Aramco 1

Previous Issue: 4 April 2010 Next Planned Update: 4 April 2015

Page 1 of 34

Primary contact: Naffaa, Mahmoud Youniss on 966-3-8760183

Copyright©Saudi Aramco 2011. All rights reserved.

Materials System Specification

32-SAMSS-005 26 January 2011

Manufacture of Atmospheric Tanks

Document Responsibility: Vessels Standards Committee

Saudi Aramco DeskTop Standards

Table of Contents

1 Scope............................................................. 2

2 References..................................................... 2

3 Definitions....................................................... 5

4 Materials......................................................... 5

5 Design............................................................ 6

6 Fabrication.................................................... 11

7 Erection........................................................ 12

8 Methods of Inspecting Joints........................ 16

9 Welding Procedure and Welder Qualifications............................ 17

10 Marking......................................................... 18

11 Coatings and Painting.................................. 18

12 Documentation............................................. 19

13 Disinfection................................................... 19 Appendix B – Recommendations for Design and Construction of Foundations for Aboveground Oil Storage Tanks.................. 20

Appendix C – External Floating Roofs............... 21

Appendix G – Structurally Supported Aluminum Dome Roofs................................ 26

Appendix H – Internal Floating Roofs................. 28

Document Responsibility: Vessels Standards Committee 32-SAMSS-005

Issue Date: 26 January 2011

Next Planned Update: 4 April 2015 Manufacture of Atmospheric Tanks

Page 2 of 34

The following paragraph numbers refer to API STD 650, Eleventh Edition, June 2007

with Addendum 1, November 2008, which is part of this specification. The text in each

paragraph below is an addition, exception, or deletion to API STD 650 requirements as

noted. Paragraph numbers not appearing in API STD 650 are new paragraphs to be

inserted in numerical order.

1 Scope

1.1 General

1.1.8 Appendix B and all other pertinent requirements of this specification shall be

used as the basis for developing detailed design and construction of

foundations for storage tanks.

1.1.9 Additional requirements for external floating roofs are contained in

Appendix C of this specification.

1.1.13 Additional requirements for optional self-supporting aluminum dome roofs

are contained in Appendix G of this specification.

1.1.14 Additional requirements for internal floating roofs are contained in

Appendix H of this specification.

1.1.32 This specification shall be attached to and form an integral part of a purchase

order.

1.5 Compliance

1.5.1 Any conflicts between this Specification and other Saudi Aramco Materials

System Specifications (SAMSSs), Saudi Aramco Engineering Standards

(SAESs), industry codes and standards, and Saudi Aramco Standard

Drawings (SASDs) and Forms shall be resolved in writing by the Company

or Buyer Representative through the Manager, Consulting Services

Department of Saudi Aramco, Dhahran.

1.5.2 Direct all requests to deviate from this specification in writing to the

Company or Buyer Representative, who shall follow internal company

procedure SAEP-302 and forward such requests to the Manager, Consulting

Services Department of Saudi Aramco, Dhahran.

2 References

Materials or equipment supplied to this specification shall comply with the latest edition of

the references listed below and those referenced in API STD 650, unless otherwise noted.

http://standards/docs/SAEP/PDF/SAEP-302.PDF




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2.1 Saudi Aramco References

Saudi Aramco Engineering Procedures

SAEP-302 Instructions for Obtaining a Waiver of a

Mandatory Saudi Aramco Engineering

Requirement

SAEP-327 Disposal of Wastewater from Cleaning, Flushing

and Dewatering Pipelines and Vessels

SAEP-1142 Qualification of non-Saudi Aramco NDT

Personnel

Saudi Aramco Engineering Standards

SAES-A-007 Hydrostatic Testing Fluids and Lay-Up

Procedures

SAES-A-102 Air Pollutant Emission Source Control

SAES-A-112 Meteorological and Seismic Design Data

SAES-A-206 Positive Material Identification

SAES-B-017 Fire Water System Design

SAES-B-018 Air Foam Systems for Storage Tanks

SAES-B-067 Safety Identification & Safety Colors

SAES-H-001 Coating Selection & Application Requirements for

Industrial Plants & Equipment

SAES-J-300 Level

SAES-L-105 Piping Material Specifications

SAES-W-017 Welding Requirements for Tanks

Saudi Aramco Materials System Specifications

09-SAMSS-107 Qualification Requirements and Application of

Composite Fluoropolymer/Ceramic Coatings to

Fasteners

32-SAMSS-017 Side-Entry Mixers

34-SAMSS-319 Radar Tank Gauging Equipment

Saudi Aramco Standard Drawings

AB-036003 Manholes and Vents for Tanks




http://standards/docs/SAES/PDF/SAES-A-007.PDF




http://standards/docs/SAES/PDF/SAES-B-017.PDF



http://standards/docs/SAES/PDF/SAES-H-001.PDF

http://standards/docs/SAES/PDF/SAES-J-300.PDF

http://standards/docs/SAES/PDF/SAES-L-105.PDF

http://standards/docs/SAES/PDF/SAES-W-017.PDF

http://standards/docs/SAMSS/PDF/09-SAMSS-107.PDF



http://standards/docs/Standard_Drawings/PDF/AB-036003-001.PDF




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AA-036256 General Assembly of Radar, Temperature, and

Manual Gauging for External Floating Roof

Tanks

AA-036355 Impressed Current Tank Bottom Cathodic

Protection Details

AB-036387 Tank Grounding

Saudi Aramco Inspection Requirements

Form 175-324900 Tanks: Atmospheric, Steel within the Scope of

API STD 650; Except for Tanks according to

Appendix F of the Same Standard

Saudi Aramco Forms and Data Sheets

Form 2696-ENG Layout of Appurtenances

Form NMR-7918-1 Nonmaterial Requirements for Shop and Field

Erected Tanks

Form NMR-7918-2 Nonmaterial Requirements-Floating and Internal

Floating Roofs

2.2 Industry Codes and Standards

American Petroleum Institute

API STD 650 Welded Tanks for Oil Storage

API STD 2000 Venting Atmospheric and Low-Pressure Storage

Tanks

API RP 2003 Protection against Ignitions Arising Out of Static,

Lightning, and Stray Currents

American Society of Mechanical Engineers (Boiler and Pressure Vessel

Code)

ASME B16.11 Forged Fittings, Socket-Welding and Threaded

ASME SEC V Nondestructive Examination

National Fire Protection Association

NFPA 68 Standard on Explosion Protection by Deflagration

Venting

NFPA 255 Standard Method of Test of Surface Burning

Characteristics of Building Materials

http://standards/docs/Standard_Drawings/PDF/AA-036256-001.PDF



http://standards/docs/Inspection_Requirements/PDF/175-324900.pdf

http://standards/docs/Forms_Data_Sheets/PDF/SA-2696.pdf

http://standards/docs/Nonmaterial_Requirements/PDF/SA-7918-1.PDF





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American Water Works Association

AWWA C652 Disinfection of Water Storage Facilities

3 Definitions

Design Engineer: The Engineering Company responsible for specifying the

design requirements on the Storage Tank Data Sheet.

