Standard for Surface Diving Systems

Transcription

1 STANDARD DNV-DS-E403 Standard for Surface Diving Systems JULY 2012 The electronic pdf version of this document found through is the officially binding version

2 FOREWORD DET NORSKE VERITAS (DNV) is an autonomous and independent foundation with the objectives of safeguarding life, property and the environment, at sea and onshore. DNV undertakes classification, certification, and other verification and consultancy services relating to quality of ships, offshore units and installations, and onshore industries worldwide, and carries out research in relation to these functions. DNV service documents consist of among others the following types of documents: Service Specifications. Procedural requirements. Standards. Technical requirements. Recommended Practices. Guidance. The Standards and Recommended Practices are offered within the following areas: A) Qualification, Quality and Safety Methodology B) Materials Technology C) Structures D) Systems E) Special Facilities F) Pipelines and Risers G) Asset Operation H) Marine Operations J) Cleaner Energy O) Subsea Systems Det Norske Veritas AS July 2012 Any comments may be sent by to This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document, and is believed to reflect the best of contemporary technology. The use of this document by others than DNV is at the user's sole risk. DNV does not accept any liability or responsibility for loss or damages resulting from any use of this document.

3 Changes Page 3 CHANGES General This is a new document, incorporating requirements previously found in DNV-OS-E402.

4 Contents Page 4 CONTENTS Sec. 1 General... 9 A. Introduction... 9 A 100 Objectives... 9 A 200 Scope... 9 A 300 Application... 9 A 400 Relation to other DNV rules and other codes and standards A 500 Procedural A 600 Documentation A 700 Survey and testing requirements during and after manufacture and assembly...10 A 800 Survey and testing requirements during and after installation A 900 Marking and signboards A 1000 Materials B. References B 100 Normative references B 200 Informative references B 300 Terminology and definitions B 400 Terminology and definitions (continued) B 500 Abbreviations and symbols (guidance) C. Procedural Requirements C 100 Certification and approval requirements Sec. 2 Design Philosophy and Premises SURFACE Diving Systems A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval & certification A 600 Documentation A 700 Survey and testing requirements during and after manufacturing and assembly A 800 Survey and testing requirements during and after installation A 900 Marking and signboards A 1000 Materials B. Documentation B 100 General B 200 Documentation of arrangement B 300 Documentation of installation B 400 Documentation for systems in operation B 500 Documentation for systems in demobilisation B 600 Filing of documentation C. Safety Philosophy C 100 General C 200 Safety objective C 300 Systematic review C 400 Quality management systems C 500 Inspection and test plans D. SURFACE Diving System Philosophy D 100 General D 200 System integrity D 300 Essential services D 400 Emergency services D 500 Non-important services D 600 Layout and arrangement of the SURFACE diving system D 700 Wet-bell if installed E. External and Internal Environmental Conditions E 100 General E 200 External operational conditions E 300 Internal operational conditions (Inner area) E 400 Submerged components F. Installation of diving system on support vessel or fixed structure F 100 Location... 28

5 Contents Page 5 F 200 Physical protection F 300 Ventilation and lighting F 400 Electrical power supplies to the installed diving system F 500 Structural fire protection Sec. 3 Pressure Vessels for Human Occupancy, Gas Storage and other Purposes A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Marking and signboards A 1000 Materials B. General Principles for Design of Chambers B 100 General B 200 Design loads B 300 Foundations for pressure vessels for human occupancy and for gas storage B 400 Doors, hatches, windows, branches etc C. Welded Pressure Vessels, Materials, Fabrication and Strength C 100 Materials C 200 Fabrication C 300 Fabrication tolerances C 400 Structural analysis to determine strength C 500 Strength of vessels subjected to external pressure C 600 Flanges for windows D. Gas Cylinders D 100 General D 200 Heat treatment D 300 Tolerances and surface conditions E. Acrylic Plastic Windows E 100 General E 200 Materials E 300 Manufacturers of cast material E 400 Certification of cast material E 500 Certification of windows E 600 Geometry and thickness E 700 Fabrication E 800 In service inspection Sec. 4 Life Support Systems including PIPING, Hoses, Valves, Fittings, Compressors and Umbilicals A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation requirements A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Materials, including components for gases containing elevated oxygen levels B. Gas Storage B 100 Capacity B 200 Shut-off, pressure relief and drainage C. Gas Distribution and Control System C 100 General C 200 Control stands C 300 Basket and wet-bell (if wet-bell is employed) C 400 Chambers C 500 Stand-by diver at surface C 600 Nitrogen/oxygen mixing systems for direct supply for breathing... 44

