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How to Maintain Automatic Spray Gun Nozzles?

How to Maintain Automatic Spray Gun Nozzles?

To ensure that the pre-treatment system can run at maximum efficiency and maintain surface treatment quality, the key component of the system, the automatic spray gun nozzle, must be maintained regularly. Delaying the maintenance of the nozzle will distort the spray status, causing wastage of pre-treatment material and decreased quality of surface treatment.

Learning to identify, solve and avoid nozzle failure can help businesses save cost of pre-treatment material, prevent energy wastage, ensure product surface treatment quality and reduce equipment damage. Below are some maintenance tips for the automatic spray gun.

Causes of nozzle failure of the auto spray gun


When high-speed liquid passes through the metal surface of the nozzle hole, it causes erosion of the nozzle hole, leading to a decrease in nozzle pressure and irregularity in spray status. The likelihood of nozzle corrosion depends on the hardness of the liquid, the type of chemical material used for spraying pressure and any impurities in the liquid that can cause severe nozzle erosion.

Accidental damage

Improper use and timely maintenance are the main reasons for accidental nozzle damage of the automatic spray gun. Although the nozzle mouth is usually designed as a concave shape, the offset structure of the fan-shaped nozzle is easily damaged.


When chemical materials are used to wash the product, they also cause corrosion of the nozzle material.


The accumulation of chemical materials and impurities in the nozzle inside or outside edge can cause nozzle blockage, which affects the spray shape of the nozzle and thus affects the spraying pressure.


Long-term operation of the nozzle under high or abnormal temperature causes damage to the nozzle due to material softening.

Recognition of auto spray gun nozzle problems

When the spray pump runs at its rated capacity, the spray pressure of the nozzle will decrease as the nozzle aperture increases. Even if the actual flow rate of the damaged nozzle exceeds its rated flow rate by 30%, it is difficult to recognize the change in its atomization status with the naked eye.

The best way to identify nozzle problems is to observe the pressure changes in the spray pipe. When comparing different nozzles of the same pre-treatment system, the position and accuracy of the pressure gauge are crucial. The pressure gauge should be placed at the front end of the spray pipe. When determining the pressure changes in the spray pipe, the spray pressure of the good nozzle should be used as a reference, and the difference between the actual pressure and the reference pressure can be used to determine if there is a problem with the nozzle.

Troubleshooting of auto spray gun nozzle problems

Since it is difficult to directly detect nozzle problems with the naked eye, the selection of nozzles must be given priority. After selecting the appropriate nozzle, a complete maintenance and replacement plan should be in place.

Regularly check the nozzle

This includes regular cleaning of the nozzle and regular inspection of the nozzle's appearance for damage. Generally, the nozzles for the first few processes (such as pre-degreasing and degreasing) of the pre-treatment production line should be checked and cleaned every shift, and the inspection and cleaning frequency of the nozzles for subsequent processes can be appropriately extended.

Regularly replace the nozzle

The frequency of nozzle replacement for the automatic spray gun depends on the environment in which it operates, the composition of the spray liquid and the material of the nozzle. If the temperature is high and there are impurities in the spray liquid, the nozzle needs to be replaced more frequently.

The nozzle has a significant impact on the operation of the entire pre-treatment system. Frequent nozzle problems will result in increased material costs, increased energy consumption and decreased quality of the product. Therefore, it is crucial to prevent, detect and solve nozzle problems in a timely manner.

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