3.4 (Exception) Design Metal Temperature: The lowest of the following

temperature values:

1) The lowest one-day mean atmospheric temperature (LODMAT) per

SAES-A-112, or

2) The minimum operating temperature, or

3) The hydrostatic test temperature

3.19 Saudi Aramco Engineer: The Chairman of the Vessels Standards

Committee.

3.20 Saudi Aramco Inspector: The person or company authorized by the Saudi

Aramco Inspection Department to inspect tanks to the requirements of this

specification.

4 Materials

4.1 General

4.1.2 The Tank Manufacturer shall submit a complete material specification

with the proposal.

The Tank Manufacturer may propose the use of alternative materials to

those that are listed in API STD 650. The alternative materials shall

comply with all the other requirements of API STD 650 and this

specification. The chemical compositions and mechanical properties of

non-ASTM materials shall be submitted to the Saudi Aramco Engineer

for approval.

Materials proposed by the Tank Manufacturer that are equivalent to

those specified in API STD 650 shall be approved by the Saudi Aramco

Engineer.

4.1.3 (Exception) All materials shall be clearly identified and provided with

mill test certificates. Materials shall be alloy-verified by the Tank

Manufacturer in accordance with SAES-A-206.






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4.2 Plates

4.2.1 General

4.2.1.5 Annular plate material shall be of the same material group per

API STD 650 as the lowest shell course.

4.2.1.6 Rimmed and capped steels shall not be used for shell, bottom and roof

plates.

4.7 Bolting

(Exceptions)

a. Flange bolting material shall conform to A193 Grade B7 for bolts

with A194 Grade 2H for nuts.

b. All bolts and nuts used for anchorage shall be coated with a

fluoropolymer/ ceramic coating in accordance with 09-SAMSS-107.

Galvanized bolts and nuts are not acceptable.

4.9 Gaskets

Gasket materials shall be non-asbestos according to SAES-L-105.

5 Design

5.1 Joints

5.1.3 Restrictions on Joints

5.1.3.5 Lap-welded joints shall be lapped at least five times the nominal

thickness of the thinner plate joined; however, with double-welded lap

joints, the lap need not exceed 50 mm (2 in.), and with single-welded lap

joints, the lap shall not be less than 25 mm (1 in.).

5.1.5 Typical Joints

5.1.5.3.a (Exception) Top angles shall be attached to the shell by butt welds with

complete penetration and complete fusion.

5.2 Design Considerations

5.2.7 Information provided by the Design Engineer on the API STD 650

Storage Tank Data Sheet and a completed Saudi Aramco Form 2696-ENG

shall be used for the tank design in accordance with API STD 650 and this

specification.


http://standards/docs/SAES/PDF/SAES-L-105.PDF





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5.2.7 Nozzle Loads

5.2.7.1 Associated piping systems loads shall be specified on the tank data sheet.

5.2.7.2 Tank Manufacturer shall ensure that stresses at nozzle-to-tank

connections, due to piping loads specified on the tank data sheet, are

within the allowable limits.

5.3 Special Considerations

5.3.4 Weld Hardness

Weld hardness testing requirements and acceptance criteria shall be in

accordance with SAES-W-017.

5.3.6 Under-tank leak detection and sub-grade protection

5.3.6.1 Tanks in services other than water shall be provided with under tank leak

detection and sub-grade protection according to API STD 650,

Appendix I. Acceptable construction details are Figures I-1, I-2, I-3, I-6,

I-7, I-8, I-9 and I-10.

5.3.6.2 Flexible membrane leak-barrier (liner) of minimum 1000 microns

(40 mils) thickness compatible with the stored product shall be specified

under the tank bottom. The liner shall be placed in accordance with SASD

AA-036355, extending to the internal top edge of the ring foundation.

5.3.6.3 Joints in the liner shall satisfy the leak tightness, permeability and

chemical resistance requirements for the liner material.

5.3.6.4 Alternative under-tank leak detection and sub-grade protection systems

shall not be permitted without the prior approval of the Saudi Aramco

Engineer.

5.3.7 Reinforcing pads and all other external attachment pads shall have

rounded corners of minimum 50 mm (2 inch) radius. Pads that cover

shell seams shall be provided with a 6 mm telltale hole.

5.4 Bottom Plates

5.4.4 Tank bottom shall be sloped in accordance with the specification

provided on the Storage Tank Data Sheet.

5.4.5 (Exceptions)

3. The drip ring shall be turn down at its outer diameter at a 45-degree

angle.






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4. The top of the drip ring and the top of the tank bottom edge

projection beyond the shell shall be coated with the same coating

system used for the first shell course of the tank in accordance with

SAES-H-001.

5.4.6 Bearing plates shall be provided under all fixed roof support columns.

The bearing plates shall be twice the diameter of the column section with

a minimum 356 mm diameter (14 inch), 12.7 mm (1/2 inch) thick, and

shall be attached to the bottom by 4.8 mm (3/16 inch) continuous fillet

welds.

5.6 Shell Design

5.6.5 Design methods other than the one-foot method and the variable-design-

point method provided in API STD 650 shall be approved by the Saudi

Aramco Engineer.

5.7 Shell Openings

5.7.1 General

5.7.1.10 Number, size, type, and orientation of nozzles and manways shall be in

accordance with SASD AB-036003 and as specified on the Storage Tank

Data Sheet.

5.7.6 Shell Nozzles and Flanges

5.7.6.5 All shell nozzles shall be the API Low Type, unless otherwise specified.

5.8 Shell Attachments and Tank Appurtenances

5.8.2 Bottom Connections

When specified, bottom connections shall be designed in accordance

with API STD 650, Appendix O.

