.6 Lap joint flanges shall only be used if specified in the requisition.

13.7 Unless internal projections are specified, nozzles are to be cut off flush with the inside ofthe shell, bottom or roof and the inside sharp edge shall be broken.

13.8 Welding neck flanges shall be bored to same dimensions as inside diameter of pipe orplate neck.

13.9 Bolt holes shall straddle the north/south and/or vertical tank axis, unless specificallynoted otherwise.

13.10 Nozzle flanges shall be furnished with gasket surfaces machined to the finish specified inthe requisition.

If flange surface finish is not specified, Supplier shall determine the appropriate finish forthe type of gasket used.



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3.11 BLIND FLANGES

13.11.1 Blind flanges for carbon-steel tanks may be either carbon-steel forgings or plate,furnished dimensionally in accordance with the flange standard specified.

13.11.2 Blind flanges for alloy tanks shall be of the same alloy in sizes up to DN 80. For largersizes, they may be carbon-steel forgings or plate faced with alloy, as shown on standarddrawing.

13.11.3 Each connection specified as "blinded" in the requisition and each manhole shall beprovided with a blind flange, pressure bolting and a service gasket.

13.12 BOLTING

13.12.1 Threads of bolting for ANSI flanges shall be in accordance with ANSI B1.1, class 2A fit.Sizes 1" and smaller shall be coarse thread series and sizes 1-1/8" and larger 8 pitchthread series. Stud bolts to be provided with two heavy hexagonal nuts.

13.13 GASKETS

13.13.1 External gaskets shall be as specified in the requisition.

13.13.2 Internal gaskets shall be graphite internally reinforced, unless otherwise specified inrequisition.

14. INTERNALS

14.1 All removable internals shall pass through manhole(s).

14.2 Hexagon headed bolts, in accordance with ANSI B1.1 with one nut, shall be used forinternal connections. The minimum bolt size is ½”.

15. TANK ATTACHMENTS

15.1 All tank attachments such as insulation supports, piping clips, ladder clips and platformclips, shall be provided by supplier in accordance with the appropriate standards anddrawings.

15.2 Reinforcing pads for internal or external structural attachments to tank shells shall beprovided with a 6 mm diameter vent hole for the enclosed space between welds.



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The internal vent hole shall be plug welded after completion of all welds of the pad.

16. NAMEPLATES

16.1 Tanks shall have separate stainless-steel code and supplier's nameplates permanentlyattached to the tank. Nameplate data shall not be stamped on shell.

16.2 These nameplates shall be mounted on a bracket, as shown on the applicable standarddrawing.

16.3 The nameplate shall be located approximately 300 mm above the lowest man way, unlessotherwise specified in the requisition.

17. WELDING

17.1 Shell plates shall be thus laid out to minimise the number of welds.

17.2 Openings and preferably all attachments and reinforcing pads shall clear longitudinal andcircumferential seams.

17.3 For floating roof tanks, the joints shall be back welded at the inside.

17.4 The vertical joints of the first shell course shall be so located that they do not interferewith the joints in the bottom plates.

17.5 When it is necessary for external attachments to cross tank seams, the attachment weldshall be omitted at the seams subjected to buyer's approval.

17.6 Where a nozzle or other attachment falls within a seam which cannot be relocated,supplier shall notify buyer. Buyer will either relocate the nozzle or attachment, or specifyadditional inspection for the affected seam.

17.7 Shell seams shall be double-welded butt joints, except at those locations where doublebutt welding is not possible. Single-sided welds shall have full penetration.

17.8 Bottom plate and roof plates shall be either lap joint or butt joint.

17.9 Annular plate joints shall be single-sided butt joint with backing strip.



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17.10 The inside surface of the shell shall be formed and matched to be as flush as possible atthe weld seams. Generally, when a difference in thickness exists between shell plates, theinside diameter shall hold.The maximum allowable offset of shell sections shall not exceed code requirements.

17.11 The tank shall be designed to have all courses truly vertical. The distance betweenvertical joints in adjacent courses should not be less than one third of the plate length.

17.12 Nozzles shall be attached to the tank by full penetration welds.

17.13 Attachments such as lugs, clips and seats shall be designed to be welded to the tank shellor roof by continuous fillet welds, for design temperature above 0°C and by continuousfull penetration welds for design temperatures below 0°C.

