HJ/T 331-2006Specifications for environmental protection product. Catalytic converters for petrol vehicles (English PDF)

3.1 Catalytic converter

A device installed in the exhaust system of a gasoline vehicle to reduce the emissions of CO, HC compounds and NOx in the exhaust through oxidation and/or reduction reactions using a catalyst.

3.2 Original catalytic converter

Catalytic converters or catalytic converter assemblies installed during mass production for a certain vehicle type certification.

3.3 Alternative catalytic converter

Catalytic converters or catalytic converter assemblies that meet the requirements of this

Standard, other than the original catalytic converters defined in 3.2.

3.4 Catalytic converter conversion efficiency

The rate of change in the emission of a certain pollutant before and after the catalytic converter under specified operating conditions.

Where, i - it represents pollutants CO, HC compounds, and NOx, respectively.

3.5 Catalytic converter ignition temperature

The inlet gas temperature of a catalytic converter when its conversion efficiency for a certain pollutant reaches 50%.

4.1 Classification

Catalytic converters can be divided into two categories based on their application market.

a) OEM catalytic converter. a catalytic converter that is supplied to a newly manufactured vehicle; this refers to an original equipment catalytic converter.

b) Catalytic converter for aftermarket use. a catalytic converter intended for sale on the market as replacements for damaged or malfunctioning original catalytic

Catalytic converter conversion efficiency

Emissions of pollutant i before the catalytic converter - Emissions of pollutant i after the catalytic converter

Emissions of pollutant i before the catalytic converter converters. This includes replacement catalytic converters and original replacement catalytic converters.

4.2 Naming

The naming and model numbering of catalytic converters should, in principle, follow

QC/T 265.Alternatively, they can be named and numbered according to the requirements of the automobile/engine manufacturer, but the naming and numbering must include the manufacturer's information.

5.1 General requirements

5.1.1 Catalytic converters should be permanently marked with the manufacturer's name or trademark, as well as the catalytic converter model and the direction of the inlet and outlet.

5.1.2 The design, manufacture, and installation of catalytic converters should ensure that vehicles comply with all national standards.

5.1.3 The design, manufacture, and installation of catalytic converters should be designed to prevent corrosion and oxidation that may occur during vehicle use.

5.1.4 The design and manufacture of the catalytic converter shall ensure that, during the sealing test as described in 6.2.1, the pressure drop shall not exceed 5 kPa. During installation, the interfaces of the catalytic converter shall be sealed.

5.1.5 The replacement catalytic converter should be installed in the same location as the original catalytic converter. The vehicle's ground clearance must not be reduced.

The position of the oxygen sensor in the exhaust pipe should not be altered.

5.1.6 Catalytic converters should be equipped with thermal insulation measures to ensure safe operation.

5.1.7 Catalytic converters shall be subjected to ignition temperature test and air-fuel ratio characteristic test in accordance with 6.2.3.

5.1.8 The catalytic converter shall be accompanied by the following information.

a) Carrier structure, materials, and manufacturer;

b) Carrier quantity, shape, size, volume, and pore density;

c) Precious metal content and proportion;

d) Gasket type and manufacturer;

e) Catalytic converter packaging method.

5.2 Mechanical performance requirements

5.2.1 After the product undergoes the axial thrust test (6.2.5.1), thermal life and water quenching test (6.2.5.2), and longitudinal thermal vibration test (6.2.5.3), the relative displacement of the carrier shall not exceed 3 mm according to the measurement in

6.2.5.4; the cumulative axial displacement of the carrier relative to its original position shall also not exceed 6 mm.

5.2.2 When the product undergoes thermal life and water quenching tests according to

6.2.5.2 and longitudinal thermal vibration tests according to 6.2.5.3, and then undergoes a sealing test according to 6.2.1, the pressure drop shall not exceed 5 kPa.

5.3 Exhaust emission performance requirements

5.3.1 Original catalytic converter

5.3.1.1 For original catalytic converters installed on vehicles with a maximum gross

vehicle weight not exceeding 3500 kg, after an 80000 km durability test according to the method in Annex G of GB 18352.2, the vehicle exhaust emissions shall meet the requirements of Type I test in GB 18352.2 or GB 18352.3.

5.3.1.2 For original catalytic converters installed on automobiles with a maximum gross

vehicle weight greater than 3500 kg, after the catalytic converter undergoes a 100 h rapid aging test as per 6.2.4, the engine emissions should meet the corresponding emission limits when tested according to GB 14762.

5.3.2 Catalytic converter for accessories

5.3.2.1 For catalytic converters used in components installed on automobiles with a

maximum gross vehicle weight not exceeding 3500 kg, after undergoing a 50000 km durability test or a 100-h rapid aging test according to 6.2.4, and then installed on a test vehicle, the vehicle exhaust emissions should meet the corresponding emission limits when undergoing a Type I test according to GB 18352.2 or GB 18352.3.In this case, the test results do not need to be multiplied by a degradation factor.

5.3.2.2 For catalytic converters used in automobiles with a maximum gross vehicle

weight greater than 3500 kg, after the catalytic converter undergoes a 100-h rapid aging test as per 6.2.4, the engine emissions shall meet the corresponding emission limits when tested according to GB 14762.

5.3.2.3 Under both conditions 5.3.2.1 and 5.3.2.2, the conversion efficiency of the

catalytic converter for CO, HC compounds, and NOX should be greater than 70%.

5.4 Durability requirements

5.4.1 For original catalytic converters, under normal vehicle use and maintenance

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