Document77

PROJECT SPECIFICATION TAKREER

PROJECT No 5578

Agreement no 07-5578-F-1

RUWAIS REFINERY

EXPANSION PROJECT

COMPANY Doc. No. 5578-AMD-MF-003

ENG Doc. 25418-1000-3PS-MT00-M0003

Rev. 1

INTERNATIONAL BECHTEL CO. LTD.

THE DESIGN OR PART THEREOF CONTAINED IN THIS DOCUMENT WAS DEVELOPED FOR TAKREER FOR THE PROJECT AND REMAINS THE PROPERTY OF TAKREER. ALL

INTERNATIONAL BECHTEL CO. LTD. PROPRIETARY INFORMATION OR UNDERLYING INTELLECTUAL PROPERTY UTILIZED IN THE CREATION OF THE DESIGN OR INFORMATION

CONTAINED HEREIN SHALL REMAIN THE PROPERTY OF INTERNATIONAL BECHTEL CO. LTD..

ELECTRONIC DOCUMENTS, ONCE PRINTED, ARE NON-CONTROLLED AND MAY BECOME OUTDATED 25418-1000-3PS-MT00-M0003 Page 1 of 37

PROJECT SPECIFICATION FOR

FIELD ERECTED WELDED

STEEL STORAGE TANKS

(API 620)

RUWAIS REFINERY EXPANSION PROJECT

FRONT END ENGINEERING DESIGN

TAKREER

PROJECT SPECIFICATION


STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY

EXPANSION PROJECT COMPANY Doc. No. 5578-AMD-MF-003

ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1

ELECTRONIC DOCUMENTS, ONCE PRINTED, ARE NON-CONTROLLED AND MAY BECOME OUTDATED

25418-1000-3PS-MT00-M0003 Page 2 of 37

This page is a record of all revisions of this document. All previous issues are hereby

superseded and are to be destroyed.

NOTES:

Revisions after IFD are denoted as follows:

(a) By a vertical line in the right-hand margin against the revised text.

(b) By a triangle symbol for graphics, the revision number being denoted within the symbol.

Revision symbols are positioned adjacent to the revision.

(c) CHKD = Checked by, DISC = Discipline Lead, PEM = Project Engineer Manager,

PMC = Project Management Consultant.

APPROVED REV DATE

REASON

FOR ISSUE BY CHKD

DISC PEM PMC COMPANY

1 21-Oct-08 Issued For Feed KBS SK SK/GSS TSB

0 10-Sep-08 Issued For Approval KBS SK SK/GSS TSB

Signed (Initials)

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 3 of 37

PARAGRAPHS REVISED THIS ISSUE

Para. No. Para. No. Para. No. Para. No.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 4 of 37

TABLE OF CONTENTS

1.0 GENERAL .................................................................................................................................7

1.1 INTRODUCTION ......................................................................................................................7

1.2 PURPOSE ..................................................................................................................................7

1.3 DEFINITIONS ...........................................................................................................................7

1.4 SUBMITTALS............................................................................................................................8

2.0 CODES, AND STANDARDS...................................................................................................10

3.0 REFERENCE DOCUMENTS ..................................................................................................11

4.0 DOCUMENT PRECEDENCE..................................................................................................13

5.0 SPECIFICATION DEVIATION/CONCESSION CONTROL ...................................................13

6.0 QUALITY ASSURANCE/QUALITY CONTROL....................................................................13

7.0 DOCUMENTATION ................................................................................................................14

8.0 SUBCONTRACTORS/SUBVENDORS ...................................................................................14

9.0 HANDLING .............................................................................................................................15

9.1 PACKAGING AND SHIPPING................................................................................................15

10.0 DESIGN ...................................................................................................................................15

10.1 GENERAL ...............................................................................................................................15

10.2 STABILITY..............................................................................................................................15

10.3 CAPACITIES ...........................................................................................................................16

10.4 DESIGN OF SHELL, ROOFS AND BOTTOM........................................................................16

10.5 EXTERNAL LOADING...........................................................................................................16

10.6 ROOF DESIGN........................................................................................................................17

10.7 DESIGN DATA ........................................................................................................................18

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 5 of 37

11 MATERIALS............................................................................................................................19

11.1 GENERAL ...............................................................................................................................19

11.2 ADDITIONAL MATERIAL REQUIREMENTS.......................................................................19

11.3 CONSTRUCTION MATERIALS .............................................................................................19

11.4 NOTCH TOUGHNESS REQUIREMENTS..............................................................................21

11.5 MECHANICAL TESTING.......................................................................................................21

11.6 MATERIAL CERTIFICATES ...................................................................................................21

11.7 REINFORCING PLATES.........................................................................................................21

11.8 STRUCTURAL BOLTS ...........................................................................................................21

11.9 RECEIPT AND STORAGE OF MATERIALS..........................................................................22

11.10 PREPARATION OF MATERIALS ...........................................................................................22

11.11 MANUAL GAS CUTTING ......................................................................................................22

12 ERECTION ..............................................................................................................................22

12.1 ERECTION METHODS...........................................................................................................22

12.2 WIND BRACING (DURING ERECTION) ..............................................................................24

12.3 ERECTION HOLES AND ATTACHMENTS ...........................................................................24

12.4 SETTING OUT BOTTOM COURSE OF SHELL PLATES......................................................24

12.5 CHECKING OF ALIGNMENT................................................................................................24

12.6 ROOF FRAMING ....................................................................................................................25

12.7 SHELL TOLERANCES............................................................................................................25

13 FOUNDATIONS ......................................................................................................................26

13.1 CHECKING OF FOUNDATIONS............................................................................................26

13.2 ACCEPTANCE OF FOUNDATIONS.......................................................................................26

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 6 of 37

14 OPERATIONAL FITTINGS FOR VERTICAL TANKS............................................................27

14.1 RANGE OF FITTINGS AND ACCESSORIES.........................................................................27

14.2 DESIGN OF FITTINGS, MOUNTINGS AND ACCESSORIES...............................................31

15 WELDING AND FABRICATION ............................................................................................32

15.1 WELDING ...............................................................................................................................32

15.2 FABRICATION TOLERANCES ..............................................................................................32

15.3 TANK PARTS...........................................................................................................................32

16 INSPECTION...........................................................................................................................33

16.1 GENERAL ...............................................................................................................................34

16.2 SURVEYS ................................................................................................................................34

16.3 SECTIONING ..........................................................................................................................34

17 TANK TESTING......................................................................................................................34

17.1 TANK BOTTOMS....................................................................................................................34

17.2 TANK SHELLS........................................................................................................................35

17.3 TANK ROOFS..........................................................................................................................35

17.4 REPAIR OF LEAKS.................................................................................................................35

17.5 RETESTING ............................................................................................................................36

17.6 INITIAL FILLING ...................................................................................................................36

17.7 SAFETY PRECAUTIONS........................................................................................................36

18 CLEANING AND PAINTING..................................................................................................37

18.1 CLEANING..............................................................................................................................37

18.2 PAINTING AND/OR LINING..................................................................................................37

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 7 of 37

1.0 GENERAL

1.1 INTRODUCTION

This specification gives the minimum requirements for the fabrication, erection, and testing of

field erected vertical tanks in accordance with, and intended to fulfill all the requirements of API

Standard 620.

1.2 PURPOSE

This specification is intended to provide the minimum requirements to the tank VENDOR for

the design, fabrication, erection and testing of vertical tanks for the Project.

If national and/or local regulations exist in which some of the requirements may be more

stringent than in this Specification, the VENDOR shall determine by careful scrutiny which of

the requirements are the more stringent and which combination of requirements will be

acceptable as regards safety, environmental, economic and legal aspects. In all cases the

VENDOR shall inform the CONTRACTOR/COMPANY of any deviation from the

requirements of this Specification which is considered to be necessary in order to comply with

national and/or local regulations. The CONTRACTOR/COMPANY may then negotiate with

the Authorities concerned with the object of obtaining agreement to follow this specification as

closely as possible.

1.3 DEFINITIONS

For the purposes of this specification, the following definitions shall apply:

CONCESSION REQUEST - A deviation requested by the SUBCONTRACTOR or VENDOR,

usually after receiving the contract package or purchase order. Often, it refers to an authorization

to use, repair, recondition, reclaim, or release materials, components or equipment already in

progress or completely manufactured but which does not meet or comply with Takreer

requirements. A CONCESSION REQUEST is subject to COMPANY approval.

SHALL - Indicates a mandatory requirement.