Connections shall be fabricated from elbows; miter joints are prohibited.

Vortex breakers shall be provided for bottom connections.

5.8.5 Roof Venting

5.8.5.1 (Exceptions)

1) Protection of fixed roof tanks with internal floating roof shall be as

follows:






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a. Where circulation venting arrangement per Appendix H,

API STD 650, is installed, no additional pressure/vacuum

venting devices is required.

b. Where circulation venting arrangement per Appendix H,

API STD 650, is not installed, pressure/vacuum venting

devices shall be provided. Pressure/vacuum devices shall be

designed for normal and emergency conditions according to

API STD 2000.

2) Protection of External floating roof tanks shall be according to

Appendix C (paragraph C.3.9) of this specification.

3) Protection of Internal floating roof tanks shall be according to

Appendix H (paragraph H.5.2) of this specification.

5.8.9 Threaded Connections

Threaded and socket welded connections shall be in accordance with

ASME B16.11.

5.8.10 Platforms, Walkways, and Stairways

5.8.10.1 Type and location of stairway shall be as specified on the Storage Tank

Data Sheet and Saudi Aramco Form 2696-ENG.

5.8.10.2 Stairs and platforms shall be fabricated of open grating. Checker-plate

grating is not permitted.

5.8.10.3 Walkways shall be fabricated of diamond-pattern (checker-plate) grating

with anti-skid paint.

5.8.10.4 Stairways on tanks shall be provided with stringers and handrails on both

sides.

5.8.11 Other Appurtenances and Attachments

5.8.11.2 (Exception) An inlet diffuser shall be provided for tanks with internal

floating roofs. For relevant design aspects, refer to Appendix H of this

specification.

5.8.11.3 Tanks in hydrocarbon services shall be provided with grounding lugs in

accordance with SASD AB-036387 at a minimum of four points spaced

equidistantly around the base of the tank.

The design of bonding shunts between the tank shell and the roof shall be

in accordance with SASD AB-036387 and API RP 2003 requirements.







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5.8.11.5 Mixers

5.8.11.5.1 Number and type of mixers shall be as specified on the Storage Tank

Data Sheet.

5.8.11.5.2 Side-entry propeller mixers shall be designed, inspected, and tested in

accordance with 32-SAMSS-017.

5.8.11.5.3 Nozzles for side-entry mixers shall be designed in accordance with

API STD 650 for manways. Supports for the mixer may be needed to

maintain stresses at the nozzle-to-shell junction within the allowable

limits.

5.8.11.5.4 Jet-nozzle mixers shall not be used in tanks with internal floating roofs

on floats.

5.8.11.6 Foam and Water Systems

Fire or cooling water and foam systems shall be provided in accordance

with SAES-B-017 and SAES-B-018, respectively, when specified on the

Storage Tank Data Sheet.

5.8.11.7 Gauging

5.8.11.7.1 External-floating roofs shall be provided with a radar gage assembly in

accordance with SASD AA-036256 and SAES-J-300.

5.8.11.7.2 External floating roof tanks shall be provided with a radar liquid level

gauge in accordance with 34-SAMSS-319, located adjacent to the

gauger's platform. The top of the gauge piping shall be located from

150 mm (6 inch) to 300 mm (12 inch) above the platform handrail and

approximately 150 mm (6 inch) horizontally from the gauger's platform

for easy maintenance access.

5.8.11.7.3 Fixed-roof tanks shall be provided with a radar gauge assembly.

5.9 Top and Intermediate Wind Girders

5.9.7 Intermediate Wind Girders

5.9.7.1 The minimum required thickness for the design condition, excluding

corrosion allowance, shall be used to calculate the maximum height of

unstiffened shell.

5.10 Roofs

5.10.2 General





http://standards/docs/SAES/PDF/SAES-J-300.PDF





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5.10.2.1 Type of roof shall be as specified on the Storage Tank Data Sheet.

5.10.2.6.a(4) (Exception) The roof-to-top angle compression ring is limited to details

(d) or (e) in Figure F-2.

5.10.2.6.b(2) (Exception) The tank shall meet the requirements of 5.10.2.6.a(2-5),

except that the roof-to-top angle compression ring is limited to details (d)

or (e) in Figure F-2.

5.10.2.6.c(1) (Exception) The tank shall meet the requirements of 5.10.2.6.a(1-5),

except that the roof-to-top angle compression ring is limited to details (d)

or (e) in Figure F-2.

5.10.2.6.d (Exception) For anchored tanks of any diameter, the tank shall meet the

requirements of 5.10.2.6.a and the anchorage and counterweight shall be

designed for 3 times the failure pressure calculated by F.6 as specified in

5.12. The roof-to-top angle compression ring is limited to details (d) or

(e) in Figure F-2.

5.10.2.10 When an internal coating is specified for a fixed roof, a self-supported

roof shall be used, and the roof lap joints shall be continuously welded

on both sides.

5.10.4 Supported Cone Roofs

5.10.4.6 (Exception) Only welded joints are permitted for all structural

attachments in the roof supporting system other than the following joints:

a) Rafter clips for the outer row to the tank shell.

b) Column-base clip guides to the tank bottom.

5.10.5 Self-Supporting Cone Roofs

Only welded joints are permitted for all structural attachments in the roof

supporting system.

5.10.6 Self-Supporting Dome and Umbrella Roofs

Only welded joints are permitted for all structural attachments roofs'

supporting systems in self-supporting roofs, except for self-supporting

aluminum dome roofs.

6 Fabrication

6.1 General




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6.1.1 Workmanship

6.1.1.4 All flange bolt holes shall straddle the axial centerline of the tank.

6.1.4 Marking

6.1.4.1 Marking shall be done with water soluble materials containing no

substances that would attack or harmfully affect the tank at both ambient

and operating temperature.

6.1.4.2 Marking materials shall be free of lead, sulfur, zinc, cadmium, mercury,

chlorine or any other halogens.

6.1.5 Shipping

All flange faces and other machined surfaces shall be greased and

properly protected for shipping.

6.2 Shop Inspection

6.2.3 Saudi Aramco Inspector shall have the right to inspect the fabrication at

any state and to reject material or workmanship, which does not conform

to the specified requirements.

