SINOTRUK® Genuine -Expansion Tank Assembly- Spare Parts For SINOTRUK HOWO 70T Mining Dump Truck Part No.:AZ9112530333

Relevant Knowledge

The expansion tank can absorb excess coolant to minimize excess pressure in the engine cooling system. During water heating and expansion, the expansion tank helps to maintain the pressure rise to a minimum, reduce the flow impact of coolant, and helps to protect the engine cooling system from stress. In addition, the expansion tank is able to redistribute excess coolant into the system to ensure that it does not overflow.

The expansion tank usually has 1-2 interfaces at the top and bottom of the tank, depending on the model.

The air on the top of the water tank balances the air pressure. The air in the cooling system will return to the expansion tank from here.

Located at the bottom of the water tank is the water outlet, which replenishes coolant to the cooling system.

(The above refers to the usual design, and different car models may have different designs.)

If the working principle is explained clearly, then the function of the expansion tank is easy to say.

● Water gas separation, balanced pressure

The main components of coolant are ethylene glycol and water, so during engine operation, steam is generated in the heat dissipation system, and the pressure of the heat dissipation system constantly changes with the change of water temperature.

If the steam cannot be discharged and continues to circulate in the cooling pipeline, it will cause air resistance in the heat dissipation pipeline, resulting in poor heat dissipation and an increase in water temperature.

With expansion tank, steam from radiator and engine water channel can be separated and stored to balance system pressure.

However, gas can be compressed, and coolant cannot be compressed. Therefore, the expansion tank cannot be fully filled. When filling coolant, the liquid level cannot be higher than the upper limit of the expansion tank.

● Replenish return water

When the engine cylinder vibrates, bubbles will be generated in the coolant and water hammer (water hammer is a phenomenon of significant pressure fluctuations caused by a sharp change in liquid flow rate in a pressurized pipeline).

Under repeated action, the outer surface of the cylinder liner produces fatigue and gradually falls off, forming small pits and needle shaped holes, which is called pitting corrosion.

The water gas separation effect of expansion tank can reduce cavitation. In addition, under the make-up water of the expansion tank, the air mixing is reduced.

Therefore, the expansion tank shall not be too short of coolant, and the coolant level shall not be lower than the lower limit of the expansion tank.

Ensure the pressure of the heat dissipation system and ensure safe pressure relief

The cover of the expansion tank also has a lot of potential. In addition to sealing, it also has the function of pressure relief.

Sealing is to establish a certain pressure, increase the boiling point of the coolant, and improve the performance of the coolant.

Pressure relief refers to the opening of the pressure relief valve on the cover when the heat dissipation system pressure is too high, such as when a boiler is turned on, in order to timely release the system pressure and avoid serious losses.

In addition, the expansion tank can also facilitate the driver to check the life quality of coolant, and can visually observe whether there is a lack of coolant inside.

In addition, more and more trucks are now equipped with liquid level sensors in the expansion tank, which can prompt the driver through the dashboard in time when the coolant is in deficit, so as to avoid "boiling" due to lack of coolant.

After today's introduction, I believe you know how this humble expansion tank can protect our cooling system. Automotive design is a very rigorous discipline, and any component has its own value.