SHOULD – Denotes an action or requirement which is not mandatory but which is strongly

recommended.

COMPANY - shall be defined as ABU DHABI OIL REFINING COMPANY (TAKREER)

CONTRACTOR - shall be defined as the organization to which TAKREER award the

Engineering, Procurement and Construction (EPC) phase.

MANUFACTURER/VENDOR - shall be defined as the supplier of equipment and support

services for a particular piece of equipment/package.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 8 of 37

SUB-CONTRACTOR - shall be defined as any person or persons, firm, partnership,

corporation or combination thereof engaged by CONTRACTOR (not being an employee of

CONTRACTOR) for supplying services to CONTRACTOR for the performance of services.

SUB-VENDOR - shall be defined as any supplier of equipment and support services for a

particular piece of equipment/package to a VENDOR.

1.4 SUBMITTALS

1.4.1 General

VENDOR’S drawings, calculations, and engineering data submitted to CONTRACTOR shall

be in the English language, refer also to Section 7.0.

1.4.2 Engineering Data Requirements

a. The VENDOR shall submit as a minimum the following engineering data for review by

CONTRACTOR:

• General arrangement and complete detail drawings as required for the fabrication of

each tank. A drawing index for each tank is required and shall be resubmitted each time

drawings are revised and reissued.

• Welding procedures (WPS) including procedure qualification record (PQR) and weld

maps.

• Heat treating procedures (if required)

• VENDOR’S design calculations.

b. Documents shall be in reproducible form and of micro filmable quality. VENDOR shall not

proceed with fabrication until notified by CONTRACTOR.

1.4.3 All subsequent revisions made by the VENDOR to the data listed in paragraph 1.4.2 shall be

resubmitted to CONTRACTOR for review.

1.4.4 CONTRACTOR reserves the right to review Certified Material Test Reports for all materials of

construction at any time during shop fabrication or field erection. VENDOR shall maintain these

documents readily available for such review and shall submit them to CONTRACTOR for final

record.

1.4.5 Review of the VENDOR’S documents by CONTRACTOR does not relieve the VENDOR of

responsibility of compliance with the applicable codes, standards, project drawings, and

specifications, or the accuracy of shop dimensions.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 9 of 37

1.4.6 Manufacturer’s Data Report

• As-built drawings

• Design calculations

• Radiography and NDE Reports

• Testing Reports

• Foundation Settlement Report

• Certificate of Compliance with API and this specification

• Welding Procedures and weld maps

• Material Certificates

• Name Plate to Comply with API

1.4.7 API Requirements

Upon completion of construction, provide CONTRACTOR with copies of the data sheets and a

MANUFACTURER’S Certification according to Appendix "M" of API-620, which reflects the

as-built conditions, certifying that the tank conforms to the requirements of this specification.

1.4.8 Tank VENDOR Responsibilities

a. Be responsible for complete design and construction of tanks in accordance with this

specification and other instructions furnished by the CONTRACTOR.

b. Ensure conformance to the latest Codes and legal requirements.

c. Establish tank dimensions to furnish the most economical design, unless otherwise specified.

In either case the VENDOR is encouraged to submit an alternate bid based on the most

economic design for evaluation purposes by CONTRACTOR/COMPANY.

d. Furnish and install all internals and accessories where applicable as detailed herein unless

otherwise specified on CONTRACTOR’S tank drawing.

e. Furnish complete test data and procedure including temperature limitations.

f. Furnish gauging tables in accordance with API Manual of Petroleum Measurement Standards

chapter 2 when required by CONTRACTOR’S Purchase Order. Otherwise calculated gauge

table shall be furnished.

g. Tank VENDOR shall furnish weights, material specification and thicknesses for all tanks with

his quotation.

h. The tank VENDOR shall furnish complete fabrication drawings to CONTRACTOR for

approval before starting fabrication. Each shop drawing shall be fully checked and signed as

checked before it will be accepted for approval.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 10 of 37

i. PROJECT drawings shall show the location of fittings.

j. VENDOR standard locations for fittings on floating roofs will be followed, unless other

instructions are given.

k. Internal and external Cathodic protection system as per tank data sheet.

l. Internal and external lining / painting (Refer Section 18) wherever specified in data sheet.

2.0 CODES, AND STANDARDS

It shall be the VENDOR’S responsibility to be, or to become, knowledgeable of the

requirements of the referenced Codes and Standards.

The following codes and standards shall, to the extent specified herein, form a part of this

specification. 15th January 2008 is the effective date for all codes and standards i.e. the code or

standard valid on that date shall be the one to be used.

American Petroleum Institute (API):

API Standard 620, 10th Edition, + Addendum, June 2004- Design and Construction of Large,

Welded, Low-Pressure Storage Tanks

API Standard 653, Appendix B - Evaluation of Tank Bottom Settlement

API Standard 2000 - Venting Atmospheric and Low-Pressure Storage Tanks, Non-Refrigerated and

Refrigerated

API MPMS 2.2A - Manual of Petroleum Measurement Standards Chapter-2.2A – Tank

Calibration. - Measurement and Calibration of Upright Cylindrical Tanks by the Manual Strapping

Method

API MPMS 2.2B - Manual of Petroleum Measurement Standards Chapter-2.2B – Tank Calibration.

- Calibration of Upright Cylindrical Tanks Using the Optical Reference Line Method

Federal National and Other Codes:

National Fire Protection Association Code No. 30 - Flammable and Combustible Liquids

American Society of Civil Engineers

Uniform Building Code

ASME/ANSI B 16.47 Large Diameter Steel Flanges

American National Standards Institute (ANSI):

ASME B1.1 - Unified Inch Screw Threads

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 11 of 37

ASME B16.5 - Pipe Flanges and Flanged Fittings

European Committee for Standardization (EN):

EN 10204 - Types of Inspection Documents - Metallic Products

International Organization for Standardization (ISO):

ISO 9001 – 2000 - Quality Management System Requirements

ISO 9004 – 2000 - Quality Management Guidelines for Performance Improvement System

ISO 19011 - Guidelines for Quality and/or Environmental System Auditing

3.0 REFERENCE DOCUMENTS

The following reference documents, to the extent specified herein, form a part of this

specification.

Project Standard Specifications:

Project Specifications Takreer Doc’t No. Specification Title

25418-0000-3PS-S000-C0001 5578-AMD-CU-002 Structural Engineering Design Criteria

25418-0000-3PS-SS01-C0001 5578-AMD-CU-020 Structural Steel Fabrication

25418-1000-3PS-MT00-M0001 5778-AMD-MF-001 Design Basis-Tanks

25418-0000-3PS-NN00-N014 5578-AMD-MN-001 Insulation

25418-1000-3PS-M000-M0007 5578-AMD-MU-012 Requirements for Manufacturing Data

Report For Non-pressure Vessel

Equipment

25418-1000-3PS-M000-M0011 5578-AMD-MU-013 Criticality Rating System

25418-1000-3PS-M000-M0008 5578-AMD-MU-014 Minimum Shop Inspection and Certification Requirements

25418-1000-3PS-H002-Y0001 5578-AMD-MU-200 Fire Protection Design Philosophy

25418-1000-3PS-H002-Y0002 5578-AMD-MU-201 Water Spray Fire Protection Systems

25418-1000-3PS-H002-Y0003 5578-AMD-MU-202 Foam Fire Protection Systems

25418-1000-3PS-NW00-N0003 5578-AMD-MW-003 Welding of Storage Tanks

25418-1000-3PS-NX00-N0001 5578-AMD-MX-001 External Painting

25418-1000-3PS-NX00-N0010 5578-AMD-MX-002 Galvanizing

25418-1000-3PS-NLLG-N0001 5578-AMD-MX-004 Internal Lining

25418-1000-3PS-N001-N0001 5578-AMD-MY-002 Cathodic Protection for on grade tank bottom and buried piping.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 12 of 37

25418-1000-3PS-MFA0-M0001 5578-AMD-MV-005 Side Entry Mixers for Storage Tanks

25418-1000-3PS-N001-N0004 5578-AMD-MY-007 Cathodic Protection of Internal surface of

tank

25418-1000-3PS-NW00-N0008 5578-AMD-MW-008 Metallic Materials.

25418-1000-3PS-NW00-N0004 5578-AMD-MW-004 Materials and Fabrication Requirements

for Carbon Steel Piping and Equipment in

Severe Service.

