services : electromagnetic inspection

After thorough cleaning, visual inspection, and gauging, sucker rods are subjected to electromagnetic inspection consisting of a computerized flux leakage system for detection of surface discontinuities such as corrosion pits, mechanical damage, and manufacturing flaws, and an eddy current device for detection of stress induced localized hardness variations.

Our flux leakage system performs nondestructive examination of surface and near-surface discontinuities in sucker rods. The key to the successful application of this method is that within a magnetized rod, the magnetic flux field will be distorted in the presence of a discontinuity and the resulting indication will be detected. Magnetic fields are usually represented by magnetic flux lines. Magnetic flux lines tend to travel the path of least magnetic resistance. This causes the field to exit and reenter the rod at the discontinuity site. This condition is called flux leakage. Special detectors sense the density and geometry of the flux leakage patterns and transfer electrical impulses to a sophisticated signal processing console. Signals are amplified and filtered and displayed by a computerized data acquisition program that provides a visual representation of the location and severity of the discontinuities.

All product is thoroughly cleaned prior to inspection to remove any foreign material that may hinder the inspection process.

Rods are propelled through the encircling coils at a constant measured line speed by a fully automated hydraulic drive system controlled by photo-electric cells.

The desired magnetic fields are induced utilizing calibrated encircling coils. Magnetic field strength and orientation is confirmed with a calibrated magnetometer. System sensitivity, linearity, and repeatability is confirmed at regular intervals using actual production representative reference rods with artificial discontinuities. System parameters are adjusted to provide maximum signal-to-noise ratio and to achieve optimum reference signal amplitude.

Flaw detection trace channels are displayed on a liquid crystal display flat panel monitor. All relevant indications are investigated and evaluated with calibrated measuring instruments prior to product classification. The electromagnetic signature of each and every rod inspected is stored on CD with its own unique file name and can be printed out or e-mailed, as can digital images of defects and imperfections corresponding to the flaw channel indications and final results data.

Typical imperfections detected by electromagnetic inspection are: fatigue cracks, corrosion pits, mechanical damage, manufacturing flaws, and hardness variations.