Recommended Practice for Flexible Pipe Ancillary Equipment

API RECOMMENDED PRACTICE 17L2 FIRST EDITION, MARCH 2013

REAFFIRMED, AUGUST 2020

Special Notes

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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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Users of this Recommended Practice 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.

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Copyright © 2013 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, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. 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Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years.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 by API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.

Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.

This standard shall become effective on the date printed on the cover but may be used voluntarily from the date of distribution. Standards referenced herein may be replaced by other international or national standards that can be shown to meet or exceed the requirements of the referenced standard.

This standard is under the jurisdiction of the API Subcommittee on Subsea Production Systems. API Subcommittee 17 documents consists of the following:

• RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations

• RP 17B, Recommended Practice for Flexible Pipe

• RP 17C, Recommended Practice on TFL (Through Flowline) Systems

• Spec 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment

• Spec 17E, Specification for Subsea Umbilicals

• Spec 17F, Specification for Subsea Production Control Systems

• RP 17G, Recommended Practice for Completion/Workover Risers

• RP 17H, Remotely Operated Vehicle (ROV) Interfaces on Subsea Production Systems

• Spec 17J, Specification for Unbonded Flexible Pipe

• Spec 17K, Specification for Bonded Flexible Pipe

• Spec 17L1, Specification for Flexible Pipe Ancillary Equipment

• RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment

• RP 17M, Recommended Practice on Remotely Operated Tool (ROT) Intervention Systems

• RP 17N, Recommended Practice for Subsea Production System Reliability and Technical Risk Management

• RP 17O, Recommended Practice for Subsea High Integrity Pressure Protection Systems (HIPPS)

• RP 17P, Subsea Structures and Manifolds (in press)

