At present, there are many models and styles of hand-operated pumps on the market, and detailed descriptions are often attached to each type of pump, but in terms of structural design and technology, they can be roughly classified into the following six categories.
Category 1 General operating pumps. When the pump is pressed by hand, the desired product can be sprayed out under the action of force. When pressurizing this kind of pump, the speed and force of pressurization have an effect on the working state of the pump, such as strong and rapid pressurization, the pump can achieve the best spray effect (such as finer droplets, larger fog cones, or longer range, etc.).
The second type of ordinary two-stage pump. This pump is equipped with two seals, a spherical ball seal, and a secondary plastic seal. The pre-pressing action of the second stage can make the pre-pressed material spray the liquid medicine through the nozzle.
The third category is a modified two-stage pump. The operating principle of this pump is similar to the two-stage pump system with a spherical seal and plastic seal described above. It does not use ball and ball seals in the structure; it uses the principle of shaft ring pressure sealing, and its performance is superior to the former.
Category 4 This type of pump works on the same principle as the third category but has no separate air supply channel, is completely sealed, isolated from the atmosphere, and must be inflated. This type of pump is essentially a quantitative pump.
The fifth type of pump is also similar to the two-stage pump. It is usually in a non-inflated pressurized condition. Once the tank is filled with air, it will seal itself. When the piston is actuated, the passive piston of the pump compresses the spring making the pump an up-reverse valve. The contents in the container can only be discharged to the predetermined volume when the active piston is pressed down to the set distance, and will not be discharged when the piston does not reach the set distance, thus ensuring the accuracy of the discharge volume. This kind of pump also belongs to the quantitative pump.
Category 6 This is a new type of pump system improved on Category 5 pumps. When this pump is in operation, the container is only sealed when the valve is depressed. The content of the quantitative chamber of the pump is sealed by the sleeve and the wall of the pump body. When the nozzle is pressed, the contents of the quantitative chamber are discharged, which can prevent the liquid in the container from contacting the metal parts and ensure that the liquid will not come into contact with the metal parts. Contamination affects quality and performance.
