RUSSIAN MARITIME REGISTER OF SHIPPING Corr. RULES FOR THE CLASSIFICATION AND CONSTRUCTION OF SUBSEA PIPELINES Saint-Petersburg 2017 The Rules for the Classification and Construction of Subsea Pipelines of Russian Maritime Register of Shipping have been approved in accordance with the established approval procedure and come into force on 1 July 2017. The Rules cover all technical aspects of design and construction of offshore subsea pipelines. In development of the Rules experience of other classification societies has been taken into consideration. ISBN 978-5-89331-260-7 © Российский морской регистр судоходства, 2017 CONTENTS PART I. SUBSEA PIPELINES 7 Corrosion protection 73 7.1 General 73 1 General 5 7.2 Protection against internal corrosion 73 1.1 Scope of application 5 7.3 Protection against external corrosion 74 1.2 Terms and definitions 5 7.4 Electrochemical protection 76 1.3 Classification 6 7.5 Electrical insulating joints 80 1.4 Scope of surveys 7 7.6 Corrosion monitoring systems 81 1.5 Technical documentation 9 8 Pipeline installation and testing 82 2 Design loads acting on subsea pipelines . 12 8.1 General 82 2.1 General 12 8.2 Pipeline routes and seabed soils 82 2.2 Design pressure 12 8.3 Additional measures for protection of the pipeline 2.3 Temperature effects 13 in the areas of intense ice gouging 85 2.4 Weight effects 13 8.4 Marine operations for pipeline laying .... 87 2.5 Current loads 13 8.5 Methods of pipeline laying on seabed .... 88 2.6 Wave loads and wind loads 14 8.6 Subsea pipeline testing by pressure 90 2.7 Variable hydrodynamic loads 14 9 Maintenance and repair 92 2.8 Seismic loads 15 9.1 Maintenance 92 3 Strength of subsea pipelines 16 9.2 Repair of subsea pipelines 93 3.1 General 16 10 Safety assessment 95 3.2 Determination of the steel pipeline wall thickness 16 10.1 Scope of application 95 3.3 Steel subsea pipeline calculations for buckling 10.2 Terms, definitions and explanations 95 (collapse) under hydrostatic pressure .... 17 10.3 Basic principles 96 3.4 Steel subsea pipeline local buckling analysis 18 10.4 Basic requirements for risk analysis 97 3.5 Steel subsea pipeline propagation buckling analysis 18 10.5 Methods of risk analysis 99 3.6 Steel subsea pipeline fatigue analysis. ... 18 3.7 Steel subsea pipeline seismic forces analysis 19 3.8 Strenght calculation for structural components PART II. RISERS of the pipeline consisting of flexible pipes . 20 4 Materials 23 1 General 100 4.1 General 23 1.1 Scope of application 100 4.2 Survey and technical supervision 23 1.2 Definitions and abbreviations 100 4.3 Procedures of testing pipes and steel rolled 1.3 Classification 101 products 29 1.4 Scope of surveys 101 4.4 Steel materials selection 34 1.5 Technical documentation 102 4.5 Steel for subsea pipelines 35 2 Design loads 103 4.6 Materials of flexible polymer-metal pipes 3 Requirements for determining riser dynamic and their end fittings 40 response to environmental conditions 4.7 Steel flanges 41 and loads 104 4.8 Steel bends and fittings 44 3.1 General 104 5 Welding 50 3.2 Determining riser elastic static line .... 104 5.1 General 50 3.3 Determining dynamic response 104 5.2 Weldability tests 51 3.4 Local strength criteria of riser pipes . ... 105 5.3 Production requirements for manufacturing 4 Materials 106 processes of subsea pipeline welded structures. 55 4.1 General 106 5.4 Inspection and defect acceptance limits 4.2 Metal riser pipes 106 for welded joints 60 4.3 Riser pipes of composite materials 106 5.5 Application of engineering critical assessment 4.4 Polymer-metal riser pipes 107 to determine the permissible defects 5 Corrosion protection 108 for girth welds 64 6 Riser construction, installation and testing 109 6 Ballasting of subsea pipelines 70 7 Riser maintenance and repair 110 6.1 General 70 7.1 General 110 6.2 Continuous weight coatings 70 4 Rules for the Classification and Construction of Subsea Pipelines 7.2 Technical supervision of risers in operation. 110 Appendix 6. Determination of factors 7.3 Riser repair Ill to calculate wave loads 140 Appendix 1. Recommendations on provision Appendix 7. Models of subsea pipeline dynamic of reliability and safety of subsea pipelines response to vortex-induced vibrations ... 143 on seabed soil 112 Appendix 8. Basic requirements for subsea Appendix 2. Indices of risk analysis 116 steel pipeline strength tested under seismic Appendix 3. Methods of risk analysis. 118 loads 145 Appendix 4. Special test procedures for steeled Appendix 9. Strength and stability of riser pipes and rolled products 125 pipes made of composite materials .... 