17.14 Welding may only be executed by qualified welders.

17.15 No welding shall be performed on tanks or parts thereof after stress relieving withoutspecific approval by buyer. Design drawings shall specify that a note to this effect bepainted on the tank.

18. HEAT TREATMENT

18.1 Tanks or parts thereof shall be postweld heat treated, as required by the code.

18.2 Tanks or parts thereof that require additional heat treatment to enhance corrosionresistance or mechanical properties, shall receive these heat treatments when called for inthe requisition or material specification, or when these are a requirement of the materialmanufacturer.

18.3 Supplier shall submit to buyer as part of a fabrication procedure, an outline of theadditional heating operations that tank parts will be subjected to during fabrication.

18.4 Supplier shall notify buyer of any unusual configuration or component design such thathigh stresses may be developed in welds because of restraint. Buyer's approval to omitstress relieving is to be obtained.

18.5 Flange facings must be protected against oxidation during heat treatment.



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19. TOLERANCES

19.1 Tolerances are to be in accordance with the applicable standard drawing and code.

20. INSPECTION AND TESTING

20.1 Buyer's and/or client's inspectors may engage in the inspection of the tank as specified inthe scope of inspection sheet attached to the requisition. The inspectors shall have freeaccess to supplier's and his subcontractor's work at both shop and erection site at allreasonable times and during all tests.

20.2 Welded seams shall be subjected to radiographic examinations, as required by the code.

20.3 Ultrasonic examination, magnetic particle or dye penetrant may be used as an alternativequality assurance method to radiography only where code so permits and whereradiography is not practical. Use as a back-up tool for radiography, or to locate plate orweld defects, is not restricted.

20.4 All heat numbers shall be marked by paint or other legible means in such a way that thesecan easily be noted and read after erection. For bottom plates these shall be on the inside,for all other parts, on the outside.

20.5 PRESSURE TESTS

20.5.1 Minimum test water temperature for carbon or low-alloy steel tanks, shall be 7°C, or 5°Cabove embrittlement transition temperature, when this is higher. Water must be clean,without contaminants.

20.5.2 Each tank shall be hydrostatically tested to the test pressure as per the code.

20.5.3 For field tests, the filling rate, holding time and drainage shall be as per code and owner'srequirements.

Supplier shall, for all field-fabricated tanks, submit a test procedure for approval bybuyer.

20.5.4 For field-fabricated tanks, the following procedure is given as a guideline:

Prior to the tests mentioned below, several levels shall be plotted on the tank bottom, inorder to check the settlement after the tank is emptied.



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All shell nozzles shall be plugged and the tank shall be filled with water. Water-fillingrates and observation times can be as follows:

! Filling to 1/3 of the tank at a rate of 45 cm/h.

! Observing for 24 hours.

! Filling to 2/3 of the tank at a rate of 30 cm/h.

! Observing for 24 hours.

! Filling up the tank at a rate of 25 cm/h.

! Observing for 24 hours, then emptying.

20.5.5 Austenitic stainless-steel tanks shall be tested with water having a maximum chloridecontent of less than 50 ppm. After testing, the tank shall be thoroughly dried. Alternatetest media may be used only with the approval of buyer.

20.5.6 The test pressure shall be maintained for the period specified by the code, but not lessthan half an hour.

20.5.7 Blind flanges, piping components, etc., which supplier has to provide, shall be bolted upand hydrotested together with tank.

20.5.8 Test gaskets shall be the same type as the service gasket, but do not need to be of thesame material if the seating characteristics are similar. Use of a sheet test gasket in lieu ofa spiral-wound, metal-jacketed or similar gasket, is permitted in limited cases, with theprior approval of buyer.

20.5.9 For shop-fabricated tanks the test gaskets may be left in place, but to facilitate entry in thefield, only four bolts shall be installed on manhole flanges to hold cover in place.

Each joint that has been bolted up prior to shipment from the shop, must be provided witha firmly attached tag, listing the type of gasket that has been installed.

20.5.10 Nozzle reinforcing pad welds shall be tested with maximum 0.5 barg air and soap sudssolution.

20.6 Where additional tests are required, such as air or halide tightness test, liquid penetrant ormagnetic particle inspection, these shall be performed in accordance with instructionsgiven in the requisitions and the methods of inspection prescribed in the code.



