OFFSHORE STANDARDS DNVGL-OS-E402 Edition January 2017 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 offshore standards contain technical requirements, principles and acceptance criteria related to classification of offshore units. © DNV GL AS January 2017 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. DNV GL does not accept any liability or responsibility for loss or damages resulting from any use of this document. CHANGES – CURRENT This document supersedes DNV-OS-E402 Offshore standard for Diving systems, October 2010 and DNV-DS- E403 Standard for Surface Diving Systems, July 2012 Changes in this document are highlighted in red colour. However, if the changes involve a whole chapter, section or sub-section, normally only the title will be in red colour. January 2017, entering into force 1 July 2017 • General The following main changes were implemented in this document: — Combination of the content of the superseded documents referred above. Changes - current — Updating of (design) references to DNV GL service documents incl. DNV GL rules for classification: Ships. — Focusing of the scope of the document on diving systems by removal of content related to diving support vessels/unit arrangements and outer areas. — Removing procedural descriptions and requirements related to classification. In addition to the above, the following detail changes were made: • Ch.2 Sec.2 Life support systems including piping, hoses, valves, fittings, compressors, filters and umbilicals — Ch.2 Sec.2 [5.1.4]: Restrict the use of threaded pipe penetrations to max. thread size M30. — Ch.2 Sec.2 [8]: Restrict the use of detachable connections to max 25 mm (1”). • Ch.3 Sec.1 Design philosophy and premises — Ch.3 Sec.1 [9.1.2]: Removed reference to specific parts of ISO 9001. • Ch.3 Sec.2 Pressure vessels for human occupancy, gas storage and other purposes — Ch.3 Sec.2 [1.6.2], Ch.3 Sec.2 [2.3.10] Guidance note, Ch.3 Sec.2 [4.1.3] and Ch.3 Sec.2 [4.1.3]Guidance note, design life with respect to fatigue to be defined by the designer. — Ch.3 Sec.2 [5.1.5]: Added guidance note. • Ch.3 Sec.3 Life support systems — Ch.3 Sec.3 [5.1.6]: Restrict the use of threaded pipe penetrations to max. thread size M30. • Ch.3 Sec.6 Launch and recovery systems — Ch.3 Sec.6 [3.2.1]: Text related to safety factors revised to be in line with Ch.2 Sec.6 [3.2.1]. • Ch.3 Sec.7 Pipes, hoses, valves, fittings, compressors, filters and umbilicals — Ch.3 Sec.7 [4.1.1]: Restrict the use of detachable connections to max 25 mm (1”). — Ch.3 Sec.7 [5.1.4]: Updated and more specific requirements to the compressor/filter pack. Editorial corrections In addition to the above stated changes, editorial corrections may have been made. Offshore standards, DNVGL-OS-E402. Edition January 2017 Page 3 Diving systems DNV GL AS CONTENTS Changes – current............................................................ 3 Chapter 1 Introduction..................................................... 8 Contents Section 1 General................................................................................................................ 8 1 Introduction......................................................................................................... 8 2 References........................................................................................................... 9 Chapter 2 Surface diving systems...................................25 Section 1 Design philosophy and premises........................................................................25 1 Introduction....................................................................................................... 25 2 Documentation philosophy.................................................................................25 3 Safety philosophy...............................................................................................27 4 Surface diving system philosophy......................................................................29 5 External and internal environmental conditions.................................................31 Section 2 Pressure vessels for human occupancy, gas storage and other purposes...........35 1 Introduction....................................................................................................... 35 2 General principles for design of chambers.........................................................39 3 Welded pressure vessels, materials, fabrication and strength........................... 42 4 Gas cylinders......................................................................................................44 5 Acrylic plastic windows......................................................................................45 Section 3 Life support systems including piping, hoses, valves, fittings, compressors, filters and umbilicals.................................................................................................... 47 1 Introduction....................................................................................................... 47 2 Gas storage........................................................................................................52 3 Gas distribution and control system.................................................................. 53 4 Diver’s heating and environmental conditioning in chambers............................ 55 5 Piping systems................................................................................................... 57 6 Hoses................................................................................................................. 57 7 Valves.................................................................................................................58 8 Fittings and pipe connections............................................................................ 59 9 Pressure regulators............................................................................................59 10 Compressors for breathing gas systems.......................................................... 59 11 Purification and filter systems......................................................................... 59 12 Umbilicals.........................................................................................................60 Section 4 Electrical systems.............................................................................................. 61 1 Introduction....................................................................................................... 61 Offshore standards, DNVGL-OS-E402. Edition January 2017 Page 4 Diving systems DNV GL AS 2 System design....................................................................................................63 3 Equipment in general.........................................................................................66 4 Miscellaneous equipment................................................................................... 67 5 Cables.................................................................................................................68 Section 5 Fire prevention, detection and extinction.......................................................... 69 1 Introduction....................................................................................................... 69 Contents 2 Fire protection................................................................................................... 70 3 Fire detection and alarm system....................................................................... 70 4 Fire extinguishing.............................................................................................. 71 5 Miscellaneous equipment................................................................................... 71 Section 6 Launch and recovery systems (LARS)................................................................72 1 Introduction....................................................................................................... 72 2 Design principles................................................................................................74 3 Strength............................................................................................................. 77 Section 7 Instrumentation and communication................................................................. 80 1 Introduction....................................................................................................... 80 2 Instrumentation................................................................................................. 81 3