6 Contents Page 6 D. Diver s Heating and Environmental Conditioning in Chambers D 100 General D 200 Heating of divers in the water D 300 Heating and cooling of chambers D 400 Noise reduction D 500 Gas circulation systems for chambers D 600 Removal of carbon dioxide E. Piping Systems E 100 General F. Hoses F 100 General G. Valves G 100 Valve design G 200 Chamber valves H. Fittings and Pipe Connections H 100 Detachable connections I. Pressure Regulators I 100 General J. Compressors J 100 General K. Umbilicals K 100 General K 200 Hoses K 300 Electrical cables K 400 Sheathing K 500 Strength members Sec. 5 Electrical Systems A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Markings and signboards A 1100 Materials B. System Design B 100 Design principles B 200 System voltages B 300 Main electric power supply system B 400 System functionality and design B 500 Emergency power supply system B 600 Transitional source B 700 Battery systems B 800 Electric power distribution B 900 Lighting B 1000 Vessel arrangement C. Equipment in general C 100 General requirements C 200 Environmental requirements C 300 Termination and cable penetrations C 400 Earthing C 500 Insulation D. Miscellaneous Equipment D 100 General D 200 Lighting equipment inner area E. Cables E 100 Application... 53

7 Contents Page 7 Sec. 6 Fire Prevention, Detection and Extinction A. Introduction A 100 Objective A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation requirements A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Markings and signboards A 1100 Materials B. Fire Protection B 100 Arrangement C. Fire Detection and Alarm System C 100 Outer area C 200 Inner area C 300 Fault detection D. Fire Extinguishing D 100 Outer area D 200 Inner area E. Miscellaneous Equipment E 100 Breathing apparatus and fire-fighter's outfit E 200 Portable fire extinguishers Sec. 7 Launch and Recovery Systems (LARS) A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Marking and signposts A 1100 Materials B. Design Principles B 100 General B 200 Divers basket and wet-bell (when installed) B 300 Function B 400 Recovery B 500 Power B 600 Umbilical C. Strength C 100 Design loads C 200 Dimensions C 300 Foundations for launch and recovery systems and lifting appliances Sec. 8 Instrumentation and Communication A. Introduction A 100 Objective A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Markings and signboards A 1100 Materials... 65

8 Contents Page 8 B. Instrumentation B 100 General B 200 Power supply to control and monitoring systems B 300 Monitoring and inspection during operation B 400 Pressure control system B 500 Control stands B 600 Pressure indicators in wet-bell and chambers B 700 Oxygen and carbon dioxide analysing systems in wet-bell and chambers B 800 Other gases B 900 Automatic environmental control systems (if employed) C. Communication C 100 General C 200 Visual observation of divers C 300 Voice communication systems Sec. 9 Evacuation Systems A. Introduction A 100 Objectives A 200 Scope A 300 Application A 400 References A 500 Procedural requirements, approval and certification A 600 Documentation A 700 Survey and testing requirements during and after manufacture A 800 Survey and testing requirements during and after assembly A 900 Survey and testing requirements during and after installation A 1000 Marking and signboards A 1100 Materials App. A Selection of Safety Objective A. Introduction A 100 General principles (informative) B. Trigger Questions B 100 Overall safety objective B 200 Assessment of risk B 300 Technical innovation B 400 Contractors experience B 500 Quality management systems C. Systematic Review/Analysis C 100 What to do and how? (informative)... 71

9 Sec.1 Page 9 SECTION 1 GENERAL A. Introduction A 100 Objectives 101 The objectives of this standard are to give criteria and guidance on design, fabrication, installation, testing and commissioning of SURFACE diving systems employing air or NITROX breathing medium. Procedural requirements for operation, maintenance, and re-qualification of diving systems are normally specified in the Classification rules but the technical requirements in this DNV standard do generally apply. 102 Further objectives of this standard are to: a) provide an internationally acceptable standard of safety for SURFACE diving systems by defining minimum requirements for the design, materials, fabrication, installation, testing, commissioning, operation, repair, and re-qualification b) serve as a technical reference document for classification and verification services c) serve as a technical reference document in contractual matters between purchaser and contractor d) serve as a guideline for designers, purchaser, and contractors. 103 The objectives of this section are to outline the functionality of the standard and the related codes, standards and recommended practices. 104 General guidance is provided as to the use and interpretation of the standard and text from IMO Code of Safety for Diving Systems, 1995 Resolution A.831 (19) is included for reference. In the IMO text, this code is referred to as the Code. 105 The text from IMO Code of Safety for Diving Systems, 1995 Resolution A.831 (19) is included as normative reference. A 200 Scope 201 The scope is defined in each section for the various disciplines and may refer to standards that apply to the discipline in general, such as for electrical systems. In these cases this DNV Standard (DS) only contains requirements that are particular to SURFACE diving systems, whereas the generic requirements are given in the referred rules, standard or code. The combined requirements shall then constitute the scope. 202 Requirements for the support vessels are given in DNV Rules for Classification of Ships Pt.5 Ch.16, such as the requirements for floatation and positioning ability. 203 Where the Code requires that a particular fitting, material, appliance, apparatus, item or type of equipment should be fitted or carried in a system, or that any particular provision should be made, or any procedure or arrangement complied with, the Administration may allow alternative arrangements in that system, provided that the Administration is satisfied that such alternatives are at least as effective as the requirements of the Code. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.5 Equivalents) The design of arrangements, systems and individual components may alternatively or supplementary to the Standard be based on recognized standards, codes, national regulations and other methods of safety and strength evaluation than specified in the Standard. The basis shall be equivalent to the requirements given in this Standard. 204 This section bears impact on all other sections. A 300 Application 301 DSV-SURFACE is normally restricted to d max (= maximum depth) < 60 msw (= metres sea water) and T op (= operating time) < 8 hours. 302 This standard applies to SURFACE diving systems for any location. The SURFACE diving system may thus be located on and operated from a ship, barge, mobile offshore platform, fixed offshore installation or an onshore site, in the latter case for training, research purposes and such. However, the standard primarily applies to SURFACE diving systems used in the petroleum and natural gas industries. For application in other industries, special considerations may need to be agreed by the parties to the contract and or involved statutory regulators. 303 The SURFACE diving systems may be categorised as: a) SURFACE diving systems with deck decompression chambers and a ladder or basket for deployment of divers

