the current inspection technology named LRUT is widely used by oil and Gas company. Basically, LRUT sometime called as Guided waves are mechanical stress waves that propagate contained within the structural boundaries of pipes or plates with wavelengths that are comparable to the thickness dimensions of the pipe or plate.
LRUT / Guided waves are used by inspection company in rapid testing or Screening tools to detect, locate and classify corrosion defects. Large sections of pipeline / piping can be quickly screened with 100 % coverage to determine precise locations of metal damage.
After conducted the screening, more detailed inspections can then be focused on the locations that are critical, thus saving money and time. These local inspections can be done using guided wave Scanning equipment or with another complementary non-destructive testing method like UT flaw detector. This approach of screening and scanning provides a cost‑effective means of ensuring that representative measurements are made over considerable lengths of pipeline.
LRUT / Guided for the in-service surveying of metal loss in pipelines and piping was developed in the 1990’s through a UK Technology collaboration of Imperial College and the Research Institute TWI which culminated in the release of the first Guided Wave testing product Teletest® in 1998. The development and improvement of LRUT has been rapid over the first 20 years since the first product has been commercially available. The equipment can now generate and fully utilize any of the three main Guided Wave types (longitudinal, torsional and flexural). There has also been significant developments in utilizing phased-array technology making it possible to focus the ultrasound and analyze the circumferential responses of potential defects. In addition, the boundaries for inspection has increased such that the inflatable collars, modules and transducers are capable of inspecting pipe and pipeline sizes up to 78” and increased temperature capability of 240°C.