Steel pipe  products are widely used in tap water engineering, the petrochemical industry, the chemical industry, the power industry, agricultural irrigation, and urban construction, but after a long time of use, steel pipe will certainly have rust, the occurrence of long rust, the main use of wire brush and other tools to polish the steel surface, can remove loose or warped oxide skin, rust, welding slag and so on. Manual tools can reach Sa2 level, power tools can reach Sa3 level, if the steel surface is firmly attached to the oxide sheet, the tool rust removal effect is not ideal, and can not meet the construction requirements.

How to remove the rust from steel pipe in the factory? 

Now we will introduce the process of removing the rust from steel pipe.

(1) Spray derusting is driven by a high-power motor jet blade with high-speed rotation, so that abrasive steel sand, steel balls, iron wire segments, minerals and other abrades under the action of centrifugal force spray treatment on the surface of the steel pipe, not only can all clean rust, oxide, and dirt, and the steel pipe under the action of abrasive fierce impact and friction force, but also can achieve the required uniform roughness.

(2) Too small a roughness will cause the adhesion and strength of the layer to decrease. For serious internal pitting, it is not only necessary to rely on the impact of large abrasive particles, but also need to rely on small particles to polish off the corrosion products to achieve the cleaning effect. At the same time, a reasonable ratio design can not only slow the wear of abrasive on the pipeline and nozzle but also improve the utilization rate of abrasive. Generally, the particle size of steel pellets is 0.8~1.3mm, and the particle size of steel sand is 0.4~1.0mm, of which 0.5~1.0mm is the main component.

(3) After rust removal, it can not only expand the physical adsorption of the pipe surface but also enhance the mechanical adhesion between the layer and the pipe surface. Therefore, jet rust removal is the ideal way of pipe rust removal. Generally speaking, shot peening is mainly used for pipe inner surface treatment, and shot peening is mainly used for pipe outer surface treatment.

(4) In order to obtain better uniform cleanliness and roughness distribution, the design of abrasive particle size and proportion is very important. Too large roughness is easy to make the layer thin at the peak of the anchor grain. At the same time, because the anchor grain is too deep, bubbles are easy to form in the middle layer of the process, which seriously affects the performance of the steel tube coating.

It should be noted that in practice, the ideal ratio of steel sand to steel pellets in abrasives is difficult to achieve because hard and fragile steel sand has a higher breakage rate than steel pellets. To this end, in the operation should be constantly sampling detection of mixed abrasives, according to the particle size distribution, to the rust remover into the new abrasives, and the new abrasives mixed with people, the number of steel sand to account for the main. The derusting speed of steel pipe depends on the type of abrasive and the displacement of abrasive, that is, the total kinetic energy E of abrasive applied to the straight seam steel pipe and the kinetic energy E1 of single particle abrasive within a unit of time. When the equipment is fixed, m is a constant and y is a constant, so E is also a constant. However, due to the abrasive breakage, m1 changes. Therefore, abrasives with lower loss rates should be generally selected, which is conducive to improving the cleaning speed and the life of long blades.

For the construction process of epoxy, ethylene, and phenolic coatings commonly used in steel pipes, the surface of steel pipes is generally required to reach nearly white grade (Sa2.5). It has been proved that almost all the oxide skin, rust, and other dirt can be removed by using this derusting grade, and the anchor grain can reach 40~100μm, which fully meets the adhesion requirement between the layer and the steel pipe. The process of derusting by spraying (throwing) can achieve the near white grade (Sa2.5) with low operating cost and stable technical conditions. In order to achieve the ideal rust removal effect, the abrasive should be selected according to the hardness of the steel pipe surface, the original degree of rust, the required surface roughness, coating type and so on. For the single-layer epoxy, two or three layers of polyethylene coating, the abrasive mixture of steel sand and steel pellets is easier to achieve the ideal rust removal effect. Steel shot has the effect of steel surface, and steel sand has the effect of etching the steel surface. The abrasive mixture of steel sand and steel pellets (usually the hardness of steel pellets is 40~50HRC, and the hardness of steel sand is 50~60HRC can be used for various steel surfaces. Even if it is used on the surface of grade C and grade D corroded steel, the rust removal effect is very good.

Cangzhou Shenlong Pipe mainly produces seamless steel pipe, straight seam steel pipe, and spiral steel pipe, but also can process galvanized, anti-corrosion coating, has more than 20 years of production history, reliable quality, is a qualified supplier of BP oil, Petro China.