AdBlue (a 32.5% high-purity urea aqueous solution) is the key medium for reducing exhaust gases in the SCR system. If ordinary hoses are used, metal ions or plasticizers will seep into the liquid, contaminating the catalyst and dosing pump. Therefore, special hoses must be selected to ensure chemical purity and system safety.

Hose Types

Delivery hose: Connects the storage tank to the vehicle, multi-layer structure, resistant to dragging, high pressure and compression, with a smooth inner lining to reduce the risk of turbulence and crystallization.

Hose reel: Used for storing and protecting hoses, preventing mechanical damage, grease contamination and sharp bends from causing wear. Suitable for frequent refueling scenarios.

Key material requirements

Materials in contact with liquids must not contain zinc, copper, aluminum, cast iron or unalloyed brass. Otherwise, impurities will be released, precipitates will form, and the sealing of the metering pump will be damaged. The inner tube should be made of peroxide-cured rubber or a special polymer to prevent chemical extraction. The end fittings should be selected from stainless steel SS316 or virgin polypropylene.

Selection Skills

Work pressure: For pneumatic pump systems, use 3-5 bar hoses; for industrial high-pressure systems, it should be ≥ 10 bar.

Temperature range: The freezing point of AdBlue is -11℃. Beyond 30℃, it is prone to deterioration. For outdoor use, insulation or heating is required.

Inner diameter (ID): Heavy-duty trucks recommend 3/4 inch, while light vehicles use 1/2 inch to ensure flow matching.

Connector compatibility: Use non-corrosive metal or plastic connectors to avoid damaging the inner lining.

Maintenance Points

Daily: Visual inspection of the pipe wall for scratches, bulges or deformations.

Weekly: Rinse the pipeline with warm deionized water to prevent crystallization accumulation.

Monthly: Check the joint seals to ensure no leakage or white deposits.

Continuous: Avoid direct sunlight to prevent UV aging of the inner urea layer and the outer sheath.

Compliance and Summary

It is essential to select hoses that comply with ISO 22241 and DIN 70070 standards. This is the prerequisite for ensuring fluid purity and the lifespan of the SCR device. Reasonably matching pressure, temperature, and diameter, combined with regular maintenance and storage in a dark place, can effectively extend the hose lifespan and reduce the risk of system failures. Special reels and compliant materials are key aids for on-site management. Choosing the right hose is protecting your catalyst and pump valve investment.