Apparatus for detecting substantially longitudinal flaws in the end area of a tubular member using magnetic excitation and a scanning sensor

摘要

An apparatus for detecting substantially longitudinal flaws in the end area of a tubular member is disclosed. The apparatus comprises magnetizing-detection units, means for moving-said units along a helical path about the surface of the end area of the tubular member, and means for centralizing and securing the apparatus on the end of the tubular member being inspected. Magnetic detection transducers on the magnetizing-detection units detect perturbations in the applied magnetic field in the area of any substantially longitudinal flaws. The magnetic detection transducers are mounted so as to remain remote from the surface of the tubular member during operation of the apparatus. The field is generated in the tubular member by said magnetizing-detection units. The magnetizing-detection units are pivotably mounted to allow for movement over both flat and tapered surfaces. The signals generated by the magnetic detection transducers are transmitted to an external indicating device through slip rings.