Project Standard Drawings:

Project Drawing Takreer Drawing No. Drawing Title

25418-1000-3SD-MV00-M0025 5578-STD-MD-B-040 Earthing Clips For, Tanks, Vessels, and Supporting Structures

25418-1000-3SD-MT00-M0001 5578-STD-MF-B-001 Handrails for Cone Roof Tanks

25418-1000-3SD-MT00-M0002 5578-STD-MF-B-004 Product Drain & Water Draw Off

25418-1000-3SD-MT00-M0019 5578-STD-MF-B-005 Floating Suctions for Vertical Tanks - 4 inch, 6 inch & 8 inch

25418-1000-3SD-MT00-M0020 5578-STD-MF-B-006 Typical Swing Pipe - 3 inch up to 20 inch

Equipment

25418-1000-3SD-MT00-M0021 5578-STD-MF-B-007 Typical Winches for Swing Pipes

25418-1000-3SD-MT00-M0003 5578-STD-MF-B-008 Spiral-Type Staircase Provided With Stair

Treads of Galvanized Grating

25418-1000-3SD-MT00-M0007 5578-STD-MF-B-012 Level Gauge Pole for Fixed Roof Tanks

(Execution for Custody Transfer)

25418-1000-3SD-MT00-M0008 5578-STD-MF-B-013 Combined Guide Pole/Level Gauge Pole

for Floating Roof Tanks (for Custody

Transfer)

25418-1000-3SD-MT00-M0010 5578-STD-MF-B-015 Vertical Ladder

25418-1000-3SD-MT00-M0012 5578-STD-MF-B-017 Level Gauge Pole for Fixed Roof Tanks (Non Custody Transfer)

25418-1000-3SD-MT00-M0013 5578-STD-MF-B-018 Nameplate with Bracket for Tanks

25418-1000-3SD-MT00-M0015 5578-STD-MF-B-021 Subsurface Foam Systems for Flammable

and Combustible Liquids

25418-1000-3SD-MT00-M0016 5578-STD-MF-B-022 Semi-subsurface Foam System for

Flammable and Combustible Liquids

25418-1000-3SD-MT00-M0018 5578-STD-MF-B-024 Methods Of Tank Erection

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 13 of 37

4.0 DOCUMENT PRECEDENCE

The VENDOR shall notify the CONTRACTOR of any apparent conflict between this

specification, the related data sheets, the Codes and Standards and any other specifications

noted herein. Resolution and/or interpretation precedence shall be obtained from the

CONTRACTOR in writing before proceeding with the design/manufacture.

In case of conflict, the order of precedence is:

A – Datasheets

B – Specification

C - Codes and Standards

D – Standard Drawings

5.0 SPECIFICATION DEVIATION/CONCESSION CONTROL

Any technical deviations to this specification and its attachments including, but not limited to, the

Data Sheets and Narrative Specifications shall be sought by the VENDOR only through

CONCESSION REQUEST format. CONCESSION REQUESTS require CONTRACTOR’S and

COMPANY'S review/approval, prior to the proposed technical changes being implemented.

Technical changes implemented prior to COMPANY approval are subject to rejection.

6.0 QUALITY ASSURANCE/QUALITY CONTROL

VENDOR’S proposed quality system shall fully satisfy all elements of ISO 9001 – 2000 and ISO

9004 – 2000 with due regard to ISO 19011. The quality system shall provide for the planned and

systematic control of all quality related activities performed during design, development,

production, installation or servicing (as appropriate to the given system).

Implementation of the system shall be in accordance with the Contractor’s Quality Manual and

Project Specific Quality Plan, which shall both together with all related/reference procedures be

submitted to COMPANY for review, comment and approval as required by purchase/contract

documents.

The Criticality Rating (CR) System outlined in Project Specification 5578-AMD-MU-013 shall be

used by CONTRACTOR or CONTRACTOR’S designee to develop the design checking levels and

minimum requirements for shop inspection, testing and material certification given in Project

Specification 5578-AMD-MU-014.

Field inspection of partial or fully field fabricated tanks shall be per API-620, and as agreed to by

CONTRACTOR/COMPANY and tank VENDOR.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 14 of 37

7.0 DOCUMENTATION

VENDOR shall submit the type and quantity of drawings and documentation for

CONTRACTOR’S authorization or information as listed in the individual Material Requisitions

and Purchase Orders/Subcontracts, refer also to Paragraph 1.4.

Mutual agreement on scheduled submittal of drawings and engineering data shall be an integral

part of any formal Purchase Order/Subcontract.

Comments made by CONTRACTOR on drawing submittal shall not relieve VENDOR or

SUBVENDORS of any responsibility in meeting the requirements of the specifications. Such

comments shall not be construed as permission to deviate from requirements of the Purchase Order

unless specific and mutual agreement is reached and confirmed in writing.

Each drawing shall be provided with a title block in the bottom right-hand corner incorporating the

following information:

1. Official trade name of the company.

2. VENDOR’S drawing number.

3. Drawing title giving the description of contents whereby the drawing can be identified.

4. A symbol or letter indicating the latest issue or revision.

5. PO number and item tag numbers.

Revisions to drawing shall be identified with symbols adjacent to the alterations, a brief description

in tabular form of each revision shall be given, and if applicable, the authority and date of the

revision shall be listed. The term "Latest Revision" shall not be used.

8.0 SUBCONTRACTORS/SUBVENDORS

The VENDOR shall assume unit responsibility and overall guarantee for the equipment package

and associated equipment.

The VENDOR shall transmit all relevant purchase order documents including specifications to his

SUBVENDORS and SUBCONTRACTORS.

It is the VENDOR’S responsibility to enforce all Purchase Order and Specification requirements on

his SUBVENDORS and SUBCONTRACTORS.

The VENDOR shall submit all relevant SUBVENDOR and SUBCONTRACTOR drawings and

engineering data to the CONTRACTOR.

The VENDOR shall obtain and transmit all SUBVENDOR and SUBCONTRACTOR warranties to

the CONTRACTOR/COMPANY, in addition to the system warranty.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 15 of 37

9.0 HANDLING

9.1 PACKAGING AND SHIPPING

Preparation for shipment of materials to the jobsite shall be in accordance with the VENDOR’S

standards and as noted herein. VENDOR shall be solely responsible for the adequacy of the

preparation for shipment provisions with respect to materials and application, and to provide

equipment at the destination in ex-works condition when handled by commercial carriers.

Adequate protection shall be provided to prevent mechanical damage and atmospheric corrosion in

transit and at the jobsite. High humidity, rain, dust, sand, salt air, and salt water are some of the

adverse conditions to be allowed for at the jobsite.

10.0 DESIGN

10.1 GENERAL

VENDOR shall design, fabricate, inspect, test, and certify tanks in accordance with API 620,

except where modified as specified. Obtain CONTRACTOR approval for deviations, exceptions,

and substitutions to API, including those that are permitted, subject to approval of

CONTRACTOR/COMPANY.

a. Corrosion allowance, when specified, shall be added to calculated shell and roof thicknesses

and minimum bottom plate thicknesses. The total thickness of shell or roof shall not be less

than the minimum permitted by API 620.

b. The provisions of NFPA No. 30, Flammable and Combustible Liquids Code, shall be complied

with in the tank design.

c. Vents shall be sized in accordance with API Standard 2000 unless otherwise specified.

d. All connections shall be flanged. Minimum nominal diameter shall be DN 50.

e. Flange bolt hole orientation for all tank nozzles including tangential and branch connections

shall straddle the natural tank centerlines.

f. Heating coil pipes (when specified) shall be of seamless quality with Schedule 80 as a

minimum and connected by butt welded joints. Heating coil supports shall not be welded to

tank bottom; however, they shall be rigidly supported.

10.2 STABILITY

For calculations of tank stability in strong winds and seismic events, the velocities and data given

in Structural Engineering Criteria 5578-AMD-CU-002 shall be used.

Unstable tanks shall be provided with anchor bolts and concrete foundation rings. Uplift is caused

by the internal vapor pressure acting against the underside of the roof, in conjunction with wind

load. A stability calculation shall be made to determine the number of anchor bolts required.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 16 of 37

10.3 CAPACITIES

10.3.1 Capacities specified for tanks are minimum net working capacities:

a. Total liquid capacity, nominal liquid capacity and volume of vapor space shall be as per API 620 Para

3.2 and 5.1.4.

10.4 DESIGN OF SHELL, ROOFS AND BOTTOM

Tank shell, roof and bottom shall be designed per API-620, Para. 5.10.