149 Appendix 5. Determination of values of wave particle velocities and accelerations in bottom layer 133 PART I. SUBSEA PIPELINES 1 GENERAL 1.1 SCOPE OF APPLICATION ascertain that the materials, structures, arrangements and products in question meet the requirements ensuring the safety of media transportation through the subsea 1.1.1 Requirements of the present Part of the Rules pipelines. See Circular 1216 for the Classification and Construction of Subsea 1.1.8 In case referred to in 1.1.6, the Register may Pipelines (hereinafter referred to as "the SP Rules") require special tests to be carried out during construction, cover the pipelines designed, constructed and operated and may reduce the intervals between periodical surveys offshore, subsea crossings of sections of shore main or extend the scope of these surveys during operation. pipelines to the isolation valve nearest to the shoreline 1.1.9 The Register may approve subsea pipelines conveying liquid, gaseous and two-phase hydrocarbons constructed in compliance with other rules, regulations or as well as other media capable of being transported standards alternatively or additionally to the SP Rules. In through the pipelines. justified cases, the pipelines shall comply with the In addition to the SP Rules during performance of requirements of the SP Rules within the time period the technical supervision Russian Maritime Register of agreed upon with the Register. Shipping (hereinafter referred to as "the Register") also 1.1.10 Design, construction and operation of subsea applies the Guidelines on Technical Supervision During pipelines shall meet the requirements of national super• Construction and Operation of Subsea Pipelines (here• visory bodies. inafter referred to as "the SP Guidelines"), the Guidelines on Technical Supervision of Industrial Safety of Hazardous Production Facilities and their Equipment as 1.2 TERMS AND DEFINITIONS well as the standards and rules of the national technical See Circular 1216 supervisory bodies. 1.1.2 In each particular case the scope of technical Atmospheric zone means the part of the supervision carried out by the Register shall be stipulated pipeline above the splash zone. by a special agreement with the pipeline owner and/or Burial depth means the difference between operating organization and, if necessary, agreed upon the level of the pipeline top and the natural level of the with the national technical supervisory bodies. seabed soil. 1.1.3 The SP Rules do not cover ship's hoses. Splash zone height means the vertical The hoses shall comply with the requirements of Section 6, distance between splash zone upper limit and splash Part VIII "Systems and Piping" of the Rules for zone lower limit. the Classification and Construction of Sea-Going Ships. Flexible pipes for subsea pipelines Additional requirements may be imposed on the hoses mean polymeric-metal pipes with end connecting within the subsea pipelines depending on the application. fittings, which allow large deflections from straightness 1.1.4 The requirements specified by the SP Rules without a significant increase in bending stresses cover the documentation on subsea pipelines, the scope (generally, the design pressure for flexible pipes shall of surveys, strength, materials and welding, on-bottom comprise at least 1,6 MPa). stability, corrosion protection, laying methods, depth of Sea depth means the vertical distance measured burial into the seabed soil in the freezing water, testing, from the seabed to the average water level plus the total operation and safety assessment of subsea pipelines. height of astronomical and storm tides. 1.1.5 The SP Rules are applicable to single pipelines, Over-pressure means the difference between pipeline bundles and pipelines of "pipe-in-pipe" type. two absolute pressures, namely, outside hydrostatic and 1.1.6 The SP Rules may be applied to existing internal pressures. pipelines built without the RS technical supervision for Free span of pipeline means the length of the purpose of carrying out survey of technical condition the pipeline part not touching the seabed or supporting and evaluating the possibility of the RS class assignment. facilities. 1.1.7 The Register may allow to use materials, Permissible stresses mean the total structures, arrangements and products, other than those maximum stresses in the pipeline (longitudinal, hoop required by the SP Rules provided that they are as and tangential) permitted by standards. effective as those specified by the SP Rules. In the above Pipeline burial means placing of a subsea cases, data shall be submitted to the Register enabling to pipeline below the natural level of the seabed soil. 6 Rules for the Classification and Construction of Subsea Pipelines Splash zone means the pipeline section periodi• pipelines into the soil or for the preliminary trench cally flown over by the water due to wave and current excavation. effects and water level fluctuations. Pipe-layer (pipe-laying vessel/ Test pressure means the rated pressure applied barge) means the special purpose vessel intended for to the pipeline during testing before its commissioning. laying of subsea pipelines.