ABS has issued a guide to be applied to exhaust emission abatement systems fitted to ABS classed vessels and covering SOx scrubbers, SCR systems and EGR arrangements, together with Exhaust Emissions Monitoring Systems (EEMS) fitted in conjunction with the aforementioned emission abatement systems, or installed as an alternative Onboard NOx Verification Procedure in accordance with the Direct Measurement and Monitoring Method of the NOx Technical Code.
This Guide focuses on the safety and reliability aspects of exhaust emission abatement equipment that fall within the scope of traditional Classification requirements and is to be applied to those Exhaust Gas Cleaning (EGC) systems covering SOx scrubbers, SCR systems, and EGR arrangements.
The objective of this Guide is to provide criteria for the design, construction, installation, survey, and operation of machinery and equipment associated with exhaust emission abatement systems in order to minimize risks to the vessel, crew, and the environment.
The intent is that these requirements supplement the statutory emissions performance testing, survey, and certification requirements of IMO Regulations and Guidelines.
A special section provides requirements on the arrangements and system design for exhaust gas cleaning systems designed primarily for the removal of SOx emissions, or SOx scrubbers, as they are commonly known.
Plans and specifications covering the SOx scrubber arrangements are to be submitted and are, as applicable, to include:
- General arrangement of the SOx scrubber installation, layout, and systems
- Documentation detailing the SOx scrubber specification
- Analyses demonstrating compatibility of the scrubber with the fuel oil combustion units
- Hull plans showing the foundation and attachments to the vessel’s structure, including scantlings, welding details, and foundation details of principal components
- Documentation detailing the effect on Load Line and Stability of the exhaust emission abatement system
- Material specifications for the scrubber unit, pumps, valves, storage/process tanks, residue tanks, piping, distribution systems, separators, and associated components, including a corrosion assessment detailing the corrosive effect of system liquids, vapors, and gases on the materials used in the exhaust emission abatement system
- Arrangement and capacity of tanks for storage, chemicals, process washwater, exhaust gas cleaning residues, etc.
- Details of all piping systems, including details of piping and associated components, design pressures, temperatures, insulation, and drip trays, where applicable
- Descriptions and schematic diagrams for the control and monitoring systems, including set points for abnormal conditions and details of the location and positions where exhaust emission monitoring and washwater monitoring systems are to be located.
- Details of all electrical equipment installed for the SOx scrubber unit and associated systems, including computer-based systems
- Failure Modes and Effects Analysis (FMEA) to determine possible failures and their effects in the safe operation of the SOx scrubber
- Emergency shutdown arrangements
- SOx scrubber unit FMEA integration test report
- Operating and maintenance instruction manuals, including MSDS sheets and details for handling of hazardous and non-hazardous chemicals used in the SOx exhaust emission abatement system
- Testing procedures during installation and commissioning trials.
Further details may be found herebelow: