Common problems in magnetic flux leakage testing of sucker rods:
1) The cleaning of the sucker rod is not clean, and the maintenance of the probe is difficult, which affects the detection accuracy.
2) The sucker rod surface with small corrosion point has low sensitivity and error in circumferential sensitivity.
3) The sucker rod with coupling causes runout interference when transporting, which affects the detection when the detection accuracy is particularly high and is prone to a false alarm.
In view of the above three problems, we will discuss them one by one.
1) The sucker rod is not clean:
It is usually difficult to clean sucker rods, especially in winter. Oil contamination is often left in the probe during sucker rod inspection, which leads to a decrease of detection accuracy. To solve this problem, our company has successfully developed an "external open" high sensitivity magnetic flux leakage detection probe for sucker rods by adjusting the magnetization structure and magnetization mode. Because of the external and open design of the probe, it brings great convenience to the cleaning and maintenance of the probe and can be cleaned regularly, thus ensuring the detection accuracy.
2) The sucker rod surface with small corrosion point has low sensitivity and the circumferential sensitivity has errors.
The main defects of sucker rod are surface corrosion point and fatigue crack, which easily cause sucker rod fracture. At the same time, the distribution of corrosion points in any position on the surface, if the circumferential sensitivity error is large, it is easy to cause missed detection, false detection. By improving the structure of the sucker rod detection probe and optimizing the coil parameters inside the probe, the detection ability and sensitivity have been greatly improved, which can effectively detect the surface corrosion points, loose material and fatigue cracks of the sucker rod. At the same time, the circumferential sensitivity of the probe is very uniform, and the detection stability and reliability reach a high level.
3) Pumping rod with coupling causes runout interference during transportation.
Because of the coupling in sucker rod flaw detection, it causes runout interference when conveying, and affects the detection when the detection accuracy is particularly high, which is prone to a false alarm. The transmission rollers on the main machine of sucker rod magnetic flux leakage testing equipment are all controlled by the cylinder. Under the control of the computer, the coupling of sucker rod can be automatically avoided, thus effectively avoiding the interference signal caused by the running of the coupling through the roller. At the same time, the sucker rod probe also adopts floating tracking technology, which further eliminates the runout interference and achieves very good results.