NONDESTRUCTIVE TESTING IN OIL REFINING AND THE CHEMICAL INDUSTRY

摘要

It is necessary to provide reliable operation of petrochemical plant in Russia although it is ageing and there are strictly constrained financial and material resources (renewal factor for capital investment less than 2%, equipment wear 70%), which means that increasing attention is needed to diagnostic and preventative service. The best effect in industry comes from nondestructive test technologies that do not involve penetrating a system and give rapid scans of extensive areas, in order that one can use sample and local standard monitoring methods. The best technologies are ones that require no or few preparative procedures such as surface preparation, removal of insulation, and the like, and for which it is not necessary to shut down the plant for the purpose. Various forms of damage are characteristic of petrochemical plant: corrosion, wear, deformation, swelling, and fractures. Traditional nondestructive test methods are still widely used mainly for identifying corrosion and erosion, and ultrasonic thickness gauging and gamma-ray flaw detection are used to estimate the residual thicknesses of pipe and vessel walls, while visual methods are used mainly to evaluate surface states. Capillary detection methods are used with components made of titanium and corrosion-resistant steels in order to detect corrosion formed by chlorides, while magnetic powder testing is used to identify defects in vessels and welded pipeline joints. Heat-exchange tubes are often checked with the equipment withdrawn from use by the application of internal or remote eddy-current sensing, and also by examining the magnetic leakage flux in relation to tube configuration. Preventive service includes methods providing safe continuous operation from objective instrumental data on the actual state. In the chemical, petrochemical, and oil refining industries, the main sources of these data are provided by acoustic-emission monitoring on vessels, plant, pipelines, and so on together with vibrational monitoring on dynamic equipment (pumps and compressors) and thermographic tests for the objective monitoring of a wide range of equipment, including electrical power distribution systems.