7 Erection

7.1 General

7.1.7 The bottom side of the bottom plates shall be cleaned of all foreign

matter and grit-blast cleaned prior to being coated and placed in position

for welding. The topside surface of bottom plates, regardless whether

coating is required or not, shall also be grit-blast cleaned prior to

welding. Surface preparation shall be according to APCS-3 or

APCS-113, as applicable.

7.2 Details of Welding

7.2.1 General

7.2.1.11 Documentation that details the welding sequences for the tank shall be

provided to Saudi Aramco prior to the start of field erection.

7.2.1.12 All structural attachment welds to the tank shell, bottom, roof, and

appurtenances shall be continuously seal welded.

7.2.1.13 All welds shall be free from coarse ripples, undercuts, grooves, overlaps,




Page 13 of 34

abrupt ridges and valleys to avoid stress concentration points and

interference with interpretation of NDT results.

7.2.2 Bottoms

7.2.2.4 Weld crowns of the bottom annular plate joints shall be ground flush at

the contact areas with the first shell course.

7.2.4 Shell-to-Bottom Welds

7.2.4.1

1) The initial weld pass inside the shell shall be examined for its

entire length prior to welding the first weld pass outside the shell

(temporary weld fit-up tacks excepted) both visually and by one of

the following methods:

a. Wet-fluorescent magnetic particle.

b. Dye-penetrant.

c. Applying a vacuum test at 35 kPa gauge (5 psig), using a

right angle vacuum box.

d. Applying high flash-point penetrant oil such as light diesel oil

for a minimum 4 hours (preferably overnight).

Note: After completion of penetrating oil test, all residual oil on the applied surfaces shall be thoroughly cleaned before commencing subsequent welds to avoid their possible contamination.

2) The initial weld pass outside the shell shall be examined for its

entire length both visually and by the dye-penetrant method.

3) After completing all welds (inside and outside) and prior to

hydrotest, the inside fillet welds shall be examined for its entire

length both visually and by either dye-penetrant or wet-fluorescent

magnetic particle method.

7.2.4.2 Delete this paragraph.


7.2.5 Roofs

7.2.5.1 Internal floating roofs shall be installed in accordance with the

instructions provided by the internal floating roof manufacturer.




Page 14 of 34

7.2.5.2 Prior to the installation of fixed roof plates, roof's column supports shall

be inspected for plumbness. Roof support columns with out-of-

plumbness exceeding 1/200 of the total tank shell height shall be

realigned.

7.2.5.3 All internal clips, lugs, brackets etc. that are used temporarily for

construction purposes shall be removed from the roof supporting

columns and shell plates and ground flush and smooth prior to roof

installation.

7.3 Inspection, Testing, and Repairs

7.3.1 General

7.3.1.1 Inspection shall be in accordance with Saudi Aramco Inspection

Requirement Form 175-324900, SAES-W-017 and the following

additional requirements.

7.3.1.5 All required Nondestructive Examination shall be performed in

accordance with inspection procedures that are in complete compliance

with ASME SEC V and this specification. This written procedure shall

address each inspection method and technique used including acceptance

criteria. When required by the purchase order the procedure(s) shall be

submitted to Saudi Aramco Inspection Department for approval.

7.3.1.6 All Nondestructive Examination, including Magnetic Particle and Liquid

Penetrant examinations, shall be performed by personnel certified in

accordance with SAEP-1142, or equivalent National Certification

Programs that has been approved by the Saudi Aramco Inspection

Department. Personnel responsible for interpretation of Nondestructive

Examination results shall be certified to a minimum of Level II.

7.3.1.7 Prior to final inspection and pressure testing, the inside and outside of

the tank shall be thoroughly cleaned of all slag, scale, dirt, grit, weld

spatter, paint, oil, etc.

7.3.1.8 Saudi Aramco Inspector may reject the use of any materials, equipment,

or tools that do not conform to the specification requirements, jeopardize

the safety of personnel, or impose hazard or damage to Saudi Aramco

property.

7.3.1.9 Testing shall be in accordance with Saudi Aramco Inspection

Requirements Form 175-324900 and the following additional

requirements.







Page 15 of 34

7.3.3 Examination and Testing of the Tank Bottom

(Exception) Only vacuum box test method is permitted.

7.3.5 Testing of the Shell

7.3.5.1 (Exception) Only water shall be used as a media for testing the tank

shell. Quality of water used in the test shall be in accordance with

SAES-A-007. Testing of the shell by a method other than hydrotesting

such as painting with highly penetrating oil, applying vacuum or a

combination of both methods is not permitted.

7.3.5.2 Hydrostatic testing duration shall be minimum 24 hours.

7.3.5.3 Floating roof seals, either primary or secondary, if required per

SAES-A-102, shall be completely contained within the shell when the

test water level reaches the test liquid level.

7.3.5.4 The tank shall be completely drained and thoroughly dried immediately

after completion of the hydrostatic test. If sea water or raw water is used

for hydrostatic testing of tanks not designated for water services, the tank

shall be thoroughly washed with fresh water immediately after draining.

7.3.5.5 The Tank Manufacturer's plan for disposal of hydrotest water shall be

evaluated against SAEP-327 by the engineering contractor.

7.3.6 Hydrotstatic Testing Requirements

7.3.6.1 (Exception) Any welded joints above the test-water level shall be

examined for leakage in accordance with paragraph 7.3.7 of this

specification.


7.3.6.5 (Exceptions)

1) The maximum filling rate shall be restricted by:

a. Venting requirements (paragraph 5.8.5).

b. Discharge velocity of the incoming stream to 1 m/sec (3.28

ft/sec) until there is a minimum of 1 m of water cover over

the inlet.

2) Settlement measurements shall be specified. All six sets of

readings are required.







Page 16 of 34

7.3.6.6 (Exception) Settlement measurements shall be specified. Measurements

exceeding the limit shall be reviewed by Saudi Aramco Engineer.

Filling shall be stopped until clearance to continue has been received

from the Saudi Aramco Engineer.

7.3.7 Testing of the Roof

7.3.7.1 (Exception) All roof weld joints of a tank designed to be gas tight shall

be tested by applying internal air pressure. Vacuum box testing is not

acceptable.

7.3.7.2 (Exception) All roof weld joints of a tank not designed to be gas tight,

such as a tank with peripheral circulation vents or a tank with free or

open vents, shall be vacuum box tested. Applying internal pressure for

the detection of leaks is not permitted. External floating roof testing

shall be in accordance with Appendix C of this specification. Internal

floating roof testing shall be in accordance with Appendix H of this

specification.