10 Sec.1 Page 10 b) for wet-bell deployment of divers 304 This standard is not applicable to SCUBA diving, closed bell operations utilising submersible decompression chambers, Saturation diving systems, submersibles including atmospheric diving suits, submarines or submarine rescue systems. A 400 Relation to other DNV rules and other codes and standards 401 The requirements in this standard are based on requirements given in DNV Rules for Classification of Ships, and principles outlined in DNV Standards (see B). 402 Where reference is made to codes other than DNV documents, the valid revision shall be taken as the revision that was current at the date of issue of this standard. 403 In case of conflict between requirements of this standard and a reference document, the requirements of this standard shall prevail. 404 This standard is intended to comply, as far as reasonably possible, with the requirements given in IMO Code of Safety for Diving Systems, 1995 Resolution A.831 (19). 405 There are no known major deviations to the IMO Code of Safety for Diving Systems, 1995 Resolution A.831 (19) except those marked as non-applicable text. Guidance note: Additional requirements for the SURFACE diving system may be applicable due to the statutory requirements given in certain geographic areas, or onboard ships flying certain flags. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e--- A 500 Procedural 501 Procedural requirements are given under A500 in each relevant section. A 600 Documentation 601 Documentation requirements are given under A600 in each relevant section. A 700 Survey and testing requirements during and after manufacture and assembly 701 Survey and testing requirements during and after manufacture and assembly are given under A700 in each relevant section and in DNV-RP-E401 Survey of Diving Systems. A 800 Survey and testing requirements during and after installation 801 Survey and testing requirements during and after installation are given under A800 in each relevant section and in DNV-RP-E401 Survey of Diving Systems. A 900 Marking and signboards 901 Marking and signboard requirements are given under A900 in each relevant section. A 1000 Materials 1001 Material specifications and requirements are given under A1000 in each relevant section. B. References B 100 Normative references 101 The latest revisions of the following Rules apply: Table B1 DNV Rules Title DNV Rules for Classification of Ships 102 The latest revisions of the following DNV Service specifications apply: Table B2 DNV Service Specifications Reference Title DNV-DSS-105 Rules for Certification and Verification of Diving Systems

11 Sec.1 Page The latest revisions of the following DNV Standards apply: Table B3 DNV Standards Reference Title DNV-OS-A101 Safety Principles and Arrangements 104 The latest revisions of the following DNV Recommended practices apply: Table B4 DNV Recommended Practices Reference Title DNV-RP-A201 Plan Approval Documentation Types Definitions 105 The latest revisions of the following DNV Standards for Certification and Classification notes apply: Table B5 DNV Standards for Certification and Classification notes Title Standard for Certification No Lifting Appliances 106 The latest revisions of the following DNV Guidelines apply: (Empty) 107 The latest revisions of the following other references apply: Table B6 Other normative references Reference Title ASME VIII Div.1 or Div. 2 1 ASME Boiler and Pressure Vessel Code ASME PVHO-1 Safety Standard for Pressure Vessels for Human Occupancy ASME PVHO-2 Safety Standard for Pressure Vessels for Human Occupancy in Service Guidelines for PVHO Acrylic Windows. ASTM G93 API BS 5355 EN 738-1, -2 and -3 Standard Practice for Cleaning Methods and Cleanliness Levels for Materials and Equipment Used in Oxygen-Enriched Environments Codes for hoses Specification for filling ratios and developed pressures for liquefiable and permanent gases. Pressure regulators for use with medical gases EN Transportable gas cylinders (part 1:1999, part 2:2001 or part 3:2000) EN 1968 Periodic Inspection and testing of Seamless gas cylinders EN ISO Gas cylinders - Refillable seamless steel tubes for compressed gas transport, of water capacity between 150 l and 3000 l - Design construction and testing (ISO 11120:1999): EN Unfired pressure vessels EN Welding - Basic weld joint details in steel IMO Code of Safety for Diving Systems, 1995 Resolution A.831(19), IMO MSC/Circ.645 of 6 June 1994 Guidelines for Vessels with dynamic positioning systems IMO Resolution A.809(19) In reference to SOLAS Regulation III/6.2.1 and III/ IMO res. MSC.61(67) (FTP Code) IMO resolution A.468 (XII) Code on noise levels onboard ships. IEC No International Electrotechnical Commission's Publication No.79-10, and IMO (MODU) Code chapter 6, ISO 6385 ISO 9000 ISO ISO , BS6501 ISO ISO (NFPA) Codes Ergonomic Principles in the Design of Work Systems Guidance on the selection and use of quality systems, and Guidance on developing quality manuals. Flexible metallic hoses Steel and Steel Products - Inspection Documents /EN Metallic Products - Types of Inspection Documents Petroleum and natural gas industries Design and operation of subsea production systems Part 5: Subsea control umbilicals National Fire Protection Agency

