Working principle of pressure stabilizing expansion tank in water supply and drainage system of ironmaking blast furnace?

The expansion tank is not only used in the water supply and drainage system of ironmaking blast furnace, but also often used in the chilled water pipeline of air conditioning.

Its working principle is very simple, that is, to ensure that the pressure in the whole pipeline is kept at a certain value, and the pressure will not change greatly because of the long pipeline or lack of water.

Its structure consists of a pressure tank with a spring inside and a pump. Under the action of the spring, the inside of the tank keeps a certain pressure in the pipeline. When the pipeline is short of water or the pressure is unstable, quickly replenish the water in the tank and start the water pump to replenish water. When the pressure exceeds, water will be absorbed by the tank, thus stabilizing the pipeline pressure!