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DNV-OS-D101 Marine and Machinery Systems and Equipment
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CHAPTER 3
Certification and Classification
Ch.3
SECTION 1
Certification and ClassificationCh.3 Sec.1
A. General
Ch.3 Sec.1
A 100 General
Ch.3 Sec.1 A
101 As well as representing DNV's recommendations on
safe engineering practice for general use by the offshore industry,
the offshore standards also provide the technical basis for DNV
classification, certification and verification services.
Ch.3 Sec.1 A
102 A complete description of principles, procedures, applicable
class notations and technical basis for offshore classification
is given by the DNV offshore service specifications for classification,
see Table A1.
Ch.3 Sec.1 A
| Table A1 DNV Offshore
Service Specifications |
| No. | Title | DNV-OSS-101 | Rules for Classification of Offshore Drilling
and Support Units | | DNV-OSS-102 | Rules for Classification of Floating Production,
Storage and Loading Units | | DNV-OSS-103 | Rules for Classification of Floating LNG/LPG
Production, Storage and Loading Units | |
Ch.3 Sec.1
A 200 Certification and classification
principles
Ch.3 Sec.1 A
201 Marine and machinery systems and equipment will be certified
or classified based on the following main activities:| — | design verification |
| — | equipment certification |
| — | survey during construction and installation, and |
| — | survey during commissioning and start-up. |
Ch.3 Sec.1
A 300 Assumptions
Ch.3 Sec.1 A
301 Any deviations, exceptions and modifications to the design
codes and standards given as recognised reference codes shall be
documented and approved by DNV.
Ch.3 Sec.1 A
302 Aspects of the design and construction provisions of this
standard (Ch.2) which shall be specially considered, agreed upon,
or may be accepted are subject to DNV approval when the standard
is used for classification purposes.
Ch.3 Sec.1 A
303 DNV may accept alternative solutions found to represent an
overall safety level equivalent to that stated in the requirements
of this standard.Ch.3 Sec.1
B. Documentation Requirements
Ch.3 Sec.1
B 100 General
Ch.3 Sec.1 B
101 Documentation requirements shall be in accordance with the
NPS DocReq (DNV Nauticus Production System for documentation requirements)
and DNV-RP-A201.Ch.3 Sec.1
C. Certification of Materials and
Components
Ch.3 Sec.1
C 100 General
Ch.3 Sec.1 C
101 Certification is a conformity assessment normally including
both design and production assessment.The production assessment includes inspection and testing
during production and/or of the final product.
Ch.3 Sec.1 C
102 Components shall be certified consistent with their function
and importance for safety. The principles of categorisation of component
certification are given in the relevant offshore service specifications,
see Table A1.
Ch.3 Sec.1
C 200 Certificate types
Ch.3 Sec.1 C
201 DNV defines three levels of documentation depending on importance
of equipment and experience gained in service as given in 202.
Ch.3 Sec.1 C
202 Test report (TR) is
a document signed by the manufacturer which states :| — | conformity with the rule requirements |
| — | that testing is carried out on samples from the current
production of equal products. |
The manufacturer is to have a quality system that is suitable
for the kind of certified product. The surveyor is to check that
the most important elements of this quality system are implemented
and may carry out random inspection at any time. The products shall
be marked to be traceable to the test report.
Works Certificate (W) is
a document signed by the manufacturer which states:
| — | conformity with the rule or
standard requirements |
| — | that the tests are carried out on the certified product
itself |
| — | that the tests are made on samples taken from the certified
product itself |
| — | that the tests are witnessed and signed by a qualified
department. |
The manufacturer is to have a quality system that is suitable
for the kind of certified product. The surveyor is to check that
the most important elements of this quality system are implemented
and may carry out random inspections at any time. The component
shall be marked to be traceable to the work certificate.
DNV Product Certificate (NV) is
a document signed by a DNV surveyor which states:
| — | conformity with the rule requirements |
| — | that the tests are carried out on the certified product
itself |
| — | that the tests are made on samples taken from the certified
product itself |
| — | that the tests are made in the presence of a DNV surveyor
or in accordance with special agreements. |
The product shall be stamped with a special NV-stamp traceable
to the certificate.
