The ultrasound inspection method has gained a wide recognition due to its reliability and comparative simplicity of application. The method is based on the ability of waves to be reflected from obstacles that are larger than half-wavelength.
This technology is used to determine the ageing degree of pipes in main pipelines, and of other assemblies and mechanisms. US inspection equipment is most widely deployed in oil, chemical, aviation and machinery building industries, as well as in public utilities.
NDT instruments are used both in the laboratory and in the field. The technology has proven to be excellent for diagnostics of boilers and other units operating in high temperatures and pressures, and in corrosive media. It even allows for inspecting items of complex geometry.
Among the weaknesses of US inspection, first of all, is the limited character of information on a welded joint fault. Besides that, strong wave dissipation and attenuation creates difficulties during inspection of metals with coarse-grained structure. And finally, a weld should be prepared for the diagnostics beforehand.
Nevertheless, the advantages of the US inspection method are far more numerous than its shortcomings:
· All-purpose application. The technology is suitable for cast iron, copper, austenite and alloy steels. US inspection instruments are excellent in detecting pores, lacks of fusion, cracks, stratification, discontinuities, wormholes, corrosion, slacks, alien inclusions, etc. The diagnostics can be performed on flat, longitudinal, girth, tee-butt seams, splices, etc.
· Fast inspection, precision and accuracy of results.
· Safe for personnel.
· Outage-free operation of the inspected facility or its parts.
· Integrity of the tested structure and material.