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20.7 TESTING BOTTOM TIGHTNESS

The bottom shall be tested in accordance with the methods recommended in the code.

Preference is given to the vacuum method with testing box and soap solution.

20.8 TESTING TANK ROOF

20.8.1 Fixed Roof Tanks

Fixed roof tightness testing shall be done in strict accordance with the requirements of thecode.

The pressure shall be strictly controlled using a very accurate pressure gauge during theentire period of the test.

The roof tightness shall be tested by applying a soap solution on all the welds.

The vacuum pressure test shall be performed after emptying the tank down to a low levelof about 1 m.

During emptying, all roof openings shall mandatorily be open. Then, except for the reliefdevices, the openings shall be closed and emptying shall proceed with care until anegative pressure of 2.5 mbar for nonpressure tanks or 6 mbar for pressure tanks isreached. The pressure shall be carefully measured with a pressure gauge.

20.8.2 Floating Roof Tanks

Floating roofs shall be tested in strict accordance with the requirements of the code.

The roof operation shall be tested, as well as the tightness of the seal between the shelland the roof.

20.9 FLOATING ROOF DRAINS

After installation, hose or jointed drains shall be subjected to hydraulic tests at a pressureof 3.5 bar, with the tank empty.

Following the tests the drains shall be cleaned and checked for correct operation.



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20.10 After the initial fill, the bottom distortion shall be approximately as designed (theoreticalestimation of the soil settlement) and shall in no event have sags where large quantities ofliquid can be trapped; if such is the case, repairs shall be considered.

21. PAINTING

21.1 The type of protective internal and external coating for a particular tank shall be asspecified in the requisition.

21.2 The tank shall be cleaned inside and outside of weld spatter, weld slag, flux deposits,burrs and splinters, loose mill scale and all other foreign matter.

21.3 Special care shall be taken that austenitic stainless-steel surfaces do not come into contactwith the primer of carbon-steel parts.

21.4 Steel plates stored pending erection shall be suitably protected against oxidation.

21.5 For field-erected tanks, it is recommended to prime all plates prior to delivery to erectionsite. Heat numbers shall in this case be left unpainted.

21.6 Before erection, the outside surface of bottom plates shall be brushed, degreased, thencoated with hot applied bitumen paint.

21.7 For floating roof tanks supplier shall indicate which type of protection he considers forthe inside of chambers.

22. PREPARATION FOR SHIPMENT

22.1 After completion of fabrication and testing, the shop-fabricated tanks shall be thoroughlydrained of water and dried.

22.2 All parts and prefabricated parts of field-fabricated tanks shall be thoroughly cleaned,match marked and bevelled for welding prior to shipment.

22.3 Carbon-steel flange facings (except on nozzles shipped with gaskets in place), shall becoated with an easily removable rust preventative. All flange facings must be protectedwith temporary shipping covers. Screwed openings shall be protected with a plastic pipethread plug.



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23. SPARE PARTS

23.1 Supplier shall supply 10% spare bolting with a minimum of 2 bolts of each size and type.

23.2 Supplier shall supply 2 spare gaskets for each blinded nozzle and bolted connection.

24. LOADING

24.1 Supplier must ensure that equipment and/or all parts thereof is properly loaded andsecured to the carrier, preventing damages from or cradles, hold-down devices orotherwise, and that clearance requirements are met.

25. STANDARD DRAWINGS

The following standard drawings form a part of this specification:

Drg No. DescriptionSD.0800.101.01 Nozzle Arrangements, 1 of 3SD.0800.101.02 Nozzle Arrangements, 2 of 3SD.0800.101.03 Nozzle Arrangements, 3 of 3SD.0800.101.04 Internal Plate Flanges – Non PressureSD.0800.101.05 Nameplate BracketSD.0800.101.06 Insulation Supports for Storage TanksSD.0800.101.07 Grounding Lug Type 1 & 2SD.0800.101.08 Tolerances for Storage TankSD.0800.101.09 Alloy Liner Details, 1 of 2SD.0800.101.10 Alloy Liner Details, 2 of 2

BES 800-101

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Transcript of BES 800-101