Guidance note:
The terms NV Certificate, Works Certificate, and Test Report
used here refer to a product certificate rather than a material
certificate.
A DNV Product Certificate (NV) may be delivered with material
certified to a lower level than a DNV Material Certificate (NV)
or ISO 10474 Certificate Type 3.2. The level of material certification
is agreed as part of the certification process.---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
Ch.3 Sec.1
C 300 Categorisation
of equipment and components
Ch.3 Sec.1 C
301 Equipment is categorised based on safety and complexity considerations.
The category of equipment will determine the scope of the certification
activity and the certificate type to be issued.
Ch.3 Sec.1 C
302 Equipment may be categorised into two main categories, Category
I, for which a DNV Product Certificate (NV) is required or Category
II, for which manufacturer certification (W or TR) will be accepted.
Ch.3 Sec.1 C
303 Category I is subdivided into three subcategories depending
on whether or not design review is carried out or whether an extensive
fabrication survey is required. Ref Table C1
Ch.3 Sec.1 C
304 Category II is subdivided into two subcategories depending
on whether the manufacturer documentation required is based on a
sample of similar products or the actual product to be delivered.
Ref Table C1.Ch.3 Sec.1 C
Table C1 Equipment
categorisation | | Cat IA | Cat IB | Cat IC | Cat IIA | Cat IIB | Scope | D S2 R2 | D S1 R2 | S1 R2 | R2 | R1 | | Certificate / Document | NV | NV | NV | W | TR | | D: | Design review | | S1: | Witness of final testing of completed product | | S2: | Survey during construction and witness of final testing of
completed product | | R1: | Review of manufacturers documentation (typical for product) | | R2: | Review of manufacturers documentation (specific to product) |
| | |
Ch.3 Sec.1
C 400 Certification requirements under
DNV-OS-D101
Ch.3 Sec.1 C
401 Certification requirements for miscellaneous mechanical components
are given in Table C2.Ch.3 Sec.1 C
| Table C2 Certification
of miscellaneous machinery and mechanical components |
| Item | Certification category | Jacking machinery | IA | | Turret bearings | IA | | Boiler | IA | | Condenser | IIA | | Boiler heat exchanger | IA | | Pumps for boiler | IC | | Boiler PSV | IC | | Boiler spark arrestor | IIB | | Winches | IA | | Hydraulic Cylinders pD > 20000 1) | IA | | Hydraulic Cylinders pD £ 20000 | IIA | | Compressor | 2) | - Hydraulic
cylinders for cleating and manoeuvring of watertight doors and hatches
shall be delivered with certificate of category IA regardless of
pressure and size. Cleating cylinders where the locking mechanism
is placed inside the cylinder are to be type approved.
- Compressors to be certified in accordance with Ship
Rules Pt.4 Ch.5 Sec.4.
p =
design pressure (bar)
D = internal diameter
of cylinder tube (mm) | |
Ch.3 Sec.1 C
402 Piping and piping components are to be delivered with material
certification in accordance with Ch.2 Sec.2
Table B4. Where the requirement calls for witness by 3rd party (Certificate Type
3.2) this shall be carried out by DNV.
Ch.3 Sec.1 C
403 Certification requirements for pressure vessels are given
in Table C3.Ch.3 Sec.1 C
| Table C3 Categories
for pressure containing equipment and storage vessels 1) |
| Property | Conditions | Category |
| I 2) | II |
| Pressure |
| | X |
| X | |
| Vacuum or external pressure | X | |
| Medium | Steam | X | |
| Toxic fluid | X | |
| Thermal oil | X | |
| Liquids with flash point below 100 °C | X | |
| Flammable fluids with T > 150 °C | X | |
| Other fluids with T > 220 °C | X | |
| Compressed air/gas PV ³ 1.5 | X | |
| Material | sy 345
MPa (50000 psi) or st 515
MPa (75000 psi) | X | |
| Where impact testing is required. | X | |
- Free standing structural storage tanks will be specially considered
based on stored medium, volume and height. These may be designed
according to the requirements of DNV-OS-C101.