12 Sec.1 Page 12 Table B6 Other normative references (Continued) Reference Title PD Specification for Unfired Fusion Welded Pressure Vessels SAE J 517, DIN EN 853, 856, 857 Rubber Hoses and Hose Assemblies SOLAS 1974 with latest amendments 2 (International Convention for the Safety of Life at Sea). 1) Alternative codes and standards that shall be specified at the start of the project. 2) Relevant reference given in the text. Guidance note: The latest revision of the DNV documents may be found in the publication list at the DNV website For other sources see DNV-DSS-105 Appendix C. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e--- B 200 Informative references Table B7 Informative references Reference Title DNV-OS-D201 Electrical Systems and Equipment DNV-OS-D202 Instrumentation and Telecommunication systems DNV-OS-D301 Fire Protection DNV-RP-A201 Plan Approval Documentation Types - Definitions NORSOK Standard U-100 Manned Underwater Operations EN Transportable Gas Cylinders - Cylinder Valves - Specification and Type Testing EN ISO Transportable Gas Cylinders - Compatibility of Cylinder and Valve Materials with Gas Contents - Part 3: Autogenous Ignition Test in Oxygen Atmosphere EN ISO Gas Welding Equipment - Pressure Regulators for Gas Cylinders used in Welding, Cutting and Allied Processes up to 300 bar ILO Convention 133 Accommodation of crews 1) Alternative codes and standards that shall be specified at the start of the project. 2) Relevant reference given in the text. B 300 Terminology and definitions 301 The Society signifies Det Norske Veritas AS. 302 The EC signifies the Executive Committee of the Society. 303 Auxiliary Verbal forms are given as follows: 304 Shall/shall not : is used to indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. In the cases where text from the IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey is used, the IMO use of should shall be interpreted as shall. 305 Should : shall be used to indicate that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required, or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. 306 May/need not : shall be used to indicate a course of action permissible within the limits of the document. 307 Agreement, by agreement : Unless otherwise indicated, this means agreed in writing between the society, manufacturers, builder and owner. 308 Administration means the Government of the State whose flag a ship or floating structure which carries a diving system is entitled to fly or in which the ship or floating structure is registered. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.1) 309 As-built survey: Survey of the installed and completed diving system, which is performed to verify that the completed installation work meets the specified requirements, and to document deviations from the original design, if any. 310 Basket: A divers basket (sometimes known as a stage) is a frame and mesh construction designed to accommodate divers whilst they are lifted in and out of the water. 311 Bell: A diving bell is a frame incorporating a dome, and including appendages, for transfer of divers between the underwater work site and the deck or the surface chamber (TUP or DDC). In the context of this standard, bell is defined as an open bell/wet-bell. (See Open Bell, Closed Bell and Wet bell)

