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The Details of the Welded Steel Pipe
Date:2015-08-27      Views:1231Time      Label:welded steel pipe

Straight seam welded pipe quality inspection method has a lot of kinds, including physical method which is the most commonly used inspection method, physical test some physical phenomena is used for measurement or test methods. Material or internal defects of  inspection, are generally adopt the method of nondestructive flaw detection. Such as NDT magnetic testing, ultrasonic testing, penetration testing and so on. Magnetic testing can only be found magnetic straight seam welded pipe surface and near surface defects. And can only do quantitative analysis of defects, for the nature of the defect and depth also can only be estimated according to the experience. Magnetic inspection is ferromagnetic magnetization of the magnetic fields produced by welded steel pipe leakage to find defects according to different methods of magnetic flux leakage. The magnetic particles can be divided into method, induction method and magnetic recording, of which the most widely used method of magnetic powder.

Radiographic examination is to use the rays can penetrate and attenuation in the material properties to find a flaw detection method of the welded steel pipe. According to the detection of radiation is different, can be divided into X ray flaw detection and gamma ray flaw detection and high-energy X-ray detector. Ray inspection is mainly used for straight seam welded pipe inside weld crack, lack of penetration, porosity, slag inclusion and other defects. Ultrasound in metal and other homogeneous medium propagation, due to the different medium interface of welded steel pipe will produce reflection, thus can be used in the inspection of internal defects. Ultrasound can test any welding materials, any part of the defects, and is more sensitive to find defect position, but the nature of defects, shape and size are difficult to determine. So straight seam welded pipe ultrasonic testing is often used with X-ray inspection.

General welded steel pipe is used for transporting oil, heating steam and other fluid with low pressure. The making of ordinary carbon steel wire, an industrial and civil construction, the installation machinery and equipment, the steel pipe of electrical installation and so on are used for protecting the wire. The welding line of the straight seam welded steel pipe and the steel tube parallel the longitudinal welded steel pipe. It usually contains metric welded pipe, welded thin-wall tube, and transformer cooling pipe and so on.

The spiral seam submerged arc welding pipe equipped on the pressurized fluid conveying called hot rolled steel coil tube billet. It is usually spiral shape to be used for pressurized fluid conveying by the spiral seam steel pipe with double-sided submerged arc welding methods. The confined ability and good welding performance of the welded steel pipe can be tested by strict scientific inspection to ensure the reliable and safe use. The diameter of steel pipe is big with high transmission efficiency, which can save laying pipelines. Mainly used for conveying oil, natural gas pipeline.

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