JB/T 11880.8-2014Diesel Engines - Selective Catalytic Reduction (SCR) Systems - Part 8: Selective Catalytic Reduction Converters (English PDF)

4.2 General requirements

4.2.4 This part requires all calculation results to be rounded off to two significant digits in accordance with the provisions of GB/T 8170-2008.

4.3 Airtightness

When the SCR converter is tested for tightness according to the provisions of 5.1, its pressure drop shall not exceed 5 kPa.

4.4 Mechanical properties

4.4.1 After the SCR converter is subjected to the axial thrust test according to the provision of 5.2.1 and the thermal life and water quenching test according to the provision of 5.2.2, the measured relative displacement of the carrier shall not be greater than 3 mm; the cumulative axial displacement of the carrier relative to the original position shall not be greater than 6 mm.

4.4.2 After the SCR converter is subjected to the thermal life and water quenching test according to the provision of 5.2.2, when the tightness test is performed according to 5.1, the pressure drop shall not exceed 5 kPa and the load shall not be broken.

4.4.3 After the SCR converter is subjected to the random thermal vibration test under the (40000 ± 400) h-1 space velocity condition as specified in Table 1, there shall be no cracks, desoldering, carrier chipping, etc. in any part of the SCR converter.

5.1 Tightness test

Apply (30 ± 5) kPa pressure air in the SCR converter. Determine the pressure drop within 30 s.

5.2 Mechanical performance test

5.2.1 Axial thrust test

Under normal temperature, uniformly apply an axial thrust of 1500 N on the end face of the carrier, to detect the axial displacement.

5.2.2 Thermal life and water quenching test

It is performed in accordance with the provisions of GB/T 18377.

5.2.3 Vibration test

Install the SCR converter on the vibration bench according to the state of use on the vehicle. The performance of the vibration test bench meets the requirements listed in Table 1. The support for installing the SCR converter shall simulate the installation state of the SCR converter on the vehicle; meanwhile it shall have sufficient strength and rigidity. According to the installation state of the SCR converter, perform the vibration test according to the requirements specified in Table 1. After completing the vibration test, check whether the SCR converter has cracks, desoldering, carrier chipping or other damage. The SCR converter before and after vibration shall undergo a tightness test and be disassembled, to measure the axial displacement of the carrier before and after the test.

5.3 Conversion efficiency test

The new SCR converter shall be pre-treated before the conversion efficiency test. The pretreatment can be carried out according to the following conditions (1) or (2):

- Condition (1): At the inlet temperature of (500 ± 25) °C of the SCR converter and the space velocity of (40000 ± 400) h-1, make it running for 5 h;

- Condition (2): Light-duty vehicles shall be performed in accordance with the provisions of C.5.3 of GB 18352.3-2005, and heavy-duty vehicles shall be - There are no specific requirements for the font and size of the permanent marking, as long as it can be identified.

7.2 Packaging

7.2.1 Precautions for packaging

Considerations for product packaging:

a) Requirements for moisture-proof, vibration-proof and dust-proof;

b) Meet the relevant requirements of transportation and handling;

c) There are temporary protective measures (such as shields, sheaths, etc.) at the connector of the product, to prevent the inner cavity from being contaminated;

d) The matching parts on the ferrous metal parts of the product before packaging shall have temporary anti-rust protection measures.

7.2.2 Packing carton

7.2.2.1 The packing carton shall be firm; the product shall not move in the carton, to avoid damage to the product during transportation.

7.2.2.2 The technical documents supplied with the product in the packing carton shall include: packing list, product exit-factory certificate, product specification. The content of the product exit-factory certificate shall include:

a) Product name and model;

b) Product exit-factory number (batch number);

c) The name and trademark of the manufacturer:

d) Inspection conclusion;

e) Inspector's signature;

f) Date of inspection.

7.2.2.3 The outside of the packing carton shall be marked of the following:

a) Registered trademark or product quality certification mark, barcode;

b) Product name and model;

c) The name, address, zip code and telephone number of the manufacturer; […]