13 Sec.1 Page Bottle means a pressure container for the storage and transport of gases under pressure. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.2) 313 Breathing gas/breathing mixture means all gases/mixtures of gases which are used for breathing during diving operations. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.3) 314 Builder: In the context of these rules, signifies the party contracted to build a diving system in compliance with the Society's rules. 315 Built In Breathing System (BIBS): A system of gas delivery to masks, located in the decompression chambers, baskets and wet-bells. This system facilitates breathing in the event of a contaminated atmosphere, and allows for the use of therapeutic gases during decompression. (See Sec.4). BIBS may in rare cases be closed circuit breathing systems (see CCBS definition) but are normally open circuit systems where the exhaled gas is dumped to atmosphere. 316 Case by case: When the case by case approval procedure is used, documentation of the design shall be submitted for approval for each application as required in the applicable chapters of the rules. When the case by case survey procedure is used, the survey shall be performed on the basis of approved design documentation for the actual application and as required in the applicable sections of the rules. Compliance with the approved design documentation and applicable requirements will be documented by certificates as required in the applicable sections of the rules. 317 Category A machinery spaces are those spaces and trunks to such spaces as defined in the International Convention for the Safety of Life at Sea, 1974, as amended. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 318 Certificate: A document confirming compliance with the Society's rules or with other rules and regulations for which the Society has been authorized to act. 319 Certification: A service confirming compliance with applicable requirements on the date that the survey was completed. Materials and components in DNV Classified SURFACE diving systems shall be certified according to the level of certification given in DNV-DSS Chamber: Surface decompression, pressure or compression chambers (see also DDC), hereafter called the chambers, and are pressure vessels for human occupancy. 321 Class: In the context of these rules, Class is assigned to and will be retained by the diving system complying with applicable requirements of the Society's rules. 322 Classification: In the context of these rules, a service which comprises the development of independent technical standards for diving systems - and verifies compliance with the rules throughout the vessels' life. 323 Closed bell: A sealed submersible diving chamber (SDC) that locks on and off the chamber where the divers decompress (DDC). Pressure differentials are retained by way of a closed door sealing the divers in at pressures, elevated or lowered compared to the surrounding pressure. Closed bells are not covered by this standard. See DNV-DS-E402. (Note: currently under development, meanwhile use DNV-OS-E402). 324 Closed Circuit Breathing System (CCBS) : A system for supply of breathing gas to the diver and saving of his exhaled gases for re-circulation after scrubbing and replenishing. (see Sec.4) 325 Commissioning: In relation to diving systems, refers to activities which take place after installation and prior to operation, comprising the tests and trials outlined in Sec.2 J. 326 Compact umbilical: Umbilical consisting of composite bundles of hoses, cables and strength members in a braiding or sheathing. (See Sec.4) 327 Compartment: Part(s) of a chamber sufficiently large to contain at least one person and which may have an internal pressure different from adjacent compartments. (see Sec.3) 328 Construction phase: All phases during construction, including fabrication, installation, testing and commissioning, up until the installation or system is safe and operable for intended use. In relation to diving systems, this includes manufacture, assembly, testing, commissioning and repair. 329 Contractor: A party contractually appointed by the Purchaser to fulfil all, or any of, the activities associated with design, construction and operation. 330 Control stations normally as defined in regulation 3 and referred to in regulation 20, chapter II-2 of the International Convention for the Safety of Life at Sea. Control stand or Control station is a control station in which one or more of the following control and indicator functions are centralized: a) Indication and operation of all vital life support conditions, including pressure control b) Visual observation, communication systems including telephones, audio-recording and microphones to public address systems c) Disconnection of all electrical installations and Insulation monitoring d) Provisions for calibration of and comparison between gas analysing

14 Sec.1 Page 14 e) Indication of temperature and humidity in the inner area f) Alarms for abnormal conditions of environmental control systems g) Fixed fire detection and fire alarm systems h) Ventilation fans i) Automatic sprinkler, fire detection and fire alarm systems j) Launch and recovery systems, including interlock safety functions k) Operation and control of the hyperbaric evacuation system 331 Corrosion allowance: Extra wall thickness added during design to compensate for any reduction in wall thickness by corrosion (internally and externally) during operation. 332 Customer: Signifies the party who has requested the Society's service. 333 Deck Decompression Chamber (DDC): Deck mounted Pressure Vessel for Human Occupancy (PVHO) used for decompression. (See Sec.3) 334 Depth means the water depth or equivalent pressure to which the diver is exposed at any time during a dive or inside a surface compression chamber or a diving bell. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.6) 335 Design: All related engineering to design the diving system, including both structural as well as material and corrosion. 336 Design life: The initially planned time period from initial installation or use until permanent decommissioning of the equipment or system. The original design life may be extended after a re-qualification. 337 Design load: For PVHOs see Sec.3 B300/400 and for LARS see Sec.7 C Design temperature, maximum: The highest possible temperature to which the equipment or system may be exposed to during installation and operation. Environmental as well as operational temperatures shall be considered. Design temperature, minimum: The lowest possible temperature to which the equipment or system may be exposed to during installation and operation, irrespective of the pressure. Environmental as well as operational temperatures shall be considered. Guidance note: For LARS, the design temperature is defined in Standard for Certification Lifting Appliances. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e Designer: Signifies a party who creates documentation submitted to the Society for approval or information. 340 Diver heating: A system for actively heating the divers in the water or in the inner area. 341 Divers: Personnel subjected to higher ambient pressure than one atmosphere. 342 Diving bell means a submersible compression chamber, including its fitted equipment, for transfer of diving personnel under pressure between the work location and the surface compression chamber. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.7) 343 Diving system means the whole plant and equipment necessary for the conduct of diving operations. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.8) Diving system (in DNV terms): The whole plant and equipment necessary for safe conduct of diving operations where compression and decompression of divers are taking place. For classification purposes, SURFACE diving operations are categorized as d max < 60 msw and T op < 8 hours where msw is metres of sea water 344 dmax: Maximum operating depth of the SURFACE diving system. This is the depth corresponding to the maximum pressure for pressurizing divers. (For Classified systems this may be specified in the certificate and Data Sheet). 345 DSV: Class Notation in DNV representing Diving Support Vessel'. 346 ECU: Environmental Control Unit. Maintains Temperature, reduces humidity and may include removal of carbon dioxide. (see Sec.4) 347 Enriched air: Nitrogen oxygen mixtures with elevated oxygen content. (See NITROX) 348 Equipment lock: A pressure tight independent lock mounted on the shell of the chamber providing the means for locking in equipment necessary for the divers and the operation of the system. (See also Medical lock) 349 Evacuation system means a system whereby divers under pressure can be safely evacuated from a ship or floating structure to a position where decompression can be carried out. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.9) 350 Fabrication: Activities related to the assembly of objects with a defined purpose. In relation to diving systems, fabrication refers to e.g. deck decompression chambers, wet-bells, and pressure vessels for gas storage, environmental control systems, launch and recovery systems etc.