7.4 Repairs to Welds

7.4.5 Repairs to welds shall be in accordance with SAES-W-017.

8 Methods of Inspecting Joints

8.1 Radiographic Method

8.1.1 Application

(Exceptions)

1) For basic design tanks, radiographic inspection for weld joining the

top angle to the shell shall as follows:

a) One in the first 3 m (10 ft) and one in each 30 m (100 ft)

thereafter.

b) 25% of intersections with vertical welds in top shell course

and welds joining sections of top angle.

2) For Appendix F storage tanks, radiographic inspection of the shell-

to-roof juncture shall be as follows:

a) Entire length of weld joining the top angle to the shell.

b) All intersections of weld joining the top angle to the shell with

vertical welds in shell and welds joining sections of top angle.





Page 17 of 34

3) Welds joining top-angle sections, tension rings, and compression

rings shall be fully radiographed.

8.1.2 Number and Location of Radiographs

8.1.2.4 (Exception) This requirement is permitted only if a group of tanks are

erected by the same tank manufacturer.

8.1.5 Radiographic Standards

Tungsten inclusions in gas tungsten arc welds shall be evaluated as

individual rounded indications. Clustered or aligned tungsten inclusions

shall be removed and repaired.

8.1.6 Determination of Limits of Defective Welding

The additional spots to be radiographed shall be specified by the Saudi

Aramco Inspector in accordance with SAES-W-017.

8.2 Magnetic Particle Examination

8.2.5 Magnetic Particle Examination shall be according to SAES-W-017.

8.5 Visual Inspection

Welds shall be visually inspected for any defects prior to performing

nondestructive examination (radiography, magnetic particle, liquid

penetrant, ultrasonic). Visual inspection shall not replace any required

nondestructive examination.

8.6 Vacuum Testing

8.6.3 (Exception) A partial vacuum of 70 kPa gauge (10 psig) shall be used for

the test.

8.6.11 Delete this paragraph.

9 Welding Procedure and Welder Qualifications

9.2 Qualification of Welding Procedures

9.2.1 General Requirements

9.2.1.1 All welding procedures and procedure qualifications shall be in

accordance with SAES-W-017 and be submitted for review by Saudi

Aramco.







Page 18 of 34

10 Marking

10.1 Nameplates

10.1.5 All tanks with internal coatings shall have the Approved Protective

Coating Systems specification number (APCS number) marked on the

nameplate.

10.4 Tank number and content shall be painted in both Arabic and English at

90 degree intervals around the tank in accordance with SAES-B-067.

10.5 Marking shall be done with water soluble materials containing no

substances that would attack or harmfully affect the tank at both ambient

and operating temperature.

10.6 Marking materials shall be free of lead, sulfur, zinc, cadmium, mercury,

chlorine, or any other halogens.

11 Coatings and Painting

11.1 Type of coating and painting systems to be applied shall be as specified

on the Storage Tank Data Sheet.

11.2 Surfaces to be coated shall be cleaned and prepared prior to its coating in

accordance with the applicable coating and painting systems.

11.3 The soil side of all tank bottom plates including annular ring plates shall

be coated with APCS-3 or APCS-113A. APCS-3 shall be specified for

tank with maximum operation temperature of 70°C, while APCS-113A

shall be specified for higher operation temperatures up to 140°C. Soil

side edges of all bottom plates (lap-welded) and annular ring plates (butt-

welded) shall be left uncoated approximately 50 mm wide. This will

typically require masking a strip along the underside of each end (edge)

of each bottom/annular ring plate approximately 50 mm wide.

11.4 In tanks where there is a potential of water accumulation top side of the

bottom and the bottom portion of the shell, starting from the tank bottom

up to minimum one foot above water line, shall be coated according to

the applicable coating specifications per SAES-H-001.

11.5 Top surface of carbon steel floating roofs shall be coated to provide

protection against atmospheric corrosion.

11.6 Gasket contact surfaces shall not be coated or painted.






Page 19 of 34

12 Documentation

The Tank Manufacturer and internal floating roof manufacturer shall prepare drawings,

calculations, and data in accordance with Form NMR-7918-1 and Form NMR-7918-2,

Non-Material Requirements, as applicable.

Drawings and calculations, which are approved by the Design Engineer, shall not relieve

the Manufacturer of the responsibility to comply with the Code and this specification.

13 Disinfection

13.1 All potable water storage tanks shall be disinfected in accordance with

AWWA C652.

13.2 The chlorine and bacteriological tests shall be approved by the

Environmental Health Department of Saudi Aramco.

Revision Summary 4 April 2010 Major Revision. 26 January 2011 Editorial revision to be in line with the ongoing effort to eliminate single sourcing.






Page 20 of 34

Appendix B – Recommendations for Design and Construction of Foundations for Aboveground Oil Storage Tanks

B.2 Subsurface Investigation and Construction

B.2.6 Top fill layer 10-15 cm (4-6 inch) shall be a mixture of sweet sand and

3% cement (33:1 ratio by weight, i.e., 3% cement). The material

specifications and mixing requirements shall be as follows:

1) The maximum permissible salt content is 0.1%. Sand shall be

dried to a free-moisture content of not more than 2.0% by weight of

dry soil.

2) The dry sand must be screened through 6.4 mm (1/4 inch) mesh

(maximum). Care must be taken in using clean mixing and

handling equipment to ensure mixture remains free from foreign

matter.

3) The sand shall then be thoroughly mixed with cement in a concrete

mixer. After placing the mixture shall be rolled a minimum six

times by a 3-ton roller. Vibratory plate tampers may be used in

lieu of rollers for areas where a roller cannot reach and/or cover.




Page 21 of 34

Appendix C – External Floating Roofs

C.2 MATERIAL

(Exceptions)

Galvanized parts shall not be used.

Electrical bonding shunt materials shall be Type 304 stainless steel.

C.3 DESIGN

C.3.1 General

C.3.1.6 Bonding shunts shall be provided on floating roofs in accordance with

SASD AB-036387 and API RP 2003 requirements.

C.3.3 Decks

C.3.3.1 (Exception) Roofs in all services shall be of the contact type designed to

eliminate the presence of any air-vapor mixture under the deck.

C.3.3.7 Roofs greater than 91 m (300 foot) in diameter shall be of the double-

deck type.

