Inspection method of straight seam welded pipe

Straight seam welded pipe is a kind of pipe which is made of hot rolled or cold rolled steel plate or steel coil and there is a straight line on the welding place so the term of the steel pipe comes from that straight line. Nowadays, the application rate of the steel pipe is frequently especially for the pre galvanized steel pipe and the application range not only includes the construction industry whose raw material is steel pipe but also chemical industry. In order to understand this kind of steel pipe, we should master the inspection methods of it. Do you know how to inspect?

The first one is a kind of physical method that is magnetic inspection which can find the flaw of the steel pipe surface and we can get a quantitative analysis about these defects. However, for some welding line including property and depth, we can only make a judgment by our experiences formed by many years of working experience in construction industry. What is the working principle of the magnetic inspection? Actually, it can find faults from the magnetic flux leakage from magnetic filed when magnetization happens. According to the measurement method of the magnetic flux leakage, the inspection method for welded steel pipe can be divided into magnetic powder and magnetic recording and so on. An examiner wants to know whether the steel pipe he purchases is straight seam welded pipe or not, he can adopt this method.

Another method is permeation inspection. It is a kind of method by using some physical properties such as the permeability of the liquid to find the defects. Understanding the type or defects of the round steel pipe can help us choose the desirable products speeding up the course of your project.

The last method is ultrasonic flaw detection. Ultrasonic wave can be transmitted on the metal and other even medium. This kind of method can be used for internal defect inspection because reflection arises on the different medium interface. Ultrasound can test any welding materials like square steel pipe and it can test defect position quickly especially for the flaw of the pipe shape and size. All these methods can test welded steel pipe and after testing, you can purchase the suitable products whose price will be a little higher while the most important factor is the pipe quality. Now do you know how to inspect straight seam welded pipe?