15 Sec.1 Page Fabricator: The party performing the fabrication (in this context, normally of windows for PVHOs). 352 Failure: An event affecting a component or system and causing one or both of the following effects: loss of component or system function deterioration of functional capability to such an extent that the safety of the installation, personnel or environment is significantly reduced 353 Fatigue: Cyclic loading causing degradation of the material. 354 Flag administration: The maritime administration of a vessel's country of registry. 355 Gas: In the context of this standard, gas includes air, oxygen and Enriched air/nitrox. 356 Gas containers: Cylinders, bottles and pressure vessels for storage of pressurized gas. (see Sec.3 and 4) 357 Guidance notes: Contain advice which is not mandatory for the assignment or retention of class, but with which the Society, in light of general experience, advises compliance. 358 Handling system means the plant and equipment necessary for raising, lowering and transporting the diving bell between the work location and the surface compression chamber. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) (See Launch and recovery System-LARS) 359 Hazardous areas are those locations in which an explosive gas-air mixture is continuously present, or present for long periods (zone O); in which an explosive gas-air mixture is likely to occur in normal operation (zone 1); in which an explosive gas-air mixture it not likely to occur, and if it does it will only exist for a short time (zone 2). (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 360 HAZOP (HAZard and OPerability study): The application of a formal systematic critical examination to the process and engineering intentions of new or existing facilities to assess the hazard potential of inadvertent operation or malfunction of individual items of equipment and their consequential effects on the facility as a whole (Chemical Industries Association HAZOP Guide). 361 Hydro-test or Hydrostatic test: See Pressure test 362 Hyperbaric Evacuation System (HES): System for evacuating divers under pressure. This includes the Hyperbaric Evacuation Unit (HEU), the launch and recovery and control systems. (See Sec.9) 363 Hyperbaric Rescue Vessel (HRV): IMO uses the term Hyperbaric Evacuation Unit (HEU). See above. 364 IACS: The International Association of Classification Societies. 365 IMO: Signifies the International Maritime Organization. 366 Inner area: The areas which are inside the chambers. Interconnecting trunks are considered part of the inner area when the door is opened into the chamber. 367 Inspection: Activities such as measuring, examination, testing, gauging one or more characteristics of a product or service and comparing the results with specified requirements for determine conformity. 368 Installation (activity): The operations related to installing the equipment, diving system or support structure, e.g. mounting chambers, gas cylinders, ECUs, panels, interconnecting piping, launch and recovery systems etc., including final testing and preparation for operation. 369 Installation Manual (IM): A document prepared by the Contractor to describe and demonstrate that the installation method and equipment used by the Contractor will meet the specified requirements and that the results can be verified. 370 ISO: Signifies the International Organisation for Standardization. 371 Launch and recovery system (LARS): The system and equipment necessary to launch and recover the divers, the diver s basket or wet-bell to the chambers as well as transport the divers between the surface support unit and the underwater working site, including any guide rope systems and cursor systems. (See Sec.7) 372 Lay-up: A terminology used for diving systems that are out of commission. In this state the diving system may be installed on board or permanently stored on shore. 373 Life support system means the gas supply, breathing gas system, decompression equipment, environmental control system and equipment required to provide a safe environment for the diving crew in the diving bell and the surface compression chamber under all ranges of pressure and conditions they may be exposed to during diving operations. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) Life support systems (in DNV terms): The systems comprising gas supply systems, breathing gas systems, pressure regulating systems, environmental control systems, and systems required to provide a safe habitat for the divers, in the basket, the wet-bell and the chamber compartments under normal conditions during SURFACE diving operation. (See Sec.4) 374 Living compartment means the part of the surface compression chamber which is intended to be used

