Stainless Steel Pipe Fittings

How to judge the flange was corroded

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Flange in the use of industrial structures, mainly to improve the role of the connection, and to keep the seal of the pipeline no leakage, but many of the national standard flange after the use of a period of time will appear their own corrosion aging, which lost the effect of sealing, It is very necessary to do a regular anti-corrosion test on the flange. Here we share the process of measuring the corrosion of the flange.

First of all must be sure that the flange to its regular maintenance and testing, after corrosion, usually the performance of the flange wall thinning, the emergence of local pits and pits. For the American standard flange internal corrosion causes and methods need to follow a certain way and principle, can now use at home and abroad more extensive flange corrosion detection method is the leakage flux method and ultrasonic detection method.

Ultrasonic ultrasonic wave detection method is the use of ultrasonic pulse reflection principle to measure the thickness of the wall after corrosion. The basic principle of the magnetic flux leakage method is based on the high permeability of the ferromagnetic material, the permeability of the flange corrosion defects is much smaller than the permeability of the flange, Magnetic field lines are mostly distributed through the steel pipe, when the magnetic field lines are evenly distributed; when the flange inside the defect, the magnetic field lines are bent, and a part of the magnetic field leakage out of the steel pipe surface. Detection of the magnetized flange surface to escape the leakage flux, you can determine whether the defect exists.

In addition, the probe will detect the ultrasonic pulse to the inner wall of the flange, the probe will first receive the reflection pulse from the inner surface of the pipe wall, and then the ultrasonic probe will receive the reflection pulse from the outer surface of the pipe wall. The pulse and the inner surface reflect the pulse The distance between the rows reflects the thickness of the pipe wall. Elbow in the actual test need to follow the actual situation and instructions, according to the ultrasonic method to detect a good way to test.

The use of ultrasonic testing also applies to other metal structural parts thickness measurement and metal properties.

China Flange Manufacturer Yaang Pipe Fitting Division Exports Flanges or flow control of oil, gas, water, steam, acid liquid, etc.

Source: China Flange Manufacturer – Yaang Pipe Industry Co., Limited (

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