Choke and Kill Equipment

API SPECIFICATION 16C THIRD EDITION, MARCH 2021

API MONOGRAM PROGRAM EFFECTIVE DATE: SEPTEMBER 2021

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Foreword

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iii

Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 3

   1. Terms and Definitions 3

   2. Abbreviations 8

4. Application and Design Requirements 9

   1. Application 9

   2. Service Conditions 10

   3. Product Specification 13

   4. Design Method 14

   5. Performance Requirements 17

   6. Design Validation 18

   7. Closure Bolting 18

   8. Clamps 18

   9. Test, Vent, Pipe Plugs, and Gauge Connectors 18

   10. Design Documentation 18

5. Material Requirements 19

   1. General 19

   2. Metallic Parts 19

   3. Nonmetallic Parts 19

   4. Bolting for Choke and Kill Equipment. 20

   5. Flexible Lines 20

   6. Special Materials 20

   7. Casting Practices 20

   8. Hot Work Practices 21

   9. Chemical Composition 21

   10. Qualification Test Coupon 22

   11. Heat Treatment-Equipment and Quenching 22

   12. Mechanical Testing 22

   13. Mud Gas Separators (Atmospheric) 22

6. Welding 24

   1. General 24

   2. Welding Procedure and Performance Qualification 25

   3. Pressure-containing Fabrication Weldments 25

   4. Pressure-containing Repair Weldments 26

   5. Weld Overlay 27

   6. Weld NDE 28

   7. Repair Welds 30

7. Quality Control 31

   1. Measuring and Testing Equipment 31

   2. Quality Control Personnel Qualifications 32

   3. Quality Control Requirements 33

   4. Hydrostatic and Function Testing 45

   5. Quality Control Record Requirements 51

8. Marking 52

   v

   Contents

   Page

   1. General 52

   2. Low- and High-stress Area Marking 52

   3. Equipment-specific Marking 52

   4. Hardness Marking for Bodies, Bonnets, and Flanges 53

9. Storing and Shipping 53

   1. Storing of Equipment 53

   2. Equipment and Parts Rust Prevention 54

   3. Hydraulic Operating System 54

   4. Storing of Nonmetallic Materials 54

   5. Storing of Ring Gaskets 54

   6. Shipping of Equipment 54

10. Equipment-specific Requirements 54

    1. Choke and Kill System Requirements. 54

    2. End and Outlet Connectors 55

    3. Ring Gaskets 56

    4. Well Control Chokes 56

    5. Actuators for Well Control Chokes 58

    6. Rigid Choke and Kill Lines 59

    7. Flexible Choke and Kill Lines 60

    8. Hydraulic Control System-Well Control Chokes 63

    9. Articulated Choke and Kill Lines 64

    10. Choke and Kill Line Valves 66

    11. Choke and Kill Manifold Assemblies 68

    12. Buffer Chamber 70

    13. Operating and Maintenance Manual Requirements 71

    14. Mud Gas Separators (Atmospheric) 71

    15. Flexloops 73

Annex A (normative) Design Validation Procedures 75

Annex B (normative) Heat Treating Equipment Qualification 96

Annex C (informative) Pipe Thermal Expansion Calculations 98

Annex D (normative) Well Control Choke Control Console System 100

Annex E (informative) Example Choke and Kill System Configurations 103

Annex F (informative) Atmospheric Mud Gas Separators 107

Annex G (normative) Charpy V-notch Impact Test Location for Weld Qualification 110