- Normally category IA, however, limited class survey
may be agreed upon with DNV based on manufacturer's QA/QC
system, manufacturing survey arrangement (MSA) and fabrication methods.
| P | = | internal design pressure in bar | | Di | = | inside diameter in mm | | V | = | volume in m3 | | T | = | design temperature | | sy | = | specified yield strength | | st | = | specified ultimate tensile strength |
|
Ch.3 Sec.1 C
404 Certification requirements for steering and propulsion components
are given in Table C4.Ch.3 Sec.1 C
| Table C4 Certification
of components for steering and propulsion systems |
| Item | Certification category | Thruster including receptacles | IA | | Propeller | IA | | Steering gear | IA | | Rudder | IA | | Diesel engine | IA | | Gas turbine | IA | |
Ch.3 Sec.1 C
405 For equipment in piping systems serving essential and important
functions on self-propelled units equipment as listed in DNV Rules
for Classification of Ships Pt.4 Ch.6 Sec.5 shall be delivered with
a NV Certificate.
Ch.3 Sec.1 C
406 For equipment on other installations, certification in accordance
with Table C5 will be required for the listed equipment.
Ch.3 Sec.1 C
407 Electrical equipment should be certified in accordance with
DNV-OS-D201 Ch.3 Sec.1 C400.Ch.3 Sec.1 C
Table C5 Certification
of components in marine piping systems | Item | Certification
category | Piping
system items for main engine or main power | | Fuel oil transfer pump | IC | | Lube oil pump | IC | | Cooling system pump unit | IC | | Lube oil heat exchanger | IC | | Fuel oil heat exchanger | IC | | | | | Valves | | Valves for sea inlet or discharge with DN >100
mm | IC | | Valves with DN >100 mm and p>16
bar | IC | | Non-standard valves | IB | | | | | Compressed
air systems | | Starting air compressors | IC | | Pressure relief valves | IIA | | | | | Ballast
system | | Ballast pumps | IC | | | | | Bilge
and drain system | | Bilge pumps | IC | | Bilge ejectors | IIA | | Strainers | IIB | | Strums and rose boxes | IIB | | | | | Air and
sounding systems | | Air vent heads | IB | | Tank level indicators | IIA | | Sounding control panel | IB | | Striking plates | IIB | | Sounding rods | IIB | | | | | Hydraulic
control of safety critical valves etc. | | Hydraulic control panel | IB | | Pumps in hydraulic control system | IC | | Hydraulic power pack | IIA | | Accumulators (pV > 150 kNm) | IB | | Accumulators (others) | IIA | | Tanks for hydraulic fluid | IIB | | |
Ch.3 Sec.1 C
Table
C6 Certification of control systems | Item | Certification category | Steering and propulsion systems (if relevant) | IC | Main engine or main power | IC | Ballast system | IC | Bilge system | IC | Air and sounding (level monitoring) | IC | Control of safety critical valves (hydraulically
or pneumatically operated not covered by other certified control
systems) | IC | Jacking machinery (if installed) | IC | Boiler (if installed) | IC | Winches (dependent on class notation, e.g.
POSMOOR) | IC | Leak detection system (if relevant for unit,
ref. also Ch.2 Sec.3 F500) | IC | | | | | | | | | | | |
Ch.3 Sec.1
D. Survey During Construction
Ch.3 Sec.1
D 100 General
Ch.3 Sec.1 D
101 Subsection D describes surveys during construction of marine
and machinery systems and components.
Ch.3 Sec.1 D
102 General requirements for surveying during construction are
stated in the relevant DNV offshore service specification for classification,
see Table A1. Ch.3 Sec.1
D 200 Quality assurance and quality
control
Ch.3 Sec.1 D
201 The contractors shall operate a quality management system
applicable to the scope of their work. The system shall be documented
and contain descriptions and procedures for quality critical aspects.
Ch.3 Sec.1 D
202 Contractors who do not meet the requirement in 201 will be
subject to special consideration in order to verify that products
satisfy the relevant requirements.