• RP 17Q, Subsea Equipment Qualification–Standardized Process for Documentation

iii

Contents page

1. Scope. 1

2. Normative References 2

3. Terms, Definitions and Abbreviated terms. 3

   1. Terms and Definitions 3

   2. Symbols and Abbreviated Terms 14

4. General Recommendations 16

   1. Introduction 16

   2. Ancillary Equipment Description 18

   3. Design Considerations 39

   4. Materials 43

   5. Analysis Considerations 45

   6. Prototype Testing 47

   7. Manufacturing 50

   8. Handling, Transportation and Installation 52

   9. Integrity Management 53

5. Bend Stiffeners 56

   1. Applicability 56

   2. Design Considerations 56

   3. Materials 67

   4. Analysis Considerations 69

   5. Prototype Testing 72

   6. Manufacturing 74

   7. Handling, Transportation and Installation 76

   8. Integrity Management 77

6. Bend Restrictors 78

   1. Applicability 78

   2. Design Considerations 78

   3. Materials 84

   4. Analysis Considerations 86

   5. Prototype Testing 90

   6. Manufacturing 92

   7. Handling and Installation 93

   8. Integrity Management 94

7. Bellmouths 99

   1. General 99

   2. Design Considerations 99

   3. Materials 102

   4. Analysis Considerations 103

   5. Manufacturing Process—Metallic Bellmouths 105

   6. Prototype Tests 106

   7. Installation 108

   8. Integrity Management 108

8. Buoyancy and Ballast Modules 112

   1. Applicability 112

   2. Design Considerations 112

   3. Materials 121

   4. Analysis Considerations 124

   5. Prototype Tests 125

   6. Manufacturing 127

   7. Handling and Installation 129

   8. Integrity Management 131

9. Subsea Buoys 136

   1. Applicability 136

   2. Design Considerations 136

   3. Materials 143

   4. Analysis Considerations 144

   5. Prototype Testing 146

   6. Manufacturing 146

   7. Handling and Installation 147

   8. Integrity Management 150

   9. Decommissioning—Buoyancy Tank Subsea Buoys 151

10. Tethers 155

    1. Applicability 155

    2. Design Considerations 155

    3. Materials 157

    4. Analysis Considerations 158

    5. Prototype Testing 158

    6. Manufacturing 159

    7. Handling and Installation 159

    8. Integrity Management 160

11. Riser and Tether Bases 164

    1. Applicability 164

    2. Design Considerations 164

    3. Analysis Considerations 166

    4. Handling and Installation 168

    5. Integrity Management 169

12. General Clamping Device Recommendations 174

    1. General 174

    2. Design Considerations 174

    3. Materials 175

    4. Prototype Testing 176

    5. Installation 177

13. Subsea Buoy Clamps 177

    1. Applicability 177

    2. Design Considerations 177

    3. Materials 180

    4. Analysis Considerations 180

    5. Manufacturing 181

    6. Prototype Tests 181

    7. Installation 182

    8. Integrity Management 182

14. Tether Clamps 186

    1. Applicability 186

    2. Design Considerations 186

    3. Materials 190

    4. Analysis Considerations 191

    5. Prototype Tests 192

    6. Manufacturing 192

    7. Installation 193

    8. Integrity Management 194

15. Piggy-back Systems 198

    1. Applicability 198

    2. Design Considerations 198

    3. Materials 201

    4. Analysis Considerations 202

    5. Manufacturing 202

    6. Prototype Testing 203

    7. Installation 204

    8. Integrity Management 205

16. Repair Clamps 211

    1. Applicability 211

    2. Design Considerations 211

    3. Materials 213

    4. Analysis Considerations 213

    5. Installation 214

    6. Integrity Management 216

17. I/J-tube Seals 220

    1. Applicability 220

    2. Design Considerations 220

    3. Materials 226

    4. Manufacturing 226

    5. Prototype Testing 227

    6. I/J-tube Seal Installation 228

    7. Integrity Management 229

18. Pull-in Heads 232

    1. General 232

    2. Design Considerations 232

    3. Analysis Considerations 233

    4. Integrity Management 233

19. Chinese Fingers/Cable Grips 235

    1. Design Considerations 235

    2. Chinese Finger Materials 235

    3. Analysis Considerations 235

    4. Prototype Testing 235

    5. Handling and Installation 237

    6. Integrity Management 239

20. Connectors 239

    1. Applicability 239

    2. Design Considerations 240

    3. Analysis Considerations 240

    4. Manufacturing 241

    5. Prototype Testing 241

    6. Handling and Installation 242

    7. Integrity Management 242

21. Load-transferring Devices 245

    1. Applicability 245

    2. Design Considerations 245

    3. Analysis Considerations—Local Analysis 247

    4. Installation 247

    5. Integrity Management 249

22. Mechanical Protection 252

    1. Applicability 252

    2. Design Considerations 252

    3. Materials 254

    4. Analysis Considerations 255

    5. Prototype Testing 256

    6. Handling and Installation 259

    7. Integrity Management 260

23. Fire Protection 264

    1. Applicability 264

    2. Design Considerations 264

    3. Materials 266

    4. Analysis Considerations 267

    5. Prototype Testing 267

    6. Installation 270

    7. Integrity Management 270

Bibliography 272

Introduction

This Recommended Practice is the result of a Joint Industry Project to develop a worldwide industry standard for the design, material selection, analysis, testing, manufacture, handling, transportation, installation and integrity management of flexible pipe ancillary equipment. The objective of this Recommended Practice is to provide an integrated approach, together with API 17B, API 17J and API 17L1, to the design of flexible pipe systems. Therefore it is intended that this Recommended Practice be used in close conjunction with these documents.

The majority of ancillary equipment is custom-built and can be designed and manufactured in a variety of methods. It is not the intent of this Recommended Practice to discourage novel or new developments in ancillary equipment. On the contrary, it is recognized that a variety of designs and methods are possible. For this reason, some topics are presented in general terms to provide guidance to the user while still leaving open the possibility of using alternative approaches. The reader should be aware that ancillary equipment technology (concepts, design and analysis methodologies and criteria, components manufacturing and testing, operational roles and demands, maintenance and inspection, etc.) is in a state of rapid and continuing evolution. Potential users therefore need to apply care in their application of the recommendations herein.

Within this document, “shall” is used to state that a provision is mandatory; “should” is used to state that a provision is not mandatory, but is recommended as good practice; “may” is used to state that a provision is optional.

Systeme Internationale (SI) units are identified first when cited in the document. United States Customary (USC) units may be given in brackets after the SI units.

Recommended Practice for Flexible Pipe Ancillary Equipment

1 Scope

This Recommended Practice provides guidelines for the design, materials selection, analysis, testing, manufacture, handling, transportation, installation and integrity management of flexible pipe ancillary equipment. It supplements API 17L1, which specifies minimum requirements for the design, material selection, manufacture, documentation, testing, marking and packaging of flexible pipe ancillary equipment.

This Recommended Practice presents the current best practice for design and procurement of ancillary equipment, and gives guidance on the implementation of the specification for standard flexible pipe ancillary products. In addition, this Recommended Practice presents guidelines on the qualification of prototype products.

The applicability relating to a specific item of ancillary equipment within this Recommended Practice is stated at the beginning of the section dedicated to that item of ancillary equipment.

This Recommended Practice applies to the following flexible pipe ancillary equipment:

• bend stiffeners;

  
  

• bend restrictors;

  
  

• bellmouths;

  
  

• buoyancy modules and ballast modules;

  
  

• subsea buoys;

  
  

• tethers for subsea buoys and tether clamps;

  
  

• riser and tether bases;

  
  

• clamping devices;

  
  

• piggy-back clamps;

  
  

• repair clamps;

  
  

• I/J-tube seals;

  
  

• pull-in heads/installation aids;

  
  

• connectors;

  
  

• load-transfer devices;

  
  

• mechanical protection;

  
  

• fire protection.

This document may be used for bonded flexible pipe ancillary equipment, though any requirements specific to these applications are not addressed.