C.3.7 Ladders

(Exception) The minimum inside width of the rolling ladder shall be

710 mm (28 inch).

C.3.8 Roof Drains

C3.8.1 Primary Roof Drains

C3.8.1.1 (Exception) External floating roofs (single-deck or double-deck) shall be

provided with a primary (closed) drain system that will direct rain water

outside the tank (does not allow direct drain into the stored liquid).

Capacity of roof drain shall be based on the meteorological data

according to SAES-A-112 at the tank’s location.

C3.8.1.2 Primary roof drains shall meet the following:

1) Materials of construction are compatible with the service,

2) Operates without interruption to service (free from catching on any

internal appurtenance or obstruction during operation, and from






Page 22 of 34

being crushed by landing legs on the bottom),

3) Does not float or induce kinking,

4) Has repeatable lay pattern that allows continued withdrawal of rain

water from the floating roof,

5) Experiences no mechanical wear or binding, and

6) Does not induce lateral forces on the floating roof.

C3.8.1.3 (Exception) Acceptable types of primary roof drains are:

1) Articulated pipe type (steel swing or pivot-jointed pipe drains,

designed and packed for external pressure),

2) Flexible pipe type (stainless steel armored hose).

C3.8.2 Emergency Roof Drains

(Exception) Emergency drains shall be sealed at all times except for

permitting rain water passage. This is to meet the intent of minimizing

vapor loses when there is no draining.

C.3.9 Vents

C.3.9.1 As a minimum, two overpressure/vacuum bleeder type vents shall be

installed. Vents shall be sized to handle a total of 125% of the maximum

filling/withdrawal rates that are specified on the Storage Tank Data

Sheet. Bleeder vents shall be designed to open and close automatically

when the roof is 75 mm (3 inch) above its low support legs position upon

emptying and filling the tank, respectively.

C.3.9.2 Vents for protection against overpressure/vacuum, while the roof is

floating, shall be provided as follows:

1) Their overall capacity shall be determined according to

API STD 2000 requirements, considering 25% of the

filling/emptying rates plus 25% of thermal breathing capacity of a

fixed roof tank with same storage capacity.

2) Vents shall be evenly distributed and close to the roof periphery

enough vents shall be provided close to the inlet diffuser in services

where gas slugs are expected.

3) Minimum number and sizes of vents shall be as follows:




Page 23 of 34

Nominal Tank Diameter D (ft) Minimum Number Size (NPS)

D ≤ 140 2 4

140 < D ≤ 275 2 6

D > 275 4 6

4) Vents shall be designed so as not to allow any carry over of stored

liquid onto the floating roof.

Commentary Notes:

i) Normally, vents are of the type that does not require undergoing shop testing but rather in-situ inspection. In case relief valves are used, their number shall be such that the total required venting capacity is always available considering removal of valve(s) for testing.

ii) Anticipated operation upset conditions such as an increase in temperature of the input stream to a tank or chemical injection that will result in vaporization beyond that associated with the true vapor pressure design limit of 90 kPa (13 psia) and gas purges shall be also considered in determining the required venting capacity.

C.3.10 Supporting Legs

C.3.10.3 (Exception) The higher position shall provide a 2 m (79 inch) clearance

between the lowest portion of the roof and the tank floor.

C.3.10.5 (Exception) The bearing plates shall be twice the diameter of the support

section, 12.7 mm (1/2 inch) thick, and shall be attached to the bottom by

4.8 mm (3/16 inch) continuous fillet welds.

C.3.11 Roof Manholes

(Exception) Roof manways shall be provided in accordance with

AB-036003. All manways in roof shall be kept closed at all times except

during inspection.

C.3.13 Peripheral Seals

C.3.13.1

1) Any fabric or non-metallic materials used as a seal or seal

component shall be selected based on the design temperature,

flammability, permeability, abrasion resistance, aging, resistance to

aromatics, and chemical resistance, and selected from the following

Table:





Page 24 of 34

Seal Materials Table

Fluid Stored Non-Metallic Seal Material

Crude Oil

Fluoroelastomer based on a Terpolymer of Vinylidene difluorideVF2/Hexafluoropropylene,HFP/Tetrafluoroethylene,TFE

Copolymer of tetrafluoroethylene and propylene ("TFE/P")

Refined Products

Fluoroelastomer based on a Dipolymer of VF2/HFP

Polytetrafluoroethylene, PTFE, laminate

Gasoline/MTBE Blend

PTFE (Teflon) laminate

A copolymer of ethylene, tetra-fluoroethylene and perfluoromethylvinyl ether, and a cure site monomer; peroxide cure site.

MTBE (100%)

Polytetrafluoroethylene laminate


2) Fabric or non-metallic materials used as a seal or seal component

shall be tested for their compatibility with the intended service by

an independent laboratory.

3) The Tank Manufacturer may offer an alternate design and material

at the time of proposal. However, the alternate design shall comply

with the following requirements:

a) Seals shall be located on the skirt.

b) Materials for non-metallic components of seals shall meet

requirements in paragraph C.3.13.1 (2) above.

4) All fabric or non-metallic materials used as a seal or seal

component shall have a flammability spread index not exceeding

25 established per NFPA 255.

C.3.13.5 (Exception) If the sealing device employs steel shoes in contact with the

shell, such shoes shall be made of only Type 304 stainless steel with a

minimum nominal thickness of 1.5 mm (16 gauge).

Components of mechanical sealing systems, above stored liquid level,

shall be completely electrically isolated to prevent static electricity

sparking at pivot joints and possible arcing between the roof and the seal

shoe. This shall be accommodated by providing low-density service

compatible polymer type plastic insulation cover or sleeving.




Page 25 of 34

C.3.14 Gauging Device

(Exception) Gauging devices shall be provided per paragraph 5.8.11.7 of

this specification.

C.4.3 The roof shall be given a flotation test while the tank is being filled with

water and emptied during hydrostatic test to confirm that it travels freely

to its full height. The peripheral seal shall be checked for proper

operation throughout the entire travel of the roof. During this test, the

upperside of the lower deck shall be examined for leaks. The appearance

of a damp spot on the upper side of the lower deck shall be considered

evidence of leakage.




Page 26 of 34

Appendix G – Structurally Supported Aluminum Dome Roofs

G.1 General

G.1.4 Special features

G.1.4.2 (Exception) The aluminum dome roof materials shall have a mill finish.

