Choke and Kill Equipment

API SPECIFICATION 16C SECOND EDITION, MARCH 2015

API MONOGRAM PROGRAM EFFECTIVE DATE: SEPTEMBER 28, 2015 ERRATA, JULY 2015

ERRATA 2, NOVEMBER 2015

ERRATA 3, FEBRUARY 2016

Special Notes

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Copyright © 2015 American Petroleum Institute

Foreword

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

iii

Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 3

   1. Terms and Definitions 3

   2. Abbreviations 10

4. Design Requirements 10

   1. Service Conditions 10

   2. Product Specification 11

   3. Design Method 14

   4. Performance Requirements 15

   5. Design Validation 15

   6. Bore Size and Rated Working Pressure 16

   7. Closure Bolting 16

   8. Clamps 16

   9. Test, Vent, Pipe Plugs, and Gauge Connections 16

   10. Design Documentation 16

5. Material Requirements 17

   1. General 17

   2. Written Specifications 17

   3. Drilling Chokes 18

   4. Closure Bolting 18

   5. Flexible Lines 18

   6. Pressure-containing Parts, Bodies, Bonnets, Stems, and End Connections 18

   7. Rigid Piping 21

   8. Qualification Test Coupons 22

6. Welding 25

   1. General 25

   2. Non-pressure-containing Weldments 25

   3. Pressure-containing Fabrication Weldments 25

   4. Pressure-containing Repair Weldments 29

   5. Weld Overlay 30

7. Quality Control 32

   1. General 32

   2. Measuring and Testing Equipment 32

   3. Quality Control Personnel Qualifications 34

   4. Quality Control Requirements 34

   5. Assembled Equipment 53

   6. Quality Control Record Requirements 58

8. Marking 60

   1. General 60

   2. Low Stress Area Marking 60

   3. High Stress Area Marking 60

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   4. Equipment-specific Marking 60