10.4.1 Limits for Shell Plate Thickness

a. The nominal/minimum thickness of the shell plates shall be as per API-620, Para.. 5.10.3 and

5.10.4.

b. No course shall have a thickness less than that of the course above, regardless of the material of

construction.

c. The vertical joints between shell plates shall not be in alignment within any three consecutive

courses, and the distance between vertical joints in adjacent courses shall be approximately

one-third of the plate length. If this is not possible, the distance between vertical joints in

adjacent courses shall not be less than 0.3 m.

10.4.2 Bottom Design

a. Bottom plates shall be at least 6 mm (1/4 in.) minimum thick exclusive of corrosion allowance

as per API-620, Para. 5.9.4.2.

b. Pad Plates

Pad plates fixed to the tank bottom shall be used at all supports and be continuously welded.

Pad plates should be of circular shape; if square or rectangular plates are used, they shall have

their corners rounded (radius at least 5 times the plate thickness).Reinforcement plate / pad for

a flush-type side wall connection shall confirm to API 620 Para 5.27.4.

c. All storage tank bottoms are to be cathodically protected against soil side corrosion per

specification 5578-AMD-MY-002.

NOTE: Tank VENDOR shall be aware of the test requirements to ensure that the cathodic

protection system has not been damaged or shorted during fabrication of the bottom

plates, per the above specification.

10.4.2 Compression Rings

Compression rings shall be designed as per API 620 Para 5.12.4 & 5.12.5.

10.5 EXTERNAL LOADING

10.5.1 Wind Girders

a. General

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 17 of 37

Tanks may require intermediate wind girders to maintain roundness over the full height of the

tank shell under wind load condition. The need for these wind girders and the required number

shall be calculated as indicated in API-620 Para 5.10.6.

b. Location of Wind Girders

The girders on the shell shall be located in accordance with API-620 Para 5.10.6, calculating

unstiffened height of shell.

In view of possible corrosion, which often occurs at the upper part of the tank shell, the girders

should be installed as high as permitted by the calculation results.

c. Design of Wind Girders

The minimum sizing for intermediate wind girders shall be per API-620 Para 5.10.6.6.

Continuous welds shall be used for all connections of secondary wind girders. Full penetration

butt welds shall be used for joining sections of the wind girder ring.

A mouse hole (20 mm radius) shall be made in the joining sections next to the tank shell to

prevent fusion between butt weld and tank shell.

10.5.2 Other Loadings

All other loadings as specified in API 620 Para 5.4 shall be considered during design of tank.

10.6 ROOF DESIGN

10.6.1 Supporting of Roof Plates

a) Design of roof shall meet all requirements of API 620 Para 5.12.

b) Lateral braces between outer bay rafters must be provided when unsymmetrical structural

shapes are used for rafters and the tanks are located in areas subject to earthquake. The bracing

must be adequately sized for the seismic zone specified, and shall not be less than the minimum

required per API Standard 620.

c) For tanks specified with cone roofs, VENDOR may propose an alternate for supplying

self-supporting dome or umbrella roof when feasible and more economical.

10.6.2 Roof Plates

a. Joining of Plates

Laps shall be arranged with the higher plates (i.e., those nearer the tank center) underneath the

lower plates, in order to avoid the risk of condensed moisture becoming trapped in the lap on

the underside of the roof. However, if the roof plates are welded on both the internal and

external laps the tank VENDOR may propose an alternate.

Roofs of tanks shall be welded on both the internal and external laps, to facilitate external

coating and internal lining, when an internal lining requirement is indicated on the PROJECT

tank data sheets.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 18 of 37

To prevent corrosion due to sand and salt buildups adjacent to welds on the top-side, a smooth

taper shall be built up with a compound such as an epoxy sealant before painting as specified in

specification 5578-AMD-MX-001.

10.7 DESIGN DATA

10.7.1 Wind Load

Wind design shall be in accordance with the American Society of Civil Engineers Code. Analysis

and interpretation of the Code shall be in accordance with Project Specification 5578-

AMD-CU-002, Structural Engineering Design Criteria.

10.7.2 Earthquake Load

Earthquake design for tanks shall be in accordance with the ASCE-7-05 code. Analysis and

interpretation of the code shall be in accordance with Project Specification 5578-AMD-CU-002,

Structural Engineering Design Criteria.

10.7.3 Design Climatic Conditions are as follows

Rainfall : 20 mm average per year

100 mm maximum per year

60 mm maximum for one hour period

Temperature : a. Winter: 5o C

Solar (Black Body): 87o C

b. Summer: 50o C

c. Minimum Design Metal Temperature: -15°C maximum

Snow load : - None

Maximum soil bearing pressure = 1.6 kg/cm2 (to be confirmed upon receipt of Project Soil

Report)

10.7.4 Units Of Measurement

QUANTITY UNIT ABBREVIATION

Area Square meter m2

Density kilograms per cubic meter kg/m3

Flow - Liquid cubic meter per hour m3/hr

Flow - Gas and Vapor normal cubic meter per Nm3/hr

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 19 of 37

hour

Force kilogram force kgf

Length Millimeter mm

Length Meter m

Mass Kilogram kg

Mass Ton te or t

Pressure - Design kilograms per square

centimeter gauge

kg/cm2 g*

Pressure - Operating kilograms for square

centimeter gauge

kg/cm2 g*

Temperature degree centigrade °C

Viscosity - Dynamic Centipoise cP

Volume Cubic meter m3

*kg/cm2 = gauge

11 MATERIALS

11.1 GENERAL

All materials shall conform with the requirements of API Standard 620 and 5578-AMD-MW-008.

Material for Severe service shall be in accordance with 5578-AMD-MW-004.

All materials of construction not specified on PROJECT drawings and material substitutions

equivalent to the ASTM materials specified in API Standards shall be approved by

CONTRACTOR/COMPANY before use. Tank VENDOR shall submit for approval complete

descriptions of the chemical and mechanical properties.

11.2 ADDITIONAL MATERIAL REQUIREMENTS

When medium high tensile steel, as defined in Para. 11.2.4, is used, additional requirements are

specified for weld details and weld inspection; see Welding of Storage Tank Specification 5578-

AMD-MW-003.

11.3 CONSTRUCTION MATERIALS

11.2.1 Bottom Plates and Roof Plates

A certificate from the steel mill in accordance with Para 11.6 is required to confirm that the steel is

made according to an ASTM specification allowable by this specification, and API-620. The steel

shall contain not more than 0.23% carbon content.

11.2.2 Shell Plates and Bottom Annular Plates

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 20 of 37

The steel shall contain not more than 0.23% carbon, 0.05% sulfur and 0.05% phosphorus, as

determined by ladle analysis.

The steel shall have a guaranteed minimum ultimate tensile strength of at least 363 N/mm2 and a

maximum ultimate tensile strength of not more than 510 N/mm2. The steel shall have a guaranteed

yield strength of at least 206 N/mm2. The steel shall have an elongation not less than 22%.

Mill certificates shall be supplied and shall indicate the steel making process as well as the

parameters stated in the material specification and this specification.

11.2.3 Specifications for Medium High Tensile Steel

Medium high tensile steels, as defined in Para. 11.2.4, may be used for the shells and bottom

annular plates of medium and large storage tanks (15,000 m3 capacity and over).

All steel shall be made by the basic oxygen or electric furnace process. Bessemer or Rimming

steels shall not be used.

11.2.4 Properties of Medium High Tensile Steel

For the purposes of this specification, steels are considered to be medium high tensile if they have a

guaranteed minimum yield strength in the range of 295-355 N/mm2 and a guaranteed ultimate

tensile strength in the range of 470-620 N/mm2.

The steel shall be fully killed and normalized to produce a fine grain structure. Semi-killed steel

may be used only for plates up to 16 mm in thickness.

The ratio of yield strength to tensile strength of the plates shall not exceed 0.85.

The steel shall have an elongation of not less than 22%.

11.2.5 Chemical Analysis of Medium High Tensile Steel

The ladle analysis of the steel shall comply with the following requirements:

C 0.23% max.

Mn 1.50% max.

Si 0.40% max.

P 0.04% max.

S 0.04% max.

P + S 0.07% max.

V 0.10% max.

Nb 0.04% max.

