4.3 Application of the engine family concept
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Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code - Technical Code on Control of Emission of Nitrous Oxides from Marine Diesel Engines - Chapter 4 - Approval for serially manufactured engines: engine family and engine group concepts - 4.3 Application of the engine family concept

4.3 Application of the engine family concept

  4.3.1 The engine family concept provides the possibility of reducing the number of engines which must be submitted for approval testing, while providing safeguards that all engines within the family comply with the approval requirements. In the engine family concept, engines with similar emission characteristics and design are represented by a parent engine within the family.

  4.3.2 Engines that are series-produced and not intended to be modified may be covered by the engine family concept.

  4.3.3 The selection procedure for the parent engine is such that the selected engine incorporates those features which will most adversely affect the NOx emission level. This engine, in general, shall have the highest NOx emission level among all of the engines in the family.

  4.3.4 On the basis of tests and engineering judgement, the manufacturer shall propose which engines belong to an engine family, which engine(s) produce the highest NOx emissions, and which engine(s) should be selected for certification testing.

  4.3.5 The Administration shall review for certification approval the selection of the parent engine within the family and shall have the option of selecting a different engine, either for approval or production conformity testing, in order to have confidence that the complete family of engines complies with the NOx emission limits.

  4.3.6 The engine family concept does allow minor adjustments to the engines through adjustable features. Marine engines equipped with adjustable features must comply with all requirements for any adjustment within the physically available range. A feature is not considered adjustable if it is permanently sealed or otherwise not normally accessible. The Administration may require that adjustable features be set to any specification within its adjustable range for certification or in-use testing to determine compliance with the requirements.

  4.3.7 Before granting an engine family approval, the Administration shall take the necessary measures to verify that adequate arrangements have been made to ensure effective control of the conformity of production.

Parent topic: Chapter 4 - Approval for serially manufactured engines: engine family and engine group concepts
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