16 Sec.1 Page 16 as the main habitation for the divers during diving operations and which is equipped for such purpose. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) Living compartment (in DNV terms): A compartment which is intended to be used as the main habitation for the divers and which is equipped as such. 375 Load: Any action causing stress, strain, deformation, displacement, motion, etc. to the equipment or system. 376 Load effect: Effect of a single load or combination of loads on the equipment or system, such as stress, strain, deformation, displacement, motion, etc. 377 Load effect factor: The partial safety factor by which the characteristic load effect is multiplied to obtain the design load effect. 378 Lot: A number of components from the same batch. E.g. same heat, the same heat treatment batch and with the same dimensions. 379 Main components of a diving system include the surface compression chamber, diving bell, handling system and fixed gas storage facilities. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 380 Manufacture: Making of articles or materials, often in large volumes. In relation to diving systems, refers to activities for the production of pressure vessels, panel, and life support systems etc., performed under contracts from one or more Contractors. 381 Manufacturer: Signifies the entity that manufactures the material or product, or carries out part production that determines the quality of the material or product, or does the final assembly of the product. 382 Mating device means the equipment necessary for the connection and a disconnection of a diving bell to a surface compression chamber. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 383 Maximum operating depth of the diving system is the depth in metres or feet of seawater equivalent to the maximum pressure for which the diving system is designed to operate. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 384 Medical lock: A pressure tight independent lock mounted on the shell of the chamber providing the means for locking in provisions, medicine and equipment necessary for the divers and the operation of the system. (See also Equipment lock) 385 NDE level: The extent and acceptance criteria for the NDE of the components. 386 NITROX: Nitrogen oxygen mixtures with elevated oxygen content. (See Enriched air) 387 Nominal outside diameter: The specified outside diameter. This shall mean the actual outside diameter. 388 Nominal wall thickness: The specified non-corroded wall thickness, which is equal to the minimum steel wall thickness plus the manufacturing tolerance. 389 Normal cubic meters: (Nm 3 ) is taken as cubic meters of gas at standard conditions of 0 C and bar. 390 Open bell (also known as Wet bell): A suspended canopy chamber, open at the bottom like a moon pool structure that is lowered underwater to operate as a stage for the divers with the advantage of providing an air pocket for refuge and a space for communication outside the mask/helmet. 391 Operation, Incidental: Conditions that are not part of normal operation of the equipment or system. In relation to diving systems, incidental conditions may lead to incidental pressures. 392 Operation, Normal: Conditions that arise from the intended use and application of equipment or system, including associated condition and integrity monitoring, maintenance, repairs etc. In relation to diving systems, this should include, start and finish of dives (pre- and post-dive checks), treatment of decompression-related incidents, gas transfer and changing out of consumables. 393 Organization means the International Maritime Organization (IMO). (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 394 Out of roundness: The deviation of the perimeter from a circle. This can be stated as ovalisation (%), or as local out of roundness, e.g. flattening, (mm). 395 Outer area: Those areas of the diving system that are exposed to atmospheric conditions during operation, i.e. outside the inner system and the room or area that surrounds or contains the diving system. 396 Ovalisation: The deviation of the perimeter from a circle. This has the form of an elliptic cross section. 397 Owner: Signifies the registered owner or manager of the diving system or any other organization or person who has assumed the responsibility for operation of the diving system and who on assuming such responsibility has agreed to take over all the duties and responsibilities. 398 Oxygen systems: Systems intended for a gas with a higher oxygen percentage than 25%. 399 Personal diving equipment: Equipment carried by the diver on his person including his tools, diving suit, diving helmet and self-contained breathing apparatus with gas bottles. This is normally not included in the SURFACE diving system specified in this standard.

17 Sec.1 Page 17 B 400 Terminology and definitions (continued) 401 Plan approval: Signifies a systematic and independent examination of drawings, design documents or records in order to verify compliance with the rules or statutory requirements. Plan approval will be carried out at the discretion of the Society, which also decides the extent and method of examination. 402 Planned Maintenance System (PMS): A system for planning and recording of maintenance activities. 403 Pressure control system: In relation to diving systems, this is the system for control of the pressure in the various systems, comprising the pressure regulating system, pressure safety system and associated instrument and alarm systems. 404 Pressure regulating system: In relation to diving systems, this is the system which ensures that, irrespective of the upstream pressure, a set pressure is maintained downstream (at a given reference point) for the component. 405 Pressure safety system: The system which, independent of the pressure regulating system, ensures that the allowable set pressure is not exceeded. 406 Pressure test: The hydrostatic pressure test initially performed at the manufacturer of the pressure vessel in accordance with requirements in the design code. 407 Pressure, Collapse: Characteristic resistance against external over-pressure. 408 Pressure, Design: In relation to diving system assemblies, this is the maximum internal pressure during normal operation, referred to a specified reference point, to which the component or system section shall be designed. The design pressure must take account of the various pressurised components in the adjoining systems, and their relative design pressures. 409 Pressure, System test: In relation to diving systems, this is the internal pressure applied to the component or system during testing on completion of installation work to test the diving system for tightness (normally performed as hydrostatic testing). 410 Pressure vessel means a container capable of withstanding an internal maximum working pressure greater than or equal to 1 bar. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) 411 Purchaser: The owner or another party acting on his behalf, who is responsible for procuring materials, components or services intended for the design, construction, installation or modification of a SURFACE diving system. 412 Quality Assurance (QA): Planned and systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements for quality. 413 Quality Plan (QP): The document setting out the specific quality practices, resources and sequence of activities relevant to a particular product, project or contract. A quality plan usually makes reference to the part of the quality manual applicable to the specific case. 414 Quality system: Signifies both the quality management system and established production and control procedures. 415 Reliability: The probability that a component or system will perform its required function without failure, under stated conditions of operation and maintenance and during a specified time interval. 416 Re-qualification: The re-assessment of a design due to modified design premises and or sustained damage. 417 Resistance: The capability of a structure, or part of a structure, to resist load effects. 418 Risk: The qualitative or quantitative likelihood of an accidental or unplanned event occurring, considered in conjunction with the potential consequences of such a failure. In quantitative terms, risk is the quantified probability of a defined failure mode times its quantified consequence. 419 Rules: All requirements adopted by the EC as the basis for classification. 420 Saturation diving: Once a diver becomes saturated with the gases that make decompression necessary, the diver does not need additional decompression. When the blood and tissues have absorbed all the gas they can hold at that depth, the time required for decompression becomes constant. As long as the depth is not increased, additional time on the bottom is free of any additional decompression. Saturation diving equipment is not covered in this standard. Reference is given to DNV-DS-E402. (Note: currently under development, meanwhile use DNV-OS-E402). 421 Self Propelled Hyperbaric Lifeboat (SPHL): (see HEU and DNV-DS-E402 (Note: currently under development, meanwhile use DNV-OS-E402).) 422 Significant wave height: When selecting the third of the number of waves with the highest wave height, the significant wave height is calculated as the mean of the selection. 423 Specified Minimum Tensile Strength: The minimum tensile strength prescribed by the specification or standard under which the material is purchased. 424 Specified Minimum Yield Stress: The minimum yield stress prescribed by the specification or standard under which the material is purchased.