Nb + V 0.10% max.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 21 of 37

11.2.6 Carbon equivalent (for all welded components not in Severe Service)

Carbon content of carbon and carbon-manganese steels shall not exceed 0.23%, except for forgings

and castings, where this may be relaxed to 0.25%. For pressure containing components, the carbon

equivalents (CE) shall not exceed 0.43 given by:

15

Ni+Cu+

5

V+Mo+Cr+

6

Mn+C = C.E

11.4 NOTCH TOUGHNESS REQUIREMENTS

Notch toughness for shell plates, bottom annular plates, (etc.) shall be in accordance with API-620

Para 4.2.4.2 and 4.2.5. Toughness requirements for pipes, flanges and forgings shall be as per API

620 Para 4.3.5.

11.5 MECHANICAL TESTING

Mechanical testing for materials used in the construction of tanks shall be in accordance with API

Standard 620 and respective ASTM material standarad.

11.6 MATERIAL CERTIFICATES

VENDOR shall furnish material certificates in accordance with the requirements of EN10204

(formerly DIN 50049). The type of certificate required (‘2.1’, ‘2.2’, ‘3.1’ or ‘3.2’) is determined

by the inspection class assigned to the type of equipment or material. Component parts of a piece

of equipment may require different types of certificates. For specific requirements refer to the

individual material requisition and purchase order/subcontract.

Certificates shall show all the properties of materials guaranteed by its specification and any

additional requirements. They shall be submitted to the CONTRACTOR prior to commencement

of fabrication.

11.7 REINFORCING PLATES

Reinforcing plates shall be made from steel of the same quality as the shell plates to which they are

welded.

11.8 STRUCTURAL BOLTS

Except as specified in API 620, bolts shall be regular unfinished machine bolts with one heavy

semi-finished hex nut or studs with 2 nuts. Bolt and nut threads shall conform to ANSI B1.1

coarse, Class 2A and Class 2B respectively

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 22 of 37

11.9 RECEIPT AND STORAGE OF MATERIALS

The erection VENDOR shall inspect and keep stock of all materials delivered to site and be fully

responsible for their safekeeping. All fittings, valves, plates, etc., shall be properly laid out on

wooden supports clear of the soil. Special care shall be taken that damage does not occur to joint

faces of valves and flanges or to beveled ends of fittings.

11.10 PREPARATION OF MATERIALS

All materials shall be examined, cleaned and repaired as necessary at the site before being erected,

to ensure, that any damage incurred in transit is made good to the satisfaction of the

CONTRACTOR/COMPANY’S representative. Particular attention shall be paid to the removal of

buckles and distortions in the shell and bottom plates.

11.11 MANUAL GAS CUTTING

Manual gas cutting may be used for trimming the corners of bottom or roof plates where two

lapped joints intersect, and for cutting openings for fittings positioned on site.

Manual gas cutting shall not be used for any other purpose without the approval of

CONTRACTOR/COMPANY’S representative.

12 ERECTION

12.1 ERECTION METHODS

12.1.1 General

The main methods of erecting welded vertical tanks are outlined in this section and illustrated in

Project Standard Drawings (see Section 3.0).

Welded vertical tanks can be erected satisfactorily in several ways; no one particular system of

erection procedure is specified for use.

Erection VENDORS normally have a specific individual method, which they have adopted as the

result of experience, and have developed the erection technique most suitable for economical

working and good workmanship by their field crews.

Provided that the erection VENDOR employs a method which is known to give good results and

that the recommended sequences of erection and welding are followed, the method may be deemed

satisfactory.

To build tanks which are of sound quality, good appearance and free from excessive buckles or

distortion, correct welding sequences shall be adhered to and adequate supervision provided.

Therefore, to make certain that poor practices will not be followed and that care will be taken to

ensure satisfactory construction, VENDORS shall outline their method of erection for approval by

the CONTRACTOR/ COMPANY before a contract is placed. The main well-known methods of

erection are given below.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 23 of 37

12.1.2 Progressive Assembly And Welding

In the progressive assembly method, the bottom plates are assembled and welded first. Thereafter

the shell plates are erected, held in place, tacked and completely welded. This shall be done course

by course, working upwards to the top curb angle. No course shall be added as long as the

previous course has not been entirely welded.

The erection and completion of the roof framing and roof plates then follow. See Project Standard

Drawings (see Section 3.0).

12.1.3 Complete Assembly Followed by Welding of Horizontal Seams

In the complete assembly method, the bottom plates are assembled and welded first. Thereafter the

shell plates are erected, held in place, tacked and only the vertical seams completely welded,

leaving the horizontal seams un welded. This shall be done course by course, working upwards to

the top curb angle. No course shall be added as long as the vertical seams of the previous course

have not been entirely welded.

The erection and completion of the roof framing and roof plates then follow. Finally the horizontal

seams are welded, working upwards from the bottom course or downwards from the top curb

angle. See Project Standard Drawings (see Section 3.0).

12.1.4 Jacking-Up Method

Some VENDORS employ a system of erection in which the bottom plates are completed, the top

course is erected on the bottom plates, the roof framing and sheeting are completed and a number

of jacks are then assembled around the structure. By means of these jacks, the completed top

course together with the roof framing and sheeting is lifted to a height sufficient to insert the next

lower course. The jacking method and the supporting of the partly erected shell shall have no

adverse effect on the roundness of the shell.

The welding is completed at each stage of lift until all courses of the shell plates have been inserted

and the finished height is reached.

The final operation is the welding of the bottom course to the bottom plates. See Project Standard

Drawings (see Section 3.0.).

12.1.5 Prefabrication

For a hazardous location and/or close to existing tanks already storing light products, tanks can

be prefabricated and moved to their permanent site either by:

• Prefabrication of the tank in the workshop. The maximum dimensions depend on the

possibilities and limitations with respect to transport.

Generally this method shall be limited to tanks with diameters up to 12 meters.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 24 of 37

• Prefabrication of the tank on a temporary foundation at a safe location nearby. The

complete tank is then moved to its permanent foundation, e.g. by crane, on rollers or by

air cushion.

• The water test shall be carried out when the tank is standing on its permanent

foundation.

This method may only be used with the written agreement of the

CONTRACTOR/COMPANY.

12.2 WIND BRACING (DURING ERECTION)

During erection, tanks shall be safeguarded adequately against distortion or damage due to wind

pressure, by the provision of suitable steel wire guys or braces.

A minimum of one guy every 8 m of circumference is recommended.

These shall remain in place until welding of the shell plates and erection of the roof framing has

been completed, or, with open top tanks, until the wind girder has been completed.

Particular attention shall be given to the reliability of anchor blocks for the guys especially in weak,

muddy soils and due to soil settlement.

12.3 ERECTION HOLES AND ATTACHMENTS

Holes in plate work, to assist in erection, are not permitted.

Lugs, nuts, clamps, and other devices to assist in erection may be attached to the tank plates by

welding, but all such attachments required only for the purposes of erection shall ultimately be

removed and any noticeable projections of weld metal remaining shall be carefully ground away.

Plates shall not be gouged or torn in the process of removing attachments, and any indentations

caused thereby shall be filled with weld metal and ground flush with the plate surface.

Magnetic clamps, if used on the shell plates, shall be checked for residual magnetism and

demagnetized, if required.

12.4 SETTING OUT BOTTOM COURSE OF SHELL PLATES

In setting out the bottom course of shell plates, allowance shall be made for the contraction of the

vertical joints during welding. While the plates are being plumbed and checked for circularity, and

before they are tack-welded to the bottom, they shall be held in position by metal clamps or other

devices attached to the bottom plates.

12.5 CHECKING OF ALIGNMENT

Before final welding of the bottom course of shell plates begins, a check should be made to ensure

that the alignment of the plates and the width of the gaps between them are correct, and that any

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 25 of 37

inaccuracies after welding will be within the tolerances mentioned below. If the tolerances are

expected to be exceeded, the plates shall be realigned before final welding begins.

Care shall be taken to minimize lack of circularity or distortion between the top and bottom of the

tank shell, whether due to welding or any other cause. The CONTRACTOR/COMPANY reserves

the right to defer acceptance of any tank which shows shell plate buckling until the fault has been

rectified to the satisfaction of CONTRACTOR/COMPANY’S representative. Rectification by

cutting of shell plates is not permitted under any circumstances.

After the first course has been erected and welded, the internal radius, measured horizontally from

the center of the tank to any point on the inside of the tank shell, shall not vary from the nominal

internal radius by more than that specified in API-620 Para 6.5.

12.6 ROOF FRAMING

Before erection of the roof framing begins, the tank shell shall be carefully checked for uneven

settlement, and any misalignment of the top of the shell shall be corrected before the roof members

are positioned.