G.2 Materials

G.2.1 General

(Exception) Materials for all roof components shall be compatible with

the intended service. Alternate material for any roof component

(structural frame, roof panels, node covers, bolts, fasteners, sealant and

gasket material, and skylight panels) shall not be used without prior

approval of the Saudi Aramco Engineer, as defined in Section 3 of this

specification.

G.2.2 Structural Frame

(Exception) Structural frame members shall be fabricated from 6061-T6

aluminum.

G.2.3 Roof Panels

(Exception) Roof panels shall be fabricated from 3003 H16 aluminum

with a minimum nominal thickness of 1.2 mm (0.05 in.). Node covers

shall be fabricated from 3003 H14 aluminum with a minimum thickness

of 1.2 mm (0.05 in.).

G.2.4 Bolts and Fasteners

(Exceptions)

a) Bolts and fasteners shall be of 7075-T73 aluminum, 2024-T4

aluminum, or 300 Series stainless steel (AISI 302 or AISI 304).

b) Only 300 Series stainless steel (AISI 302 or AISI 304) bolts shall

be used to attach aluminum to steel.




Page 27 of 34

G.3 Allowable Stresses

G3.2 Aluminum Panels

(Exception) Panels shall be attached to the dome structure (struts)

continuously along the panel edge and secured with a batten as part of an

interlocking joint to prevent slipping or disengagement. Attachment of

panels to the dome structures (struts) along the panel edge at discrete

points with fasteners that penetrate the panel surface is prohibited.

G.4 Design

G4.1 Design Principles

G4.1.5 The dome surface paneling shall be designed as a watertight system

under all design load and temperature conditions.

G.5 Roof Attachment

G.5.3 Separation of carbon Steel and Aluminum

(Exception) Aluminum shall be isolated from carbon steel by austenitic

stainless steel spacers or an elastomeric isolator-bearing pad in roof-to-

shell attachments.

G.10 Testing

G.10.2 100% liquid penetrant examinations shall be performed on structural

welds and components joined by welding.

G.11 Fabrication and Erection

G.11.5 Erection

(Exception) Structural frame members (struts) shall be joined at nodes by

preset-torque level HV-HUCK-Lock bolts.

G.11.6 Workmanship

(Exception) Sealant shall be applied and installed in a manner suitable to

that of architectural class work. Joint surfaces shall be clean to ensure

adhesion of sealants. All exposed sealant surfaces shall be tooled

slightly concave after sealant is placed in joints. Misplaced excess

sealant shall be removed.




Page 28 of 34

Appendix H – Internal Floating Roofs

H.1 Scope

(Exception) Types of internal floating roofs are limited to those specified

in paragraph H.2.2 of this specification. Other types stipulated or

referenced in API STD 650, Appendix H shall not be considered.

H.2 Types

H.2.1 (Exception) The internal floating roof shall be selected by the design

engineer.

H.2.2 (Exception) Only type c(metallic pontoon roofs), type d(metallic double-

deck roofs) or type e(metallic roofs on floats) shall be used.

H.3 Material

H.3.1 (Exception) The Design Engineer shall specify the materials required.

Internal floating roofs with non-metallic components as part of the floats

are prohibited.

H.3.2 Steel

(Exception) Galvanized components shall not be used.

H.3.3 Aluminum

(Exceptions)

Aluminum shall not be used in services where caustic constituents are

present in the stored liquid.

Delete reference to sandwich panel type.

H.4 Requirements for All Types

H.4.1 General

H.4.1.6 (Exceptions)

1) A minimum of four anti-static stranded stainless steel cables of

minimum 3 mm in diameter, uniformly distributed, shall be

provided from the fixed roof to the internal floating roof. Design




Page 29 of 34

of the cables shall take into account strength, flexibility, joint

reliability and service life.

2) The cable used for bonding all moveable cover accessories shall be

minimum 3.2 mm (1/8) in diameter of stranded stainless steel, with

a length at least twice the normal travel of these device covers.

Design of the cables shall take into account strength, flexibility,

joint reliability and service life.


All closed floating compartments shall be seal welded to prevent liquid

or vapor entry.

Delete reference to floating roof type H.2.2.g.

H.4.1.9 Delete this paragraph.

H.4.1.10 (Exception) Drains for decks surfaces above the liquid level shall be

designed to return any spillage or condensate to the product. Such drains

shall close automatically or extended at least 100 mm (4 in.) into the

product to minimize vapor loss.

H.4.2 Internal Floating Roof Design

H.4.2.1 Buoyancy Requirements

H.4.2.1.3 Delete reference to floating roof type H.2.2.g.

H.4.3 Joint Design

H.4.3.3 (Exception) Pivot joints that allow flexure between adjacent floats shall

be provided on internal floating roof designs that employ a metallic roof

on tubular floats.

H.4.3.3.1 (Exception) Only austenitic type stainless steel SS 304 hardware shall be

used to join aluminum and/or stainless components to each other or to

carbon steel.

H.4.4 Peripheral Seals


1) The peripheral seal type and material shall be selected by the

Design Engineer.





Page 30 of 34


flammability, permeability, abrasion resistance, aging, resistance to

aromatics, and chemical resistance, and selected from the following

Table:

Seal Materials Table

Fluid Stored Non-Metallic Seal Material

Crude Oil

Fluoroelastomer based on a Terpolymer of Vinylidene difluorideVF2/Hexafluoropropylene,HFP/Tetrafluoroethylene,TFE

Copolymer of tetrafluoroethylene and propylene ("TFE/P")

Refined Products

Fluoroelastomer based on a Dipolymer of VF2/HFP

Polytetrafluoroethylene, PTFE, laminate

Gasoline/MTBE Blend

PTFE (Teflon) laminate


MTBE (100%)

Polytetrafluoroethylene laminate


3) Fabric or non-metallic materials used as a seal or seal component

shall be tested for their compatibility with the intended service by

an independent laboratory.

4) The Tank Manufacturer may offer an alternate design and material

at the time of proposal. However, the alternate design shall comply

with the following requirements:

a) Seals shall be located on the skirt.

b) Materials for non-metallic components of seals shall meet

requirements in paragraph H.4.4.2 (2) above.

5) All fabric or non-metallic materials used as a seal or seal

component shall have a flammability spread index not exceeding

25 established per NFPA 255.

