Maintenance and replacement

Main functions

Common faults

Notes

Urea Filters

Urea filter is an important component in the selective catalytic reduction (SCR) system of diesel vehicles. It is mainly used to filter impurities in the automotive urea (commonly known as "Ad-Blue" or "DEF") to ensure the purity of the urea, thereby ensuring the normal operation of the SCR system and effectively reducing the emission of nitrogen oxides (NOx).

1. Filter impurities; Urea may be mixed with impurities such as particles and dust during production, storage and filling. The urea filter can effectively filter these pollutants to prevent them from blocking the injection system.

2. Protecting the SCR system; Clean urea can protect key components such as urea pumps and nozzles and extend their service life.

3. Ensuring emission compliance; By filtering impurities, the urea filter ensures the normal operation of the SCR system, reduces nitrogen oxide emissions, and meets environmental protection requirements.

The urea filter is usually installed between the urea tank and the urea pump. Impurities will be filtered by the urea filter before entering the SCR system. The filtered urea is injected into the exhaust pipe, where it reacts chemically with nitrogen oxides in the exhaust gas to produce harmless nitrogen and water.

   - Used to filter particles and impurities in urea.

   - Commonly used in light and medium-duty diesel vehicles.

2. Integrated urea filter

   - Integrated with urea pump or urea tank. The structure is compact.

   - Commonly used in heavy-duty commercial vehicles.

3. Heated urea filter

   - Built-in heated device to prevent urea from crystallization in low temperature environment.

   - Suitable for cold areas.

The replacement of urea filter varies according to the vehicle model, environment and urea quality. Generally recommended;

   - Light-duty vehicles; Replace every 50,000 to 100,000 kilometers.

   - Heavy-duty commercial vehicles; Replace every 20,000 to 50,000 kilometers.

Please refer to the user manual or manufacturer's recommendations for specific replacement .

1. Filter blockage

   - Faults; SCR system alarms, engine power decreases, and emission fault light on.

   - Cause; Long-term non-replacement, excessive accumulation of impurities.

2. Urea crystallization

   - Faults; Filter or pipeline blockage; insufficient urea injection.

   - Cause; Urea crystallization in low temperature environment; or use of low-quality urea.

3. Leakage

   - Faults; Urea leakage; SCR system failure.

   - Cause; the seal is damaged or installed improperly.

1.Choose high-quality filters; low-quality filters with poor performance may damage the SCR system.

2. Regular replacement; Replace the filter in time according to the vehicle usage and urea quality.

3. Use qualified urea; Inferior urea may cause filter blockage or crystallization, affecting the operation of the SCR system.

4. Maintenance in low temperature environment; In cold areas, check whether the filter and pipeline are crystallized, and use a heated filter if necessary.

Working principles

Types