Temporary supports for the erection of the roof framing shall not be removed until the erection of

the main and secondary framing is complete.

With dome roofs, the temporary center support shall not be removed until radial rafters, purlins and

bracings are erected, completed and welded, and all roof sheets are tack-welded into position. The

positioning of the roof trusses shall be done very accurately to prevent misalignment.

When assembling roof sheets on the framing, excessive unsymmetrical loads shall be avoided and

not more than three roof sheets shall be stacked at any one point.

For dome roofs, the roof sheets shall be assembled symmetrically, working from the center

outwards.

The strength of erection poles used for temporary support of the roof structure shall be checked by

calculation for the maximum load to be carried.

In particular the resistance to buckling shall be checked. The erection VENDOR shall make a

calculation showing strength and safety of the erection poles to be used.

12.7 SHELL TOLERANCES

12.7.1 Verticality of the Tank Shell

After completion, the out-of-plumbness of the top of the shell relative to the bottom of the shell

shall not exceed 1/200 of the total tank height.

12.7.2 Local Deviations

Local deviations and tolerances from the Theoretical shape shall be in accordance with API-620

Para 6.5.4.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 26 of 37

Such departures from the design form shall be gradual over the gauge length, sharp changes in

form are not permitted.

12.7.3 Tolerances for Misalignment of Plates at Butt Welded Joints

a. Plates to be joined by butt welding shall be matched accurately and retained in position

during the welding operation. Matching of unequal thickness shall be as per API 620 Para

6.9, 6.13, 6.14 & 6.16.

13 FOUNDATIONS

13.1 CHECKING OF FOUNDATIONS

Before the start of erection, inspect each tank foundation to ensure that it is level and acceptable to

receive Work.

Tank erection and foundation tolerances shall be in accordance with API Standard 620, Para. 6.5.

Tank foundation shall meet requirement of API 620 Appendix – C.

Uneven foundation and settlement can result in the shell assuming an oval shape at the top,

particularly for floating roof tanks causing the floating roof to stick.

An indication a tank is settling unevenly is the appearance of gaps in the circumferential seams,

and departure of the shell from the perpendicular. If these signs appear, no attempt should be made

to close the gap by pulling with the key plates and wedges or cutting of plates.

The tank level should be checked and corrected by leveling of the foundation, if necessary. If the

gap is due to inaccurate fabrication, plate edges should be built up with weld metal, and the joint

welded. The weld built-up area shall receive radiographic testing after the welding is completed.

Pulling the plates to close the gap will cause deformations of the tank shell. To obtain a

perpendicular and circular shell, a level tank foundation is essential.

Tank foundations are usually finished off. Steel plates should be placed temporarily across the

edge of the tank foundation, in order to protect it while the bottom plates are being dragged into

position. Protection of foundation should also be provided even after bottom plates are dragged,

until completion of erection to handover.

13.2 ACCEPTANCE OF FOUNDATIONS

Before erection starts the VENDOR shall check the foundations of the tanks as regards height,

shape and level and will subsequently accept the base and take over responsibility for it.

This also includes the responsibility for its appearance and final shape after completion of the tank

erection, excluding the influence of soil settlement. If soil settlement is observed, the VENDOR

shall inform the CONTRACTOR/COMPANY immediately.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 27 of 37

The tank VENDOR should be made aware of the predicted soil settlements stated in the soil

investigation report.

13.3 CATHODIC PROTECTION OF TANK BOTTOM PLATES

Cathodic protection shall be utilized as a method of arresting corrosion on tank bottom plates in

conjunction with protective coatings.

It is critical that the tank VENDOR or SUBCONTRACTOR design procure and install the

impressed current cathodic protection anodes, reference electrodes, cables etc. During the

construction of the tank foundation and prior to the installation of the tank bottom. Tank bottom

cathodic protection system shall be designed in accordance with 5578-AMD-MY-002.

14 OPERATIONAL FITTINGS FOR VERTICAL TANKS

Unless otherwise specified on PROJECT tank drawings, tanks shall be provided with the standard

range of fittings and accessories as noted in this specification. Optional fittings shall be supplied

only when specified on the PROJECT tank drawings.

14.1 RANGE OF FITTINGS AND ACCESSORIES

14.1.1 Standard Range

VENDOR shall submit descriptive literature on all furnished accessories such as swing lines,

automatic tank gauges (when furnished by tank VENDOR) and rim seal with his quotation.

Unless otherwise specified on requisition, tanks shall be provided with the standard range of

fittings and accessories as listed on individual CONTRACTOR tank drawings/data sheets.

Optional fittings shall be supplied only when specified on the requisition.

For details of standard fittings and accessories, see applicable Standard Drawings.

For very high pumping rates or in other exceptional circumstances, it may be necessary to increase

the numbers or sizes of standard fittings, or to use special fittings or accessories (i.e. to carry out

in-tank blending). In such instances full supporting details should be included when ordering the

tank.

The numbers or sizes of fittings should not be reduced, since adherence to the specified range will

simplify the procurement of fittings, reduce delivery times, facilitate the fabrication erection of

tankage and ensure interchangeability.

Fittings such as breather valves, free vents and dip hatches may be to VENDOR’S designs if these

are accepted for use by the CONTRACTOR/COMPANY.

14.1.2 Breather Valves and Free Vents

The number and sizes of breather valves and free vents required should be specified separately due

to the large variations in pumping rates (per API-2000). The flow capacities of the breather valves

shall be based on data received from the valve Manufacturer.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 28 of 37

The maximum flow through a breather valve, when the pallet is fully open, occurs at a pressure

higher than that at which the valve pallet just commences to open, by an amount dependent on the

design of the valve and the weight of the pallet. The weight shall be adjusted so that the pallet is

fully open when the pressure just equals the pressure rating.

If the operating conditions of a tank are changed it shall be checked that the required venting

capacity does not exceed the available venting capacity of the breather valves or free vents.

14.1.3 Free Vents

All free vents if provided on tanks shall be screened. When deciding on the number of free vents

required, their capacity shall be taken at a pressure 0.0076 kg/cm2(g) and a vacuum of 0.0025

kg/cm2 (g).

14.1.4 Roof Nozzles

The flow characteristics of breather valves and free vents are influenced by the profile and length

of the roof nozzle. A tapered nozzle allows a higher flow through the valve than a straight nozzle.

This effect should be taken into account when calculating capacity ratings.

Wire netting in the openings of free vents and breather valves (i.e. as used to prevent nesting of

birds) shall have openings at least 6 mm square. Fine-mesh screens (i.e. as anti-flash protection)

should not be used because of the danger of blockage, especially under winter conditions.

14.1.5 Required Venting Capacity

The venting capacity required shall be determined in accordance with the rules specified in API

2000. These requirements shall be considered as minimum requirements.

The venting requirements shall include the following conditions:

• Inbreathing resulting from a maximum outflow of product from tank.

• Inbreathing resulting from contraction of vapors caused by a maximum decrease in

atmospheric temperature; see Para. 14.1.6.

• Outbreathing resulting from a maximum inflow of product into the tank and maximum

evaporation caused by such inflow.

• Outbreathing resulting from expansion and evaporation due to a maximum increase in

atmospheric temperature (thermal breathing).

• Outbreathing resulting from fire exposure.

NOTE: In addition to requirements of the current national and industry code (API 620), both

cone and dome shaped fixed roof tanks shall be designed to fail at the roof-to-shell

connection when subjected to an internal explosion. This is to be considered as a

primary item from a safety point of view, and is intended to eliminate further escalation

such as could result from failure mode at the shell-to-bottom connection.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 29 of 37

14.1.6 Thermal Venting

Special attention is required to the influence of a sudden drop in temperature (i.e. due to

rainfall) on the venting requirements of tanks containing warm product and for tanks in

tropical areas. A drop of 20o C or more in 15 minutes may be experienced. Where these

conditions apply the venting capacity shall be increased by at least 20% of the thermal venting

capacity requirements.

14.1.7 Stairways, Walkways, Platforms, Handrails, and Vertical Ladders

Stairways, landing platforms, ladders, and hand railing shall be provided as specified on Project

tank drawings. Stairways for tanks designed for insulated tanks, shall be double stringer type

supported by a minimum number of brackets.

a. Stairways, Walkways and Platforms

Stairways and walkways shall be designed in accordance with PROJECT Standard

Drawings (see Section 3.0).