Figures

1. Example: Pressure Line with Cushion Targets 15

2. Example: Pressurized Line with Cushion Target T’s 16

3. Total Fluid Cushion Bore Depth Example 16

4. Intersecting Header Example 17

5. Typical Flexible Line Construction 60

6. Typical Bonded and Non-bonded Flexible Line Assemblies 60

7. Typical Flexible Line End Termination and End Connectors 61

8. Example of an Articulated Choke or Kill Line. 65

   vi

   Contents

   Page

9. Example Illustrating Points of Rotation 65

B.1 Thermocouple Locations 97

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

   Surface BOP Installations 103

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

   Surface BOP Installations 104

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

   Surface BOP Installations 104

4. Example Kill Line Assembly for 5K and Greater Rated Working Pressure Service—

   Surface BOP Installations 104

5. Example Kill Line Assembly for 5K and Greater Rated Working Pressure Service—

   Surface BOP Installations 105

6. Example Standpipe Choke Installation 105

7. Example Choke and Kill Manifold for Subsea Systems 106

G.1 Location of Charpy V-Notch Impact T 111

Tables

1. Temperature Rating for Metallic and Nonmetallic Materials and Flexible Lines 10

2. Equipment Bore Sizes and Rated Working Pressures 11

3. Union, Swivel Union, and Articulated Line Sizes and Rated Working Pressures 12

4. Flexible Line Sizes and Rated Working Pressures 13

5. Bolting Requirements 20

6. Pressure-containing Parts Material Composition Limits 21

7. Alloying Element Maximum Tolerance Range Requirements 22

8. Pressure-containing Parts Material Designation 23

9. Pressure-containing Parts Material Property Requirements 23

10. Acceptance Criteria Charpy V-notch Impact Requirements 24

11. Weld Inclusion Length Acceptance Criteria—Radiographic and Ultrasonic Methods 30

12. Quality Control Requirements for Bodies, Bonnets, Flex Loops, Rigid Choke

    and Kill Lines, and End and Outlet Connectors 34

13. Minimum Hardness Values 35

14. Castings Acceptance Criteria 38

15. Quality Control Requirements for Stems 38

16. Quality Control Requirements for Nonmetallic Seals 39

17. Quality Control Requirements for Pressure-containing Parts of Flexible Choke and Kill Lines 41

18. Quality Control Requirements for Rigid Piping 42

19. Quality Control Requirements for Mud Gas Separators 44

20. Quality Control Requirements—Assembled Equipment 44

21. Metallic Marking Requirements 53

22. Quality Control Requirements for Male and Female Subs 56

23. Performance Requirements for Well Control Chokes and Actuators 58

24. Flexible Line Sizes and Pressure Requirements 61

25. Flexible Choke and Kill Line Flexible Specification Level (FSL) 63

26. Color Coding of Articulated Choke and Kill Line Components 66

27. Corrosion Resistance Level Requirements 67

1. Standard Test Fluid 80

2. PQL Life Cycle Testing Requirements 92

3. Subsea Valve and Actuator Hyperbaric Testing 92

Choke and Kill Equipment

1. Scope

   
   

   This specification identifies requirements for the performance, design, materials, testing, inspection, welding, marking, handling, storing, shipment, and purchasing of surface and subsea choke and kill equipment for use in the petroleum and natural gas industries.

   
   

   These requirements provide for safe and functionally interchangeable surface and subsea choke and kill system equipment. This specification does not apply to field use or field testing. This specification also does not apply to repair of choke and kill equipment, except for weld repair in conjunction with manufacturing.

   
   

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

API Specification 16F, Specification for Marine Drilling Riser Equipment API Specification 20E, Specification for Alloy and Carbon Steel Bolting API Specification 20F, Specification for Corrosion-resistant Bolting

API Standard 6X, Design Calculations for Pressure-containing Equipment

API Recommended Practice 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class 1, Division 1, and Division 2

API Recommended Practice 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class 1, Zone 0, Zone 2

ASME Boiler and Pressure Vessel Code (BPVC)1, Section V, Non-Destructive Examination ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Pressure Vessels—Division 1 ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Alternate Rules ASME Boiler and Pressure Vessel Code (BPVC) 2004, Section VIII, Division 2, Appendix 6

ASME Boiler and Pressure Vessel Code (BPVC), Section IX, Welding and Brazing Qualifications

1 ASME International, 2 Park Avenue, New York, New York 10016-5990, www.asme.org.