6.2.1 General
Clasification Society 2024 - Version 9.40
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 6 - Procedures for demonstrating compliance with NOx emission limits on board - 6.2 Engine parameter check method - 6.2.1 General

6.2.1 General

  6.2.1.1 Engines that meet the following conditions shall be eligible for an engine parameter check method:

  • .1 engines that have received a pre-certificate (EIAPP Certificate) on the test-bed and those that received a certificate (IAPP Certificate) following an initial certification survey; and

  • .2 engines that have undergone modifications or adjustments to the designated engine components and adjustable features since they were last surveyed.

  6.2.1.2 An engine parameter check method shall be conducted on engines, subject to 6.2.1.1, whenever there is a change of components and/or adjustable features of the engine that affect NOx emission levels. This method shall be used to confirm compliance with the NOx emission limits. Engines installed in ships shall be designed in advance for an easy check of components, adjustable features and engine parameters that affect NOx emission levels.

  6.2.1.3 In addition, when a diesel engine is designed to run within the prescribed NOx emission limits, it is most likely that, within the marine life of the engine, the NOx emission limits may be adhered to. The prescribed NOx emission limits may, however, be contravened by adjustments or modification to the engine. Therefore, an engine parameter check method shall be used to verify whether the engine is still within the prescribed NOx emission limits.

  6.2.1.4 Engine component checks, including checks of settings and an engine's operating values, are intended to provide an easy means of deducing the emissions performance of the engine for the purpose of verification that an engine with no, or minor, adjustments or modifications complies with the applicable NOx emission limits.

  6.2.1.5 The purpose of such checks is to provide a ready means of determining that an engine is correctly adjusted in accordance with the manufacturer's specification and remains in a condition of adjustment consistent with the initial certification by the Administration as compliant with regulation 13 of Annex VI.

  6.2.1.6 If an electronic-engine management system is employed, this shall be evaluated against the original settings to ensure that appropriate parameters are operating within "as-built" limits.

  6.2.1.7 For the purpose of assessing compliance with regulation 13 of Annex VI, it is not always necessary to measure the NOx level to know that an engine, not equipped with an after-treatment device, is likely to comply with the NOx emission limits. It may be sufficient to know that the present state of the engine corresponds to the specified components, calibration or parameter-adjustment state at the time of initial certification. If the results of an engine parameter check method indicate the likelihood that the engine complies with the NOx emission limits, the engine may be re-certified without direct NOx measurement.

  6.2.1.8 For engines equipped with after-treatment devices, it will be necessary to check the operation of the after-treatment device as part of the parameter check.


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