Hello Pipe Enthusiasts!
Welcome back to #BPIPipeInsights. Previously we covered “Key Terms in the Steel Pipe Inspection Process (Part 1)”, which addressed MPS, ITP, Visual & Dimensional Inspection through Hydrostatic Test. In this next part, we will discuss Key Terms in the Steel Pipe Inspection Process: Non-Destructive Testing (NDT).
NDT is crucial in the inspection process because it allows examination of a steel pipe’s internal and external condition without damaging the material’s structure or function. Here are some key terms for NDT methods applied at PT. Bakrie Pipe Industries:
Ultrasonic Testing on Plate Lamination (UT Plate)
Ultrasonic Testing (UT) on Plate Lamination is a non-destructive method for detecting internal defects such as lamination, inclusions, or porosity in steel plate. UT uses high-frequency sound waves that are abnormally reflected if discontinuities exist, indicating areas that did not bond perfectly due to non-homogeneous rolling.
This inspection is performed before the material is processed into steel pipe, ensuring it is free of structural defects that could compromise weld integrity and final product performance. UT is effective because it can be done from one side, delivers rapid results, and can detect defects throughout the plate’s thickness.
Ultrasonic Offline Test (UT Offline)
Ultrasonic Offline Test is an ultrasonic inspection performed after production is complete. It uses high-frequency sound waves to detect inconsistencies in the material, such as cracks, porosity, or delamination.
Typically applied to inspect longitudinal and circumferential welds, the ultrasonic probe is moved manually or semi-automatically, and results are recorded as waveforms or digital reports. This test verifies internal pipe quality without dismantling or damaging the material.
Ultrasonic Online Test (UT Online)
Ultrasonic Online Test is conducted in real time during production. Unlike the offline version, this test is automated and integrated directly into the production line, usually immediately after welding.
Sensors or probes are mounted stationary or follow the pipe’s movement to detect defects or disbonds. Its advantage is high efficiency, automatically alerting operators to any non-conformities. This supports an early-detection quality system.
Phased Array Ultrasonic Test (PAUT)
PAUT is an advanced ultrasonic method that uses multiple sensor elements to steer the sound beam in a controlled manner (phasing). The result is a two-dimensional image of the pipe interior, enabling the detection of more complex defects with high accuracy.
This method is often used to verify online test results or on pipes with critical specifications. PAUT’s strength lies in its ability to pinpoint the location, size, and orientation of defects more precisely than conventional UT.
Radiographic Test (RT / X-Ray)
Radiographic Test uses X-rays or gamma rays to examine weld integrity in pipes. This method exposes film or a digital detector to the weld zone and then analyzes it for indications such as porosity, incomplete fusion, or cracks.
RT/X-Ray produces a shadow image of defects, so interpretation relies heavily on operator expertise. At PT BPI, RT is used for specific weld joints and is often combined with other NDT methods for cross-validation.
Magnetic Particle Test (MT)
Magnetic Particle Testing on ferromagnetic pipes involves magnetizing the material and applying fine magnetic particles. These particles accumulate at the tips of surface cracks or discontinuities, forming a visible indication of defects.
Liquid Penetrant Test (PT)
Liquid Penetrant Testing uses a colored or fluorescent penetrant applied to the pipe surface. After a dwell time, excess penetrant is removed and a developer is applied, making any dye trapped in surface cracks appear clearly.
Eddy Current Test (ECT)
Eddy Current Testing uses an alternating-current coil placed near the pipe surface without contact. Changes in coil impedance caused by defects or material variations generate signals that rapidly identify surface-near flaws.
Further discussions will follow
Thus concludes Key Terms in the Steel Pipe Inspection Process (Part 2), covering Non-Destructive Testing methods Especially at Bakrie Pipe Industries. With techniques like Ultrasonic Testing, Magnetic Particle Testing, Liquid Penetrant Testing, Radiographic Testing, and Eddy Current Testing, we ensure a steel pipe’s internal structure is safe without causing damage.
Leave a comment if you’d like to share your NDT field experiences, and be sure to follow our next updates on #BPIPipeInsights!
