在閉式循環(huán)系統(tǒng)戶式中央空調(diào)，把壓力罐裝在系統(tǒng)的回水處，用來吸收系統(tǒng)膨脹水，防止系統(tǒng)產(chǎn)生負壓，穩(wěn)定系統(tǒng)的壓力。

In centralized closed circuits air condition system, the expansion tank suited to absorb the increased water volume when the temperature in the heating system increases, make the pressure stable.