Insulated tanks shall be provided with an offset stairway with stringers on both sides. The

offset shall be 25mm greater than the finished insulated thickness. Stairways on non-

insulated tanks shall be the two stringer type and stairway treads shall not be welded

directly to the tank shell.

Stairways and walkways shall be made of carbon steel grating. All grating shall be

galvanized serrated welded grating with 32 mm x 5 mm bearing bars at 30 mm centers and

cross bars at 100 mm centers. Grating material shall be in accordance with ASTM A569

and galvanized in accordance with Specification 5578-AMD-MX-002.

The minimum clear walking space on stairways and walkways shall be 600 mm.

The angle of stairways to the horizontal plane shall be 45o.

Stairway treads shall be galvanized serrated welded grating with 32 mm x 5 mm bearing

bars at 30 mm centers and cross bars at 100 mm centers with perforated or chequred plate

standard nosings. Stairs shall have a rise of 200 mm and treads shall have a minimum

width of 200 mm measured at the middle of the tread. A standard non slip nosing shall be

provided on the grating at the head of stairs

Spiral stairways shall be completely supported by the tank shell, and the ends of any

stringers or supports shall terminate clear of the tank foundation. Stair treads shall not be

welded directly to medium high tensile steel shells having a thickness of more than 12.5

mm.

Stairways and walkways shall be capable of supporting a moving concentrated load of

455 kg applied at any point.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 30 of 37

Walkways which extend from one tank to another tank or structure, or to the ground, shall

be supported in such a way as to permit free movement of the structures jointed by the

walkway, relative to each other and to the ground.

Spiral stairways for tanks with insulated shells shall be adapted to suit the type of insulation

used. Stair treads or stringers shall not penetrate the insulation.

b. Handrails

Handrails on tank roofs, stairways and walkways shall be designed in accordance with

PROJECT Standard drawings (see Section 3.0). The following requirements shall apply:

• Handrails shall be constructed from carbon steel tubular type.

• The distance between handrail uprights around the tank perimeter, on walkways, or

along the slope of stairways shall not exceed 2.4 m (96 in.).

• Handrails shall be provided on both sides of walkways and straight stairways, and

also on both sides of circumferential spiral stairways if the distance between the inner

stringer and the tank exceeds 200 mm.

• On all handrails the top rail and all uprights shall be capable of withstanding a load

of 91 kg applied at any point and in any direction at any point on the top rail.

• Safety handrails tubular type shall be provided around the roof of tank.

c. Vertical Ladders

Fixed vertical ladders shall be constructed of carbon steel and shall be completely supported

by the tank shell, with the ends of the runners terminating clear of the tank foundation.

Ladders exceeding 4.0 m in length shall be provided with safety cages (see Section 3.0).

14.1.8 Unless otherwise specified, the following shall be hot dip galvanized and/or painted in accordance

with PROJECT Specifications 5578-AMD-MX-002 and/or 5578-AMD-MX-001. Repair of

galvanizing and painting shall also be in accordance with the above specifications.

a. Spiral stair treads, stringer (if used), and stair railing.

b. Platforms (including supporting members) and handrails.

c. Ladders and cages.

d. Automatic tank gage elbows and pipe.

e. Wherever hot dip galvanizing is specified, either in this specification or on drawings, all

related bolting and detail hardware shall be galvanized.

14.1.9 Shell nozzle connections shall be API Standard 620 regular type unless otherwise specified.

Heating coil or heater nozzles shall be furnished with a 150 mm long internal projection beveled

for field welding whenever coil or heater is furnished by others.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 31 of 37

14.1.10 Grounding clips shall be provided in accordance with PROJECT Specification 5778-

AMD-MF-001.

14.1.11 VENDOR shall supply blind flanges, gaskets, and bolting (for other types of blanking covers as

may be required) necessary for testing. Supply covers for connections specified with service

covers remaining in place following tests. For connections not specified to be supplied with

service covers, the test covers shall be removed after testing.

14.2 DESIGN OF FITTINGS, MOUNTINGS AND ACCESSORIES

14.2.1 General

Tanks shall be provided with fittings and mountings as specified on the requisition. All tank fittings

and mountings shall be in accordance with the applicable standard detail drawings and any

additional requirements specified.

14.2.2 Flange Drilling

The flanges for all mountings up to and including 24 in. (600 mm) nominal pipe size, except shell

and roof manholes shall be made and drilled in accordance with ANSI B16.5. Flanges for nominal

pipe sizes over 24 in. (600 mm) shall be made and drilled in accordance with ASME/ANSI B

16.47, Series B.

14.2.3 Holding-Down Bolts

If holding-down bolts are included in the supply, they shall be fabricated as soon as possible after

approval of the relevant drawing by the company and be dispatched to the delivery point as defined

in the order.

Holding-down bolts are to be hot dip galvanized. The threads of the bolts and nuts shall be oiled at

installation.

14.2.4 Side-Entry Mixers

a. Both static and dynamic moments shall be checked by the tank CONTRACTOR, against the

appropriate design code, as well as static and dynamic stresses at the top edge of the reinforcing

pad. Deflections of the material just outside the mixer entry nozzle and around the reinforcing etc.

shall also be checked.

b. Minimum Clearance Between Propeller(s) and Tank Roof

For fixed roof tanks.

For fixed roof tanks the distance between the highest point of the propeller arc and the fixed roof

shall be not less than 2.5 m.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 32 of 37

c. Side entry mixers shall meet the requirements of specification, 5578-AMD-MV-005

15 WELDING AND FABRICATION

15.1 WELDING

15.1.1 Weld tanks in accordance with Welding Specification 5578-AMD-MW-003. Welding shall not

commence until VENDOR’S welding procedures have been approved by CONTRACTOR.

15.1.2 Locate vertical seams in bottom shell course a minimum of 300 mm (12 inches) away from bottom

annular ring radial weld seams.

15.1.3 Attach structural clips, handrail posts, and other components to the tank by welding with

continuous fillet welds.

15.1.4 Remove temporary erection attachments welded to the interior or exterior of the shell or to the

bottom by arc gouging, and grind weld area smooth.

15.1.5 The interior of tanks to be internally lined or coated must have all edges rounded to a minimum of

3 mm radius. Internal welds must be completely seal welded, ground smooth, and free from

surface porosity, pockets, and high spots. Remove weld spatter.

Additional surface preparation must be performed by VENDOR as specified on tank drawing

and/or as indicated in Lining Specification 5578-AMD-MX-004.

VENDOR shall also be aware that fabrication and layout of the bottom plates may be dependent on

the lining manufacturers requirements.

15.1.6 Butt welded shell seams must be located to avoid openings. If the location of connections or

attachments established by CONTRACTOR does not permit adequate clearance, consult

CONTRACTOR for a decision.

15.2 FABRICATION TOLERANCES

15.2.1 Tank erection and foundation tolerances must be in accordance with API-620 and as indicated in

this specification:

15.2.2 Install tank nozzles (excluding manholes) within the following tolerances:

a. Projection from outside of tank shell to extreme face of flange - plus or minus 5 mm.

b. Elevation or radial location - plus or minus 6 mm.

NOTE 1) Fabrication of tank shall also meet requirement of API 620 Section – 6.

2) Inspection, examination and testing of tank shall also meet requirement of API 620

Section – 7.

15.3 TANK PARTS

15.3.1 Plate Edge Preparation

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 33 of 37

a. General

The edges of plates may be sheared, machined, or cut with a machine-operated gas torch.

Shearing shall be limited to plates 10 mm or less in thickness.

When the edges of plates are cut with a torch the resulting surface shall be uniform and smooth

and shall be free from scale and slag accumulations before welding. A remaining fine film of

rust adhering to cut or sheared edges after wire brushing need not be removed before welding.

Curved edges of roof and bottom sketch plates and bottom annular plates shall be cut to shape

in the workshop by mechanized gas cutting or machining.

Plate thickness greater than 25mm shall be preheated prior to flame cutting.

b. Plate Edge Joints for Shell Plates

Recommended plate edge joints for hand welding are as follows:

• Vertical joints

Open-gap square butt joints may be used only for plate thicknesses of 6 mm and full

penetration welds are required.

Single-V butt joints shall not be used for plate thicknesses exceeding 13 mm.

Double-V butt joints shall not be used for plate thicknesses < 8 mm and shall be used

for plate thicknesses over 13 mm.

• Horizontal joints

Open-gap square butt joints may be used only where the thickness of the thinner plate

does not exceed 8 mm and full penetration welds are required.

