The purpose of cleaning the bright and precise seamless tube is to rinse off any residual acid and other impurities on the surface of the tube, in order to achieve a good passivation effect.

For the cold water cleaning tank of the bright and precise seamless tube, the flow should be kept full and high-pressure water should be continuously sprayed. The water pressure should be kept above 0.5MPa. Under these conditions, the mass concentration of acid in the cold water should not exceed 0.1g/L, otherwise the bright and precise seamless tube is prone to rust after acid washing. The quality concentration of acid in cold water should be checked once a day and night.

The hot water temperature in the hot water tank should be above 95°C, and there should be no acid in the hot water to prevent rust on the bright and precise seamless tube. A pair of water squeezing rollers at the outlet of the hot water tank should be tightly pressed to squeeze out the maximum amount of water from the surface of the precise and bright tube.

In the continuous pickling line, the bright and precise seamless tube is coated with oil after acid washing to prevent rust during the storage period (around 10 days) before rolling. However, in the box-type pickling line, passivation with the bright and precise seamless tube can only be used for rust prevention.

Passivation is the process of forming a passivation film on the surface of the bright and precise seamless tube after acid washing, improving its ability to resist environmental corrosion, and generally ensuring that the bright and precise seamless tube does not rust again within 2-3 days.