The working principle of the pump head: press the pressure handle downward manually, the volume in the spring cavity decreases, the pressure increases, the liquid enters the nozzle cavity through the hole of the valve core, and then sprays out the liquid through the nozzle. At this time, release the pressure handle, the volume in the spring cavity increases, forming a negative pressure. The ball opens under the negative pressure, and the liquid in the bottle enters the spring cavity. At this time, there is a certain amount of liquid in the valve body, When the handle is pressed again, the liquid stored in the valve body will rush upward and spray outward through the nozzle;

The key to a good pump head is to pay special attention to the following points:
1. The sealing of the glass ball or steel ball under the spring is very important, which relates to the strength of the liquid in the spring chamber to flush upward. If there is leakage here, when the pressure handle is pressed, some of the liquid will leak into the bottle, which will affect the effect of liquid spraying;
2. It is the sealing ring at the upper end of the valve body. If there is leakage, the bottom of the upward pumping force of the liquid will be reduced when the pressure handle is released, resulting in a small amount of liquid stored in the valve body, which will also affect the spray effect;
3. The fitting between the pressure handle and the valve core. If the fitting here is loose and there is leakage, there will be some resistance when the liquid rushes up to the nozzle, and the liquid will flow back. If there is leakage here, the spray effect will also be affected;
4. The design of nozzle and the quality of nozzle design are directly related to the effect of spray. See the next page for details on nozzle design;
Therefore, the function of the pump head is generally tested at these four positions, and other appearance and matching problems are detected according to the routine