Longitudinally welded steel pipe maintenance collection

Longitudinally welded steel pipe maintenance collection

The longitudinal welded pipe has a simple production process, high production efficiency, low cost, and rapid development. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. A narrower blank can be used to produce welded pipes with larger pipe diameters, and a billet with the same width can also be used to produce welded pipes with different pipe diameters. But compared with the straight seam pipe of the same length, the weld length is increased by 30-100%, and the production speed is lower. Therefore, most of the smaller diameter welded pipes use straight seam welding, and the large diameter welded pipes mostly use spiral welding.

Longitudinally welded steel pipe derusting and maintenance method:

Longitudinally welded steel pipe equipment plays an important role in life and work. Generally, the surface of Longitudinally welded steel pipe fittings is required to reach nearly a white level (Sa2.5). The construction technology of epoxy, vinyl, phenolic, and other anticorrosive coatings is commonly used for Longitudinally welded steel pipe fittings. Almost all oxide scales, rust, and other contaminants can be removed by using this rust removal level. The depth of the anchor pattern reaches 40~100μm, which fully meets the requirements of adhesion between the anti-corrosion layer and the steel pipe. The spray (throwing) rust removal process can be more Low operating cost and stable and reliable technical conditions reaching near-white level (Sa2.5). When the rust of the Longitudinally welded steel pipe occurs, it shall be treated by the rust removal method and method to ensure the and performance of the Longitudinally welded steel pipe.

Spraying (throwing) abrasives for longitudinal welded steel pipes:

To achieve the ideal rust removal effect, the abrasive should be selected according to the surface hardness of the Longitudinally welded steel pipe equipment, the original rust level, the required surface roughness, and the type of coating. For single-layer epoxy, two-layer, or three-layer polyethylene coating, Layer, the mixed abrasive of steel grit and steel shot is easy to achieve the ideal rust removal effect. The reason for choosing steel shot is that the steel shot has the effect of strengthening the steel surface, while the steel grit has the effect of etching the steel surface. The rust removal effect is also very good.

Inspection method of longitudinal welded steel pipe:

At present, it is widely used to use magnetic powder to detect Longitudinally welded steel pipes. Generally, a magnetic inspection can only detect defects on the surface of welded pipes, and many problems can not be reflected well, and they are usually judged based on experience. So the reason is to use waves and rays together. Such inspection can sensitively detect the defects of welded pipes, but there are also defects in such inspection methods, which cannot determine the material, shape, size, etc. of welded pipes. The current inspection methods are all physical inspection methods, which can not only reduce the damage to the material but also accurately reflect the problem of material defects.