18 Sec.1 Page Submersible Decompression Chamber (SDC): Closed bell. (Not applicable to this standard. See DNV- DS-E402. Note: under development, meanwhile use DNV-OS-E402). 426 Suitable breathing gas: A gas or gas mixture that is breathable to divers for the pressure and duration they are exposed to it. In the context of this standard, suitable breathing gases include air, oxygen and Enriched air/nitrox. NB. Pure Oxygen is NOT considered suitable for breathing in water. 427 Supplementary requirements: Requirements for material properties of component that are additional to the basic requirements, and that are intended to apply to components used for specific applications. 428 Surface compression chamber means a pressure vessel for human occupancy with means of controlling the pressure inside the chamber. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 1.3.5) 429 Survey: Signifies a systematic and independent examination of a diving system, materials, components or systems in order to verify compliance with the rules and/or statutory requirements. Surveys will be carried out on the vessel, at the construction or repair site as well as at sub-suppliers and other locations at the discretion of the Society, which also decides the extent and method of control. 430 Tentative rules: Provisional requirements and/or guidelines to which the Society reserves the right to make adjustments in order to obtain the intention reflected in the rules. 431 T op : Maximum operation time, i.e. the time from start of pressurization of the diver, until the diver is back to atmospheric conditions. 432 Transfer compartment: Compartment that is intended to be used for a lock-in or -out operation of divers between other compartments or outer area. Also known as TUP (Transfer Under Pressure) The diving system should be capable of allowing the safe transfer of a person under pressure from the diving bell to the surface compression chamber (and vice versa). (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey 2.2.7) 433 Transferable diving system: A diving system designed to be easily transferable in one or more units and which may be installed on-board a ship, barge or offshore platform for a short period of time not exceeding one year. A transferable diving system may be assembled from different units into a particular configuration suitable for a specific working operation. 434 Trunk: In the context of pressure vessels for human occupancy, trunk denotes the cylindrical spool-piece connecting separate chambers. The maximum length of these cylindrical trunks is considered to be 1400 mm. In the context of separation of fire resistant enclosures to Category A machinery spaces, a trunk is a small enclosed room defined in SOLAS Ch.II-2 Reg.9.2 Thermal and structural boundaries. 435 Type approval: is a procedure for plan approval. Type approval can be applied to products, groups of products, systems or retention survey. This procedure should normally be used for approval of standard designs. The type approval procedure may consist of the following elements: plan approval, initial survey, type testing and issue of a type approval certificate. The type approval procedure used by DNV is described in DNV Standard for Certification No Ultimate Tensile Strength (UTS): The measured ultimate tensile strength. 437 Umbilical means the link between the diving support unit and the diving bell and may contain surveillance, communication and power supply cables, breathing gas and hot water hoses. The hoisting and lowering strength member may be part of the umbilical. (IMO Code of Safety for Diving Systems Chapter 2 Design, Construction and Survey ) Umbilical (in DNV terms): A link between support vessel and the divers, or the diving wet-bell, which may contain gas hoses, hot water hose, power supply cables and communication cables. (See Sec.4) 438 Verification: A service that signifies a confirmation through the provision of objective evidence (analysis, observation, measurement, test, records or other evidence) that specified requirements has been met. 439 Wet bell = Open bell 440 Witnessing: Signifies attending tests or measurements where the surveyors verify compliance with agreed test or measurement procedures. 441 Work: All activities to be performed within relevant contract(s) issued by Owner, Builder or Manufacturer. 442 Working weight: of the basket or wet-bell shall be taken as the maximum weight of the fully equipped basket or wet-bell, including each fully equipped diver of 200 kg. The load from this weight applies to: a) launch and recovery in air, and b) launch and recovery submerged, combining the maximum negative buoyancy of the wire rope, umbilical and basket or wet-bell at maximum operating depth 443 Yield Stress: The measured yield tensile stress.