6.2.1 General
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code (2008) - Technical Code on Control of Emission of Nitrogen 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 (EIAPP Certificate) following an initial certification survey in accordance with 2.2.4; 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 When a marine diesel engine is designed to run within the applicable NOx emission limit, it is most likely that within the marine life of the engine, the NOx emission limit may be adhered to. The applicable NOx emission limit 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 applicable NOx emission limit.

  6.2.1.3 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 limit. Where the measurement of some operating values is required, the calibration of the equipment used for those measurements shall be in accordance with the requirements of appendix 4 of this Code.

  6.2.1.4 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 being in compliance with regulation 13 as applicable.

  6.2.1.5 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.

  6.2.1.6 For the purpose of assessing compliance with regulation 13, it is not always necessary to measure the NOx emissions to know that an engine, not equipped with an after-treatment device, is likely to comply with the applicable NOx emission limit. 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 applicable NOx emission limit, the engine may be re-certified without direct NOx measurement.

  6.2.1.7 For an engine equipped with a NOx reducing device, it will be necessary to check the operation of the device as part of the engine parameter check method.


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