Single-bevel butt joints may be used for plate thicknesses up to 8 mm and shall be used

where the thickness of the thinner plate exceeds 8 mm but does not exceed 13 mm.

Double-bevel butt joints may be used for plate thicknesses over 6 mm and shall be used

for plate thicknesses exceeding 13 mm.

15.3.2 Plate Tolerances

The profile of all shell plates shall be in accordance with API-Standard 620.

15.3.3 Rolling and Pressing

All shell plates shall be rolled to the correct tank curvature. Shell plates for tanks smaller than

25 m diameter shall have their ends pre-set to the proper curvature.

16 INSPECTION

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 34 of 37

16.1 GENERAL

Tanks shall be inspected in accordance with API Standard 620, and as outlined in this

specification.

The COMPANY/CONTRACTOR’S representative shall at all times have free access to all

parts of the site while the work covered by the contract is in progress.

The tank erection VENDOR shall afford the representative all reasonable facilities for ensuring

that the work is being carried out in accordance with the requirements of this specification.

16.2 SURVEYS

Upon completion of welding of the first course shell plates and prior to erection of the second

course, a survey of levelness, circularity, and plumbness shall be performed by the VENDOR.

Measurements shall be taken adjacent to and midpoint between each vertical weld seam. The

locations shall be clearly marked and identified with reference number, and shall be used for

any subsequent surveys as well as the final survey.

During the course of tank erection, additional surveys shall be performed as deemed necessary

by the VENDOR.

A final survey shall be performed by the VENDOR after all roof framing has been installed.

VENDOR shall submit the results to CONTRACTOR immediately after each survey has been

completed.

16.3 SECTIONING

Sectioning is not permitted on tank shell welds. Spot radiography shall be used in lieu of

sectioning.

17 TANK TESTING

Tanks shall be tested in accordance with API Standard 620.

17.1 TANK BOTTOMS

After welding of the bottom plates of storage tank has been completed, all welds shall be tested to

ensure that the tank bottom is free from leaks. This can be done by using a vacuum box, which

enables any leaks in the seams to be positively located by visual examination.

The test shall preferably be made as soon as possible after welding of the bottom, removal of slag,

and wire brushing, but before any surface coating is applied. The bottom plates shall in any case be

tested before water is let into the tank for hydrostatic testing.

The vacuum box is fitted with a glass viewing panel on its top and has an open bottom, around

which a continuous rubber seal and former are secured. The seal forms an airtight joint around the

section of the weld to be tested when the box is pressed against the bottom plates.

A partial vacuum can be created by means of a hand or motor-driven vacuum pump. A vacuum

gauge is incorporated in the box which has two connections: one is the suction tap fitted with a

non-return valve; the other is a vacuum release valve.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 35 of 37

For the detection of leaks, soap suds or some alternative substance shall be applied to all joints.

After jacking-up of a tank for re-leveling, the tank bottom shall again be tested for leaks.

17.2 TANK SHELLS

The shells of fixed roof tanks shall be tested after completion of the roof.

For fixed roof tanks, testing shall be done by filling the tanks with fresh water to the level of the

top leg of the top curb angle, and noting any leaks over a period of at least 24 hours.

For hydro testing of storage tanks, seawater may have to be used. Where seawater is used,

corrosion inhibitors shall be used to limit corrosion and will be subject to agreement with

COMPANY/CONTRACTOR. In addition, the method of hydro testing tanks greater than 90

meters in diameter shall be subject to the agreement of COMPANY/CONTRACTOR at the time of

enquiry.

Any tank showing evidence of leakage from the bottom during test must be emptied immediately.

The source of leakage must be determined and the defect repaired prior to refilling.

Unless otherwise agreed, the CONTRACTOR/COMPANY shall provide, install and remove all

pumps, water and water lines temporarily required for the testing of the tanks. All shell openings

shall be closed with blind flanges by the erection VENDOR.

17.2.1 The hydro test shall be performed using clean water or sea water and held for 48 hours maximum,

and draining shall start immediately after test is completed. If leaving test water in the tank(s) for

longer time periods is proposed, inhibitors and/or temporary impressed current cathodic protection

shall be used and a detailed plan shall be submitted to CONTRACTOR/COMPANY for approval.

Hydro test water shall be potable water with chloride level less than 30ppm, or inhibited sea water.

17.3 TANK ROOFS

Upon completion, the tank roof shall be tested in accordance with API-620 Section – 7. The

influence of sudden barometric changes and possible condensation during the night shall be

considered.

For the detection of leaks, soap suds or some alternative substance shall be applied to all joints.

Alternatively, the roof weld seams may be tested by the vacuum box method.

17.4 REPAIR OF LEAKS

All leaks detected during testing shall be repaired to the satisfaction of CONTRACTOR’S

representative, and on completion the entire tank shall be tight and free from leaks.

In the joints between shell plates or bottom plates, or both, the defective part shall first be cut out

and repaired by welding.

When the tank is filled with water for testing, defects in the shell joints shall be repaired with the

water level at least 0.3 m below the work.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 36 of 37

17.5 RETESTING

After all defects have been repaired the repaired welds shall be retested by the methods previously

described.

If further leaks are discovered when the tank is first filled with product, repairs shall not be made

until the tank has been rendered safe in accordance with Paragraph 17.7.

17.6 INITIAL FILLING

The initial filling of a tank with water, shall be done slowly and a continuous inspection shall be

maintained for the whole of the filling period, especially with a floating roof tank. The filling

procedure shall be established taking soil conditions into account. The filling procedure shall be

described in detail in a specification agreed by the soil mechanics specialist and shall be followed

strictly.

The VENDOR shall perform the hydro test in strict accordance with the procedures outlined in the

“Soils Report.” Due to the soil conditions, differential tank settlement may require jacking of the

tank after hydro test to re-level the tank. Evaluation of the settlement shall be in accordance with

API 620, Section-7. Vendor shall take jacking and leveling into consideration for the tank design.

Uneven settlement of the tank on its foundation shall be reported immediately to

CONTRACTOR/COMPANY’S representative, and filling shall be stopped at any signs of

excessive settlement pending a decision by CONTRACTOR/COMPANY’S representative on the

action to be taken.

In the case of excessive soil settlement, the situation shall be reported to the soil mechanics

specialist and his recommendations considered.

The temperature of the test water shall be not lower than that specified by API 620 for the

conditions concerned.

17.7 SAFETY PRECAUTIONS

The following safety precautions shall be taken:

A product connection shall not be made to any tank for any purpose until the tank is accepted to be

filled with product by CONTRACTOR/COMPANY’S representative.

Once product connections have been made to a tank, welding or other hot work shall not be carried

out until all lines connected to the tank have been disconnected, the open ends of the pipelines

blanked off, and the tank and its vicinity tested and rendered safe to the satisfaction of

CONTRACTOR/ COMPANY’S representative.

Once a tank has contained product, welding or other hot-work is prohibited before, in addition to

the requirements above, the tank has been completely emptied and rendered safe in accordance

with the local safety regulations, and written authority for the work has been issued by

CONTRACTOR/ COMPANY’S representative.

Roof manholes shall be open while filling or emptying a fixed roof tank for test purposes, so that

the tank is not damaged by excessive vacuum or pressure loading.

TAKREER



STEEL STORAGE TANKS

(API 620)

TAKREER

PROJECT No 5578


RUWAIS REFINERY


ENG Doc. 25418-1000-3PS-MT00-M0003 Rev.1


25418-1000-3PS-MT00-M0003 Page 37 of 37

18 CLEANING AND PAINTING

18.1 CLEANING

In addition to the general cleaning requirements of API Standard 620, the tank VENDOR shall

thoroughly broom sweep and wash clean the inside of each tank. Tank VENDOR shall also

remove all weld slag, loose scale, oil, dirt, sand, debris, and rubbish. Fresh water to be used for

washing and sea water for hydro testing.

18.2 PAINTING AND/OR LINING

Surface preparation and painting shall be in accordance with Specification 5578-AMD-MX-001,

and/or Lining Specification 5578-AMD-MX-004 unless specifically stated otherwise.

All tank plate surfaces shall be shop primed and painted in accordance with the Painting

specification.

Bottom plates shall be 100% coated on the underside in accordance with Painting Specification

5578-AMD-MX-001.

Tanks that are internally lined shall have attachments added to the roof to support hanging

scaffolding to be used during the lining operation. VENDOR to submit details to

CONTRACTOR/COMPANY for approval.

The requisition or order shall state for each tank the treatment/painting and or lining required for

that specific tank.