Ch.3 Sec.1 D
203 The contractors shall maintain a traceable record of non-conformities
and corrective actions and make this available to the DNV surveyor
on request.Guidance note:
Contractors are encouraged to obtain ISO 9000 series quality
system certification through DNV Accredited Quality System Certification
services.---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
Ch.3 Sec.1
D 300 Materials
Ch.3 Sec.1 D
301 Welded pipes may be accepted as seamless pipes only where
supplied by a DNV approved manufacturer for the production of such
pipes.
Ch.3 Sec.1 D
302 Grey cast iron shall only be accepted for hydraulic piping
systems after special consideration on a case by case basis.
Ch.3 Sec.1 D
303 Use of nodular cast iron for piping shall be subject to special
DNV approval on a case by case basis.
Ch.3 Sec.1 D
304 Design conditions for plastic pipes containing media other
than water, shall be supplied to DNV for approval.
Ch.3 Sec.1 D
305 Electrically conductive piping for use in gas hazardous areas
shall be DNV type approved (See Ch.2 Sec.2 B506).Ch.3 Sec.1
D 400 Welding and welder qualification
Ch.3 Sec.1 D
401 Approval of welders shall be in accordance with DNV-OS-C401
or the applied design code.
Ch.3 Sec.1 D
402 Welders already approved to another corresponding code than
the design code may be accepted if properly documented.
Ch.3 Sec.1 D
403 WPS shall be approved by DNV.
Ch.3 Sec.1 D
404 The extent of the welding procedure test shall be agreed upon
with DNV before the work is started.
Ch.3 Sec.1 D
405 A welding production test (WPT) may be required by the surveyor
during fabrication to verify that the produced welds are of acceptable
quality.
Ch.3 Sec.1 D
406 Welding repairs shall be performed according to an repair
procedure approved by DNV.
Ch.3 Sec.1 D
407 Socket welded joints and slip on sleeves shall be subject
to special DNV approval on a case by case basis.
Ch.3 Sec.1 D
408 Local PWHT may be performed on simple joints when following
an approved procedure. The procedure shall be approved by DNV.
Ch.3 Sec.1 D
409 The heat treatment procedure in connection with forming and/or
welding shall be approved if not covered by the applied code or
standard.
Ch.3 Sec.1 D
410 The heat treatment procedure in connection with pipe bending
shall be approved if not covered by the applied code or standard.
Ch.3 Sec.1 D
411 Omission of heat relieving treatment for C and C-Mn steels
up to 30 mm thickness shall be subject to special DNV approval.
Ch.3 Sec.1 D
412 Magnetic particle inspection (MPI) is the preferred method
for detection of surface defects, however the liquid penetrant method
may be used as an alternative, subject to DNV's acceptance
in each case.
Ch.3 Sec.1 D
413 Piping systems shall be cleaned (e.g. by flushing, retro-jetting,
chemical cleaning etc.) to remove debris or foreign bodies prior
to start-up of sensitive equipment like pumps, compressors, isolation
valves etc. The procedure and acceptance criteria shall be agreed
with the surveyor.Ch.3 Sec.1
E. Survey During Installation and
Commissioning
Ch.3 Sec.1
E 100 General
Ch.3 Sec.1 E
101 Commissioning shall be in accordance with submitted procedures
reviewed by DNV in advance of the commissioning. Commissioning shall
be witnessed by a surveyor and is considered complete when all systems, equipment
and instrumentation are operating satisfactorily. The intention
of DNV's involvement in evaluation of commissioning procedures
and attending commissioning of systems is to ensure that relevant
equipment/systems is functioning in compliance with relevant
Rules and Standards. Ch.3 Sec.1
E 200 Mechanical completion
Ch.3 Sec.1 E
201 Before commissioning of systems starts, all items of pipework
and equipment shall be checked for compliance with approved documentation
and commissioning procedures. Ch.3 Sec.1
E 300 Functional testing
Ch.3 Sec.1 E
301 During commissioning, the systems shall be functionally tested,
as practicable in accordance with reviewed procedures.
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