The water pipe of automobile circulating pump needs to have the following characteristics:

1. High temperature resistance: The water pipe of the circulating pump needs to be able to withstand the working conditions in high temperature environment, so as to ensure that it will not be softened, deformed or broken due to high temperature when the engine is running.

2. Pressure resistance: The water pipe needs to be able to withstand the pressure inside the engine cooling system to ensure that there will be no water leakage or burst when the system works.

3. Corrosion resistance: The water pipe needs to have good corrosion resistance, which can resist the corrosion caused by chemicals in the coolant and prolong the service life of the water pipe.

4. Good flexibility: The water pipe needs to have certain flexibility, which can adapt to the installation requirements of different angles and positions, and ensure tight connection and no water leakage.

5. Good sealing performance: The water pipe should be able to provide good sealing performance to ensure that the cooling liquid will not leak and keep the cooling system in normal working condition.

6. Wear resistance: The water pipe needs to have certain wear resistance, which can resist the wear caused by external environment and vibration and prolong the service life of the water pipe.

7. Safety performance: The water pipes should meet the relevant safety standards and regulations to ensure that there will be no safety problems such as water pipe rupture or water leakage during vehicle driving.

To sum up, the water pipe of automobile circulating pump needs to have the characteristics of high temperature resistance, pressure resistance, corrosion resistance, flexibility, sealing, wear resistance and safety to ensure the normal operation of the cooling system and the safety performance of the vehicle. When selecting water pipes, it is recommended to choose products with reliable quality and meeting the standard requirements, and regularly check and maintain the water pipes to ensure their normal work and safety and reliability.