RULES FOR CLASSIFICATION Offshore units DNVGL-RU-OU-0375 Edition July 2019 Diving systems The content of this service document is the subject of intellectual property rights reserved by DNV GL AS ("DNV GL"). The user accepts that it is prohibited by anyone else but DNV GL and/or its licensees to offer and/or perform classification, certification and/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on the basis of and/or pursuant to this document whether free of charge or chargeable, without DNV GL's prior written consent. DNV GL is not responsible for the consequences arising from any use of this document by others. The electronic pdf version of this document, available free of charge from http://www.dnvgl.com, is the officially binding version. DNV GL AS FOREWORD DNV GL rules for classification contain procedural and technical requirements related to obtaining and retaining a class certificate. The rules represent all requirements adopted by the Society as basis for classification. © DNV GL AS July 2019 Any comments may be sent by e-mail to [email protected] This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document. The use of this document by others than DNV GL is at the user's sole risk. Unless otherwise stated in an applicable contract, or following from mandatory law, the liability of DNV GL AS, its parent companies and subsidiaries as well as their officers, directors and employees ("DNV GL") for proved loss or damage arising from or in connection with any act or omission of DNV GL, whether in contract or in tort (including negligence), shall be limited to direct losses and under any circumstance be limited to 300,000 USD. CHANGES – CURRENT This document supersedes the July 2017 edition of DNVGL-RU-OU-0375. Changes in this document are highlighted in red colour. However, if the changes involve a whole chapter, section or subsection, normally only the title will be in red colour. Changes July 2019, entering into force 1 January 2020 Topic Reference Description Substitute selected definitions Ch.1 Sec.1 Selected definitions and terms have been substituted by and terms to those defined by references to DNVGL-CG-0550. This also applies to Ch.1 Sec.2 DNVGL-CG-0550 and to Ch.2. Changes - current Updates to inspection and App.B Over pressure tests are now explicitly not accepted for the testing requirements service inspections of pressure vessels. Ch.3 Sec.2 Removal of static load testing of the LARS at renewal. It was not possible to fully ascertain the condition of the LARS after completion of the test. Further the test had the possibility to increase a non detected damage. Regular inspections (including NDT) of condition shall now be included within the PMS based upon OEM guidance. Removal of leak testing measured through pressure drop. This test provided a level of third party certification toward ensuring excessive helium use was avoided and was based upon contracting practices that are no longer common. Testing based on a safety level shall be implemented within the PMS system. A certificate based upon the existing testing may be requested where this may be useful, but is no longer a requirement. Removal of set schedules for pressure vessel testing which shall now be based upon the pressure vessel code (default table based upon ISO). Over pressure tests (hydro and pneumo) with the exception of volume expansion are no longer accepted as a method of confirming condition in service. The inspections for view ports have been revised to better support the ASME PVHO code and required roles/reporting. Buoyancy check for the bell may now be based upon the properties of the buoyancy materials, allowance for the use of a test block is also now supported. App.B Removal of pressure vessel testing every five years and reverting to the ISO requirement of every ten years. For gas bottles in service underwater this is changed from 2 years to 10 years. The earlier testing frequency was not addressing the expected degradation (corrosion) and visual inspection is adequate for that purpose. The earlier appendix B has been deleted as it was more of a guidance document than rules. It was also not commonly used. appendix C Pressure containing equipment is now appendix B. Rules for classification: Offshore units — DNVGL-RU-OU-0375. Edition July 2019 Page 3 Diving systems DNV GL AS Topic Reference Description Use of PMS or other auditable Ch.3 Sec.1 The use of a PMS system as a basis to ensure continued good items to focus testing, condition of a diving system is now mandatory. Requirements inspection and to facilitate are based upon existing practice for ships/offshore units. survey planning. Ch.3 Sec.2 The survey planning document is now explaining the scope of the system and is the basis for approving the content of the PMS system. It shall also demonstrate OEM requirements, procedures used during maintenance and testing as well as the link to the FMEA. Only annual scope listed. Inspection cycles for equipment will now vary based upon the equipment and design standard so while larger inspections are still required their timing shall be Changes - current agreed within the survey planning document. Ch.3 Sec.2 Scope for the PMS is based on requirements that were published in the now withdrawn DNVGL-RP-E403. Additional system specific requirements added referening OEM instructions and failure mode effect analysis (FMEA). Editorial corrections In addition to the above stated changes, editorial corrections may have been made. Rules for classification: Offshore units — DNVGL-RU-OU-0375. Edition July 2019 Page 4 Diving systems DNV GL AS CONTENTS Changes – current............................................................ 3 Chapter 1 Principles and procedures for classification...... 8 Contents Section 1 General................................................................................................................ 8 1 Introduction......................................................................................................... 8 1.1 Objective..........................................................................................................8 1.2 Scope.............................................................................................................. 8 1.3 Application....................................................................................................... 8 1.4 Organisation of this document............................................................................9 2 References........................................................................................................... 9 2.1 Normative references........................................................................................ 9 2.2 Informative references..................................................................................... 12 2.3 Terminology and definitions.............................................................................. 12 2.4 Abbreviations and symbols............................................................................... 19 Section 2 Principles and procedures for classification.......................................................23 1 Introduction....................................................................................................... 23 2 Classification principles......................................................................................23 2.1 The classification concept................................................................................. 23 2.2 Statutory certification...................................................................................... 23 3 Classification scope and notations..................................................................... 24 3.1 Scope............................................................................................................ 24 3.2 Class notations............................................................................................... 24 4 Assignment of class........................................................................................... 25 4.1 Assignment of class - new systems................................................................... 25 4.2 Survey during construction...............................................................................27 4.3 Assignment of class - existing systems.............................................................. 29 4.4 Classification certificate.................................................................................... 30 5 Retention of class.............................................................................................. 30 5.1 Conditions of retention of class.........................................................................30 5.2 Damage and repairs........................................................................................ 30 5.3 Withdrawal of class......................................................................................... 31 6 Certification of materials, components and systems.......................................... 31 6.1 Introduction.................................................................................................... 31 6.2 Type approval................................................................................................. 31 7 Legal provisions................................................................................................