Preparation work: prepare relevant materials and tools, the equipment used is ready, and the staff is ready; chemical degreasing soaking method is used in the tank, the oil removal tank is made of steel plate, and the inner wall is covered with PVC or polyethylene. Chemical degreasing with 12-15% nitric acid, temperature 40℃～60℃, time 2～4 hours. When the 20G seamless pipe is soaked in the tank, attention should be paid to the placement position to prevent air from remaining in the pipe.
During the soaking process, the seamless tube should be moved up and down or turned over, and the inner cavity solution should be replaced continuously to improve the effect. If necessary, remove the seamless tube, rinse with water, and soak. Chemical degreasing until the surface is completely wetted by water; Rinse with hot water, take out the degreased 20G seamless pipe from the degreasing tank, and put it into a hot water tank at about 40-60℃ for 5-20 minutes.
The hot water tank is made of steel plate, the inner wall is covered with PVC or polyethylene, and the chloride ion content in the water is less than 25ppm; the seamless pipe washed with hot water is washed with pressure water; Use the tank bubble method in the pool, and operate the passivation solution formula and soaking time according to the relevant specifications.When immersed in the tank, pay attention to the placement position to prevent air from remaining in the tube. During the soaking process, the seamless tube should be moved up and down or turned over, and the inner cavity solution should be replaced continuously to improve the effect.
Pipes are dried and passivated. The seamless pipe should be dried with clean compressed air or nitrogen, and there must be enough time for it to enter and be naturally passivated in the air;
Quality inspection, after passivation of the seamless pipe, self-inspection and mutual inspection are carried out, and the inspection is submitted to the quality inspector as required;
Packaging maintenance, such as the outer surface of the seamless pipe needs to be painted, according to the painting requirements.
After inspection, the seamless tube is sealed with a plastic plug, wrapped with a three-proof cloth for maintenance, and marked.