Figure 1-4 shows the schematic diagram of manual control of liquid level. The liquid continuously flows into the storage tank l through the inlet valve 2, and at the same time, it continuously flows out through the outlet valve 4. It can be seen that the liquid level in the tank will fluctuate with the inflow or outflow. When the fluctuation is serious, the liquid in the tank may overflow or be evacuated. To solve this problem and keep the liquid level within a certain range, the simplest way is to install a glass tube level gauge 3. With the upper and lower limit scale lines of the liquid level gauge as the standard, when the liquid level rises close to the upper limit scale, the opening of the outlet valve can be increased or the opening of the inlet valve can be decreased; When the liquid level drops close to the lower limit scale, the outlet valve can be turned down or the inlet valve can be turned up, so as to avoid the overflow of the storage tank due to the high liquid level or the evacuation due to the drop of the liquid level, and keep the liquid level within a certain range. This process is directly controlled by people, so it is called manual control.

Although many people think that if they can run on the production line, it is an alternative experience for them, but if there is life danger on the production line, many people are certainly unwilling to do so. In fact, how can we make production more smoothly, But our personal safety can be guaranteed. In such a situation, if we can operate conveniently, use certain equipment, and use certain decorations, it is certainly the best for us, because we see that pneumatic ball valves are really easy to operate, but anyone who can know which side to turn, This kind of device can be operated. From such a thing, we can also see that it is really very convenient, because as long as we turn 90 degrees, everything is just as we want.