   5. Hardness Marking for Bodies, Bonnets, and Flanges 60

9. Storing and Shipping 60

   1. Storing 60

   2. Shipping 61

10. Equipment-specific Requirements 62

    1. General 62

    2. End and Outlet Connections 62

    3. Ring Gaskets 63

    4. Studs and Nuts 63

    5. Drilling Chokes 63

    6. Actuators for Drilling Chokes 65

    7. Rigid Choke and Kill Lines 67

    8. Flexible Choke and Kill Lines 67

    9. Hydraulic Control System—Drilling Chokes 70

1. Buffer Chamber 74

2. Choke and Kill Manifold Assemblies 74

3. Operating and Maintenance Manual Requirements 75

Annex A (informative) Use of the API Monogram by Licensees 77

Annex B (normative) Design Validation Procedures 80

Annex C (informative) Weld Preparation Designs 96

Annex D (informative) Heat Treating Equipment Qualification 101

Annex E (informative) Pipe Thermal Expansion Calculations 103

Annex F (informative) Purchasing Guidelines 105

Annex G (normative) Drilling Choke Control Console System 106

Annex H (informative) Example Choke and Kill System Configurations 109

Bibliography 114

Figures

1. Simple Geometric Shapes 23

2. Complex Shaped Components 23

3. Keel Block Configuration 24

4. Welding Procedure Qualification Rockwell Hardness Test Locations 27

5. Welding Procedure Qualification Vickers Hardness Test Location 28

6. Hardness Test Locations 31

7. Typical Flexible Line Construction 67

8. Typical Bonded and Non-bonded Flexible Line Assemblies 68

9. Typical Flexible Line End Fitting 69

10. Example of an Articulated Choke or Kill Line 73

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    Page

11. Example Illustrating “Points of Rotation”. 73

1. Pipe Butt Joints 96

2. U-Groove 96

3. Heavy Wall V-groove 97

4. Attachment Welds 97

5. Hole Repair 98

6. Excavation for Repair–Removal of Sample Discontinuities in Weld Metal and Base Metal 99

7. Bushing/Seat Cavity 100

D.1 Thermocouple Locations 102

1. Example Choke Manifold Assembly for 2K and 3K Rated Working Pressure Service—\

   Surface BOP Installations 109

2. Example Choke Manifold Assembly for 5K Rated Working Pressure Service—

   Surface BOP Installations 110

3. Example Choke Manifold Assembly for 10K or Greater Rated Working Pressure Service—

   Surface BOP Installations 111

4. Example Kill Line Assembly for 2K and 3K Rated Working Pressure Service—

   Surface BOP Installations 111

5. Example Kill Line Assembly for 5K Rated Working Pressure Service—Surface BOP Installations . . . 112

6. Example Kill Line Assembly for 10K and Greater Rated Working Pressure Service—

   Surface BOP Installations 112

7. Example Choke and Kill Manifold for Subsea Systems 113

Tables

1. Temperature Rating for Metallic and Nonmetallic Materials and Flexible Lines 11

2. Equipment Bore Sizes and Rated Working Pressures 12

3. Union, Swivel Union, and Articulated Line Sizes and Rated Working Pressures 13

4. Flexible Line Sizes and Rated Working Pressures 14

5. Pressure-containing Parts Material Property Requirements 18

6. Pressure-containing Parts Material Designation 19

7. Pressure-containing Parts Material Steel Composition Maximum Limits 19

8. Alloying Element Maximum Tolerance Range Requirements 19

9. Acceptance Criteria Charpy V-notch Impact Requirements 20

10. Quality Control Requirements for Bodies, Bonnets, Choke and Kill Lines, and End and

    Outlet Connections 35

11. Minimum Hardness Values 36

12. Hot Worked Parts Acceptance Criteria 40

13. Castings Acceptance Criteria 40

14. Weld Inclusion Length Acceptance Criteria—Radiographic Method 42

15. Weld Inclusion Length Acceptance Criteria—Ultrasonic Method 42

16. Quality Control Requirements for Stems 44

17. Quality Control Requirements for Pressure-controlling Metallic Parts 45

18. Quality Control Requirements for Pressure-containing Parts of Actuators 45

19. Quality Control Requirements for Non-metallic Sealing Material 46

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20. Quality Control Requirements for Pressure-containing Parts of Flexible Lines 48

21. Quality Control Requirements for Rigid Piping 49

22. Acceptance Criteria for Elongated Indications 50

23. Quality Control Requirements for Male and Female Subs 53

24. Quality Control Requirements—Assembled Equipment 54

25. Minimum Hydrostatic Test Pressures 55

26. Metallic Marking Requirements 61

27. Performance Requirements for Drilling Chokes and Actuators 65

28. Flexible Line Sizes and Rated Working Pressures 69

29. Flexible Choke and Kill Line Flexible Specification Level (FSL) 70

30. Color Coding of Articulated Choke and Kill Line Components 73

B.1 Standard Test Fluid 85

viii

Choke and Kill Equipment

1. Scope

   This specification establishes the minimum requirements for the design and manufacture of the following types of new equipment:

   
   

   1. articulated choke and kill lines;

      
      

   2. choke and kill manifold buffer chamber;

      
      

   3. choke and kill manifold assembly;

      
      

   4. drilling choke actuators;

      
      

   5. drilling choke controls;

      
      

   6. drilling chokes;

      
      

   7. flexible choke and kill lines;

      
      

   8. union connections used in choke and kill assemblies;

      
      

   9. rigid choke and kill lines;

      
      

   10. swivel unions used in choke and kill equipment.

   
   

   These requirements were formulated to provide for safe and functionally interchangeable surface and subsea choke and kill system equipment utilized for drilling oil and gas wells.

   
   

   Technical content provides the minimum requirements for performance, design, materials, welding, testing, inspection, storing, and shipping.

   
   

   See 4.2 for requirements on additional components that may be included in choke and kill system equipment.

   
   

   If product is supplied bearing the API Monogram and manufactured at a facility licensed by API, the requirements of Annex A apply.

   
   

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

API Specification 5B, Specification for Threading, Gauging and Thread Inspection of Casing, Tubing, and Line Pipe Threads

API Specification 5CT, Specification for Casing and Tubing

API Specification 5L, Specification for Line Pipe

API Specification 6A, Specification for Wellhead and Christmas Tree Equipment

API Specification 16A, Specification for Drill Through Equipment

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