The automatic control valve of booster pump is divided into three parts: main valve body, diaphragm control room and bypass pipe. With the diaphragm as the boundary, the upper cavity above the diaphragm is connected with the drainage pipe, and the lower cavity below the diaphragm is connected with the valve inlet pipe. The small valve plate is fixed on the valve rod, and the large valve plate slides up and down on the valve rod. When the motor is started, the pressure at the valve inlet increases gradually, and the pressure water:

1）產(chǎn)生推動(dòng)大閥板向上的力，此時(shí)閥門(mén)不能立即打開(kāi)（因為膜片控制上腔有背壓）。

1) When the force pushing the large valve plate upward is generated, the valve cannot be opened immediately (because there is back pressure in the upper chamber of diaphragm control).

2）壓力通過(guò)旁通管進(jìn)入膜片控制腔下腔。隨著(zhù)下腔進(jìn)水量增加，當下腔的壓力大于上腔的壓力時(shí)，下腔壓力水推動(dòng)膜片往上移動(dòng)，這時(shí)小閥板沒(méi)有對大閥板施加壓力。

2) The pressure enters the lower chamber of the diaphragm control chamber through the bypass pipe. With the increase of water inflow into the lower chamber, when the pressure in the lower chamber is greater than that in the upper chamber, the pressure water in the lower chamber pushes the diaphragm upward. At this time, the small valve plate does not exert pressure on the large valve plate.

3）大閥板有一種力推動(dòng)其往上移動(dòng)，在這兩個(gè)力的作用下，閥門(mén)逐漸打開(kāi)，從而達到啟泵時(shí)輕載、閉閘、緩開(kāi)的目的。當突然停電或事故停泵或正常停泵時(shí)，閥門(mén)進(jìn)水口處壓力水流速降低，大閥板也隨之下降，當其流速為零時(shí)（即進(jìn)水口處流速為零時(shí)），大閥板由于自身重力而迅速關(guān)閉（時(shí)間3s～5s），可防止大部分水倒流，此時(shí)閥門(mén)前后形成一種水壓差，壓力水一方面通過(guò)小閥板底部的三條泄壓槽進(jìn)行泄壓。

3) The large valve plate has a force to push it upward. Under the action of these two forces, the valve will gradually open, so as to achieve the purpose of light load, closing and slow opening when starting the pump. In case of sudden power failure, accidental pump shutdown or normal pump shutdown, the pressure water flow velocity at the valve inlet decreases, and the large valve plate also decreases. When the flow velocity is zero (i.e. when the flow velocity at the water inlet is zero), the large valve plate closes rapidly due to its own gravity (for 3S ~ 5S), which can prevent most of the water from flowing back. At this time, a water pressure difference is formed in front of and behind the valve, On the one hand, the pressure water is relieved through three pressure relief grooves at the bottom of the small valve plate.

4）壓力水從旁通管進(jìn)入膜片控制室上腔（此過(guò)程為吸壓腔，能有效吸收一部分水能量），當上腔壓力水大于下腔時(shí)，壓力水推動(dòng)膜片往下移動(dòng)，當下腔壓力水全部被擠出來(lái)時(shí)，小閥板緩緩下降，恢復到待機狀態(tài)，此過(guò)程中緩閉時(shí)間可調節（3s～150s），屆時(shí)閥板已全部關(guān)閉，滴水不漏。正因為其停機時(shí)具有速閉、線(xiàn)性泄壓、吸壓腔及緩閉等四種水錘功能，故停機時(shí)無(wú)一點(diǎn)響聲產(chǎn)生，效果很好。

4) The pressure water enters the upper chamber of the diaphragm control room from the bypass pipe (this process is a pressure absorption chamber, which can effectively absorb part of the water energy). When the pressure water in the upper chamber is greater than that in the lower chamber, the pressure water pushes the diaphragm down. When all the pressure water in the lower chamber is squeezed out, the small valve plate slowly drops and returns to the standby state. The slow closing time in this process can be adjusted (3S ~ 150s), At that time, all valve plates have been closed without leakage. Because it has four water hammer elimination functions such as quick closing, linear pressure relief, pressure suction chamber and slow closing, there is no sound during shutdown, and the effect is very good.