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Code of Federal Regulations (Last Updated: July 5, 2024) |
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Title 40 - Protection of Environment |
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Chapter I - Environmental Protection Agency |
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SubChapter C - Air Programs |
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Part 91 - Control of Emissions from Marine Spark-Ignition Engines |
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Subpart D - Emission Test Equipment Provisions |
Appendix A to Subpart D of Part 91 - Tables
Latest version.
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Appendix A to Subpart D of Part 91 - Tables
Table 1 - Symbols Used in Subparts D and E
Symbol Term Unit AYM Final weighted emission test results g/kW-hr C3 H8 Propane CB Concentration of emission in background sample ppm CD Concentration of emission in dilute sample ppm CO Carbon monoxide CO2 Carbon dioxide conc Concentration (ppm by volume) ppm DX Density of a specific emission (XX) g/m3 DXX Volume concentration of a specific emission (XX) on a dry basis percent DF Dilution factor of dilute exhaust D1 Water vapor mixture concentration percent f Engine specific parameter considering atmospheric conditions GAIRD Intake air mass flow rate on dry basis kg/h GFuel Fuel mass flow rate kg/h GP Analyzer standard operating pressure Pa Gs Mass of carbon measured during a sampling period g H Absolute humidity (water content related to dry air) gr/kg H2 Hydrogen i Subscript denoting an individual mode IT Indicated torque N-m K Wet to dry conversion factor KH Humidity correction factor KV Calibration coefficient for critical flow venturi MX Molecular weight of a specific molecule(XX) g/mole mass Pollutant mass flow g/h MFUEL Mass of fuel consumed during a sampling period g N Pump revolutions during test period revs N2 Nitrogen NO Nitric oxide NO2 Nitrogen dioxide NOX Oxides of nitrogen O2 Oxygen O2 I Oxygen concentration of the burner air percent P Absolute pressure kPa PAUX Declared total power absorbed by auxiliaries fitted for the test kW PB Total barometric pressure (average of the pre-test and post-test values) kPa Pdew Test ambient saturation vapor pressure at the dew point kPa Pe Absolute pump outlet pressure kPa PED Pressure drop between the inlet and throat of metering venturi kPa Pi Pi = PM, i + PAUX,i PM Maximum power measured at the test speed under test conditions kW PP Absolute pump inlet pressure kPa PPI Inlet pressure depression of venturi or pump kPa PPO Pressure head at CVS pump outlet kPa Ps Dry atmospheric pressure kPa PV Absolute venturi inlet pressure kPa Pwb Saturated vapor pressure Pa QC Volumetric flow rate of dilute exhaust through CVS at STP m3/hr QS Gas flow rate m3/min RSTP Ideal gas constant at STP m3/mole R2 Fuel carbon weight fraction g/g STP Standard temperature and pressure t Elapsed time for test period sec. T Absolute temperature at air inlet °C Ta Ambient temperature °C TEI Air temperature in to metering venturi or flowmeter °C TK Absolute temperature K TP Absolute pump inlet temperature °C TPI Air temperature at CVS pump inlet °C TPO Air temperature at CVS pump outlet °C TV Absolute venturi inlet temperature °C VO Pump flow m3/rev W Average mass flow of emissions g/hr WX Mass rate of specific emission (XX) g/hr WXX Volume concentration in exhaust of specific emission (XX) on wet basis ppm, ppmC, % WF Weighing factor Z1 Water concentration percent α Fuel specific factor representing the hydrogen to carbon ratio Table 2 - Measurement Accuracy Calibration Frequency
No. Item Permissible deviation from reading1 Calibration frequency non-idle idle 1 Engine speed ±2% ±2% Monthly. 2 Torque ±5% Monthly. 3 Fuel consumption ±1% ±5% Monthly. 4 Air consumption ±2% ±5% As required. 5 Coolant temperature ±2 °C Same As required. 6 Lubricant temperature ±2 °C Same As required. 7 Exhaust back pressure ±5% Same As required. 8 Inlet depression ±5% Same As required. 9 Exhaust gas temperature ±15 °C Same As required. 10 Air inlet temperature (combustion air) ±2 °C Same As required. 11 Atmospheric pressure ±0.5% Same As required. 12 Humidity (combustion air) (relative) ±3.0% Same As required. 13 Fuel temperature ±2 °C Same As required. 14 Temperature with regard to dilution system ±2 °C Same As required. 15 Dilution air humidity ±3% absolute Same As required. 16 HC analyzer ±2%2 Same Monthly. 17 CO analyzer ±2%2 Same Monthly. 18 NOX analyzer ±2%2 Same Monthly. 19 NOX converter check 90% Same Monthly. 20 CO2 analyzer ±2%2 Same Monthly. Table 3 - Test Fuel Specifications
Item Property Tolerance Procedure (ASTM)1 Sulfur, ppm max 1000 D 2622 Benzene, max. percent 1.5 D 3606 RVP, psi 8.6 ±0.6 D 323 Octane, R + M/2 89.9 ±3.1 D 2699
D 2700IBP, °C 32.8 ±11.0 D 86 10% point, °C 53.3 ±5.5 D 86 50% point, °C 101.7 ±8.3 D 86 90% point, °C 160.0 ±11.1 D 86 End Point, max. °C 212.8 D 86 Phosphorus, g/l, max 0.02 D 3231 Lead, g/l, max 0.02 Manganese, g/l, max 0.004 Aromatics, max. percent 35 D 1319 Olefins, max. percent 10 D 1319 Saturates, percent remain D 1319