H.4.4.4 Types of Primary Seals

(Exceptions)






Page 31 of 34

permeability, abrasion resistance, aging, flammability, resistance to

aromatics, and chemical resistance, and selected from the table in

paragraph H.4.4.2 of this specification.

2) Only resilient foam-filled liquid-mounted and vapor-mounted rim

seals shall be used.

3) Circumferential joints in envelope fabric seals shall overlap by at

least 150 mm (6 in.).

4) Galvanized steel components are prohibited.

H.4.4.5 (Exception) All fasteners used in sealing devices shall be Type 304

stainless steel.

H.4.5 Roof Penetrations

(Exception) All roof penetrations shall be surrounded by a well that

extends at least 100 mm (4 in.) into the stored liquid.

H.4.6 Roof Supports

H.4.6.1 (Exception) The floating roof shall be provided with fixed or adjustable

supports.

H4.6.2 (Exception) The height of the floating roof shall be adjustable to two

positions with the tank out of service. The design of the supports shall

prevent damage to the fixed roof and floating roof at the tank maximum

design liquid level.

H.4.6.3.2 (Exception) Where propeller-type mixers are used, the support legs shall

provide a minimum clearance of 300 mm (12 inch) from the underside of

the internal floating roof to the top of the mixer paddle(s).

H.4.6.4 (Exception) Delete reference to floating roof types H.2.2.a, b and g.

H.4.6.5 (Exception) Drainable pipe supports shall be used.

H.4.6.6 (Exception) Steel bearing plates shall be provided under all support legs

so as to distribute the weight of the internal floating roof on the tank

bottom plates and to avoid damage to internal tank coatings. The

bearing plates shall be twice the diameter of the support section,

12.7 mm (1/2 inch) thick, and shall be attached to the bottom by 4.8 mm

(3/16 inch) continuous fillet welds.

H.4.6.14 Jet-nozzle mixers are not permitted.




Page 32 of 34

H.5 Openings and Appurtenances

H.5.2 Vents

H.5.2.1 Internal Floating Roof Pressure-Relieving Vents

H.5.2.1.1 (Exception) As a minimum, two overpressure/vacuum bleeder type vents

shall be installed in the internal floating roof. Vents shall be sized to

handle a total of 125% of the maximum filling/withdrawal rates that are

specified on the Storage Tank Data Sheet.

Commentary Note:

Bleeder vents shall be designed to open and close automatically when the roof is 75 mm (3 inch) above its low support legs position upon emptying and filling the tank, respectively.

H.5.2.2 Tank Circulation Vents

H5.2.2.1 (Exception) Peripheral circulation vents shall be located above the shell-

to-roof junction with an outward projecting hood with bottom air-intake

to minimize dust ingress.

H.5.2.2.3 (Exception) Pressure/vacuum venting devices shall provide protection

against overpressure/vacuum for normal conditions (resulting from

operational requirements and atmospheric changes) and emergency

conditions (resulting from exposure to an external fire) according to

API STD 2000.

H.5.2.3 Internal floating roofs shall be provided with overpressure/vacuum vents

for the floating condition in accordance with Appendix C (paragraph

C.3.9.2) of this specification.

H.5.5.3 Inspection Hatches

(Exception) Inspection hatches shall be located on the fixed roof to

permit visual inspection of the seal region.

H.5.6 Inlet Diffuser

(Exception) An inlet diffuser with slots shall be specified for tanks with

internal floating roofs with the following requirements:

1) Size of diffuser and number and dimensions of its slots shall

accommodate the maximum pumping-in rate.

2) Slots shall be located at 60 degrees (2 o'clock and 10 o'clock

positions) from the vertical centerline of the diffuser.




Page 33 of 34

H5.7 Gauging and Sampling Devices

(Exception) Internal floating roofs shall be provided with gauging and

sampling devices when specified by the Design Engineer.

H.6 Fabrication, Erection, Welding, Inspection, and Testing

H.6.4 (Exception) Floatation test and initial fill inspection shall be performed

by the erector and witnessed by the purchaser.

H.6.6 Initial Flotation

H.6.6.1 (Exception) Internal floating roofs in accordance with types H.2.2(c),

(d), and (e) shall be given a flotation test on water. During this test, the

roof and all accessible compartments shall be checked to confirm that

they are free from leaks. The appearance of a damp spot on the upper

side of the part in contact with the liquid shall be considered evidence of

leakage.

H.6.6.3 (Exception) Potable water having less than 50 ppm chlorides shall be

used for testing when the internal floating roof is constructed of

aluminum or stainless steel.

H.6.7 Internal floating roof components that are fabricated or attached by

welding, such as clips, gusset plates, etc., shall be completely seal-

welded.

H.6.8 Shop Fabrication

H.6.8.1 Straightening of material shall be done by pressing or other non-injurious

methods before the material is laid out or worked on in any way.

Materials shall not be hammered.

H.6.8.2 When the edges of plates are cut with a torch, the resulting surface shall

be uniform, smooth, and free from scale and slag before performing any

welding.

H.6.9 Shop Inspection and Testing

H.6.9.1 Internal floating roofs manufactured in accordance with this specification

are subject to verification by the Saudi Aramco Inspector in accordance

with Saudi Aramco Inspection Requirements Form 175-324900.

H.6.9.2 Inspection at the mill, shop, or fabrication yard shall not release the

manufacturer of the internal floating roof from responsibility for

repairing or replacing any defective material or workmanship that may





Page 34 of 34

be subsequently discovered in the field.

H.6.9.3 All support brackets that are welded to tubular pontoons shall be dye-

penetrant inspected.

H.6.9.4 Welded tubular pontoons shall be pneumatically pressure tested with air

at 35 kPa (5 psig) and the welds visually inspected by using a soapy

water solution or by immersing the pontoons under water. All defective

welds shall be repaired and the pontoons re-tested prior to shipment.

H.6.10 Installation

H.6.10.1 Internal floating roofs shall be installed by contractors who have been

approved by the manufacturer of the internal floating roofs.

H.6.10.2 Internal floating roofs shall be installed in accordance with the

procedures specified by the internal floating roof manufacturer.

H.7 Drawings and Calculations

The internal floating roof manufacturer shall prepare drawings,

calculations, and data in accordance with Form NMR-7918-2,

Nonmaterial Requirements. Drawings and calculations that are approved

by the Design Engineer shall not relieve the internal floating roof

manufacturer of the responsibility to comply with API STD 650 and this

specification.


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