Specification for Shop-welded Tanks for Storage of Production Liquids

API SPECIFICATION 12F

THIRTEENTH EDITION, JANUARY 2019

API MONOGRAM PROGRAM EFFECTIVE DATE: JULY 2019

Special Notes

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Copyright © 2019 American Petroleum Institute

Foreword

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• the term “shall” denotes a minimum requirement in order to conform to the standard;

  
  

• the term “should” denotes a recommendation or that which is advised but not required in order to conform to the standard;

  
  

• the term “may” is used to express permission or a provision that is optional;

  
  

• the term “can” is used to express possibility or capability.

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Contents

Page

1. Scope 1

   1. General 1

   2. Compliance 1

2. Normative References 1

3. Terms and Definitions 3

4. Materials 4

   1. General 4

   2. Plates 5

   3. Sheets 5

   4. Welding Electrodes 5

   5. Structural Shapes 5

   6. Piping 5

   7. Flanges 5

   8. Couplings 6

   9. Bolting 6

5. Design 6

   1. Loads 6

   2. Load Combinations 6

   3. Tank Uplift 6

   4. Other Design Conditions 6

   5. Joint Design 7

   6. Tank Dimensions 7

   7. Bottom Design 7

   8. Shell Design 8

   9. Roof Design 8

   10. Floating Roof 11

   11. Appurtenance Designs 12

6. Venting Requirements 15

   1. Normal Venting 15

   2. Venting Due to Upset Conditions 15

   3. Emergency Venting 15

   4. Combination Gauge Hatch-Pressure/Vacuum Relief Valve (Gauging Port) 15

7. Fabrication, Testing, and Painting. 15

   1. Fabrication 15

   2. Welding 15

   3. Testing 15

   4. External Painting 16

   5. Internal Coating 16

8. Markings 16

9. Inspection and Rejection 17

   1. Inspection Notice 17

   2. Inspection 17

   3. Rejection 17

Contents

Page

Annex A (informative) API Monogram Program—Use of API Monogram by Licensees 18

Annex B (normative) Walkways, Platforms, Stairways, and Ladders 22

Annex C (informative) Suggestions for Ordering 26

Figures

1. Tank Dimensions 10

2. Type A (Unskirted) Cone Bottom 11

3. Type B (Skirted) Cone Bottom 11

4. Top Angle Detail 12

5. 24” Wide x 36” High Cleanout 13

6. Detail of Shell Plate Opening 14

7. Suggested Nameplate Format 17

Tables

1 Tank Dimensions 9

Specification for Shop-welded Tanks for Storage of Production Liquids

1. Scope

   
   

   1. General

      
      

      1. This specification covers material, design, fabrication, and testing requirements for new shop-fabricated vertical, cylindrical, aboveground, welded steel storage tanks in the standard sizes and capacities, and for internal pressures approximately atmospheric, given in Table 1.

         
         

      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.

         
         

      3. Only tanks built to the requirements stated in this specification may be identified as 12F tanks. Tanks built to dimensions other than listed in Table 1 are outside the scope of this specification.

         
         

      4. This specification has requirements given in two alternate systems of units. The manufacturer shall comply with the US Customary (USC) units. The SI unit equivalent is provided for convenience.

NOTE Per API document style, SI unit values appear first, followed by their USC equivalents in parentheses.

1. Compliance

   
   

   1. The manufacturer is responsible for complying with all the provisions of this specification. The purchaser may make any investigation necessary to satisfy himself or herself of manufacturer compliance and may reject any material that does not comply with this specification. The purchaser may wish to avail himself or herself of this right and furnish their own inspection independently of any supervisory inspection furnished by the manufacturer.

      
      

   2. This specification is not intended to cover storage tanks that are to be erected in areas subject to regulations more stringent than the requirements contained in this specification. When this document is specified for such tanks, it should be followed insofar as it does not conflict with regulatory requirements.

      
      

   3. Once the tank has been placed into service, it should be maintained according to API 12R1, API 653, or an owner program specifically designed for tank maintenance.

2 Normative References

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda) applies.

AISC1 American Institute of Steel Construction Manual, 15th Edition API Specification 5L, Specification for Line Pipe

API 12R1, Recommended Practice for Setting, Maintenance, Inspection, Operation, and Repair of Tanks in Production Service