_1_weldsteeltanks

WELDED STEELTANKS

BUILDINGSPECIFICATIONS

Date: August 1996 Revision: 3 Page: 0

BUILDING

SPECIFICATION

WELDED STEEL-TANKS

WELDED STEELTANKS



Contents

1. Area of application

2. Other valid standards and documents

3. Foundation

4. Materials

5. Calculations

6. Drawings

7. Construction

8. Testing of welding connections

9. Permissible deviation in dimensions after fitting

10. Leak test and measurements of tank settling

11. Final inspections

12. Calibration

13. Painting

14. Execution of the work

WELDED STEELTANKS



1. Area of Application

This building specification is valid for "aboveground vertical cylindric welded steelconstructions" for all countries. Respective regulations (latest editions) have to beapplied such as DIN 4119, API 650, BS 2654 etc. with agreement of OT and dependingon the local regulations of the country where new tanks will be constructed. Thefollowing statements/regulations are to be considered in this sense. The buildingspecification entails additional demands and instructions to regulations by theauthorities and generally recognized technical regulations of the technique, whichmaintain their validity. In each case the latest editions of the regulations, collection ofrules and standards apply.Deviations in the execution are subject to approval by Oiltanking and possibly of theauthorities.

2. Other valid Standards and Documents

In addition to the guide lines layed out in the referenced standards all other relevantregulations and standards are to be considered. Details are shown on the data sheets.

3. Foundation

Laying the foundation is usually not part of the order of the tank manufacturer. Thedevelopment of the foundation can be taken from the data sheets. The foundationsurface is available with tolerances according to standards. Before the fitting of the tankis started levelling has to be carried out in the presence of the foundation manufacturerand the tank manufacturer, and a report has to be made. The tank manufacturer has toapprove the foundations.

4. Materials

For the materials to be used, thickness limitations, proof of quality and labelling thestipulations of the standards as well as local regulations are valid.

5. Calculations

For the calculation the standard as shown in the respective data sheets shall apply (API650, BS 2654, DIN 4119 etc.).Lay-out data can be taken from the data sheets. The calculations shall be available freeof charge in the required amount, however, at least 5 sets. If not particularly mentioned,corrosion allowances are not to be charged.

WELDED STEELTANKS



6. Drawings

All drawings shall be sent as blueprint in duplicate to Oiltanking for checking, one copystamped with the sign of approval will be sent back to the contractor. All final drawingsshall be sent to Oiltanking as blueprint in duplicate (A3 size). All drawings shall furtherbe submitted as "micro films" with drawing index.

Furthermore all documents shall be sent, such as certificates, building approvals, finalinspection reports, etc. Checking of drawings by qualified engineers is the responsibilityof the contractor or otherwise agreed.

This tankbook must be presented to Oiltanking for review before final submission.For the calibration of the tank the calibration authority requires the pattern of certaindrawings. These drawings shall be made available free of charge in duplicates asblueprint by the contractor after consultation with Oiltanking. Equally all drawingsrequired by the authorities third party inspection companies, etc. shall be delivered freeof charge.

One month before the construction is started the contractor shall submit to Oiltanking adelivery/construction/manpower and equipment schedule in triplicate.

This schedule must include supply and delivery dates of steel, construction andequipment parts as well as internal inspection dates up to the date of clearing of thebuilding site.

In the case of delays and changes an updated schedule is to be submitted automaticallyto Oiltanking at fortnightly intervals.

7. Construction

Basically the rules of the standards as well as subsequent standards and regulationsapply.

The demands and recommendations for the prefabrication and final fitting shall beobserved.

For the execution and the quality assurance of welding work the international standardsor the standards stipulated by the control firms/authorities are valid. For the weldingprocedures to be applied procedure tests acccording to the rules are to be submitted.The original welder certificates have to be submitted before work is started.

Certificates on the admission as specialised firms or objects of reference respectivelyhave to be submitted on demand.

WELDED STEELTANKS



8. Testing of Welding Connections

For the type and extent of testing of welding connections as well as working tests oncourse (rings) the stipulations of the tank buildings standards are valid.

9. Permissible Deviations in Dimensions after Fitting

The permissible tolerances of the standards for bottom, shell and roof are to bemaintained.

10. Leak Test and Measurement of Tank Settlement

Before filling the tank with water or the individual course respectively (in the case of wetconstruction) all tests regarding the materials and welding seams have to be concluded.A schedule is to be set up for the filling operation considering the settling to beexpected. Before and during filling, measurements of settling shall be carried out (edgeand center settlement), and shall be reported on the forms attached. All scheduled leaktests and operational tests of equipment parts shall be carried out and are part of theorder of the tank manufacturer. Before and after hydrotesting, all bottom welds have tobe checked 100% with vacuum box test.

11. Final Inspections

After completion of the tank a final inspection through the control office or the institutionstipulated through the building permission (corresponding to the country) has to takeplace.

12. Calibration

Calibration is part of the contractor's order, unless otherwise agreed.

13. Painting

Painting is not part of the contractor's order, unless otherwise agreed.

WELDED STEELTANKS



14. Execution of the Work

The work has to be carried out according to the drawings enclosed. Deviations thereofhave to be approved by Oiltanking. In each case the latest editions of the applicablestandards and accident prevention-regulations are to be considered.

Notes

a. During hydrotesting with seawater, a corrosion inhibitor shall be used as advisedby Oiltanking, for example Sodiumsulfite not less than 60 ppm of tank capacity.

b. For primary seals, a pantograph/spring type seal with steel sliding shoe (seal ring)and liquid mounted seal is required. Secondary seals upon request of Oiltanking(see data sheet tanks). Material of seals has to be 100% aromatic resistent.

c. Firefighting equipment shall be from recommended manufacturers. Oiltankingapproval has to be obtained prior to contractor's purchase order.

d. All welded connections such as but not limited to wind girders, pipe supports, foamdams, platforms, hand rails etc. shall be seal welded to avoid corrosion.