Specification for Shop Welded Tanks for Storage of Production Liquids

API SPECIFICATION 12F

TWELFTH EDITION, OCTOBER 2008 EFFECTIVE DATE: APRIL 1, 2009

Specification for Shop Welded Tanks for Storage of Production Liquids

Upstream Segment

API SPECIFICATION 12F

TWELFTH EDITION, OCTOBER 2008 EFFECTIVE DATE: APRIL 1, 2009

Special Notes

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Neither API nor any of API's employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of API's employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.

Classified areas may vary depending on the location, conditions, equipment, and substances involved in any given situation. Users of this specification should consult with the appropriate authorities having jurisdiction.

Users of this specification should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.

API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.

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All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.

Copyright © 2008 American Petroleum Institute

Foreword

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.

Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.

Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, D.C. 20005, standards@api.org.

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Contents

Page

1. Scope 1

   1. General 1

   2. Compliance 1

2. References 1

3. Definitions 2

4. Material 3

   1. General 3

   2. Plates 3

   3. Sheets 3

   4. Welding Electrodes 3

   5. Structural Shapes 3

   6. Piping 3

   7. Flanges 3

   8. Couplings 3

   9. Bolting 3

5. Design 4

   1. General 4

   2. Joint Design Definitions 4

   3. Size of Weld 4

   4. Joint Restrictions 4

   5. Size 4

   6. Bottom Type Design 4

   7. Thickness 5

   8. Joints in Bottom Plates 5

   9. Shell Attachments 5

   10. Shell Thickness Design 5

   11. Shell Joints 7

   12. Deck Type Design 7

   13. Thickness 7

   14. Deck Joints 7

   15. Shell Attachment 8

   16. Cleanout Design 8

   17. Connections Design8

   18. Anti-channel Drain Baffle Design 8

   19. Downcomer Pipe 8

6. Venting Requirements 9

   1. Normal Venting 9

   2. Emergency Venting 9

7. Fabrication, Testing, and Painting 10

   1. Fabrication 10

   2. Welding 10

   3. Testing 10

   4. External Painting 10

   5. Internal Coating 10

8. Marking 11

   Page

9. Inspection and Rejection 11

   1. Inspection Notice 11

   2. Inspection by Purchaser 11

   3. Rejection 11

   4. Compliance 12

Annex A (normative) Specification for Tank Bolting 13

Annex B (informative) Recommended Practice for Normal Venting 15

Annex C (informative) Recommended Relieving Capacities 17

Annex D (normative) Walkways, Stairways, and Ladders 19

Annex E (informative) Suggestions for Ordering Shop Welded Tanks 21

Annex F (informative) Use of the API Monogram by Licensees 23

Figures

1. Tank Dimensions 6

2. Type A (Unskirted) Cone Bottom 7

3. Type B (Skirted) Cone Bottom 7

4. 24-in.  36-in. Extended-neck Cleanout 9

5. Nameplate Format 11

Tables

1 Tank Dimensions 5

B-1 Venting Capacity Requirements 15

1. Emergency Venting Requirements 17

2. Calculated Venting Capacity of 8-in. Round Thief Hatch 18

Specification for Shop Welded Tanks for Storage of Production Liquids

1. Scope

   1. General

      
      

      This specification covers material, design, fabrication, and testing requirements for shop-fabricated vertical, cylindrical, aboveground, closed top, welded steel storage tanks in various standard sizes and capacities for internal pressures approximately atmospheric, not to exceed those listed in Table 1, Column 2.

      
      

      This specification is designed to provide the oil production industry with tanks of adequate safety and reasonable economy for use in the storage of crude petroleum and other liquids commonly handled and stored by the production segment of the industry. This specification is for the convenience of purchasers and manufacturers in ordering and fabricating tanks.

      
      

   2. Compliance

      
      

      The manufacturer is responsible for complying with all of the provisions of this specification. The purchaser may make any investigation necessary to be satisfied of this compliance by the manufacturer and may reject any material that does not comply with this specification. It is urged that the purchaser avail him/herself of this right and furnish his/her own inspection independently of any supervisory inspection furnished by the manufacturer, and that the purchaser’s inspector follow closely all the details of shop fabrication and/or field construction and testing herein specified which affect the integrity and safety of the completed structure.

      
      

2. References

API Specification 5L, Specification for Line Pipe

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

ASME B1.1 1, Unified Inch Screw Threads (UN and UNR Thread Form)

ASME B16.5, Pipe Flanges and Flanged Fittings

ASME B16.11, Forged Steel Fittings, Socket-Welding and Threaded ASME B18.2.1, Square and Hex Bolts and Screws, Inch Series ASME B18.2.2, Square and Hex Nuts

ASME B31.1, Process Piping

ASME Boiler and Pressure Vessel Code, Section IX—Welding and Brazing Qualifications

ASTM A36 2, Standard Specification for Carbon Structural Steel

ASTM A53, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

ASTM A106, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service

1. ASME International, 3 Park Avenue, New York, New York 10016, www.asme.org.

2. ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428, www.astm.org.

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