METHOD OF DIAGNOSTICS OF CONDITION OF MAIN PIPE-LINES Russian patent published in 2000 - IPC

FIELD: nondestructive inspection and diagnostics of condition of main pipe-lines in process of their usage. SUBSTANCE: optimization of inspection mode of pipe-lines and increased authenticity of detection of all types of flaws are achieved thanks to movement of tool-flaw detector inside pipe-line. Ultrasonic inspection of wall of pipe- line with transmission of sounding pulses of ultrasonic vibrations into wall of pipe-line via transported product is conducted. Ultrasonic waves are excited in wall of pipe-line, signals reflected from inhomogeneities of material of wall of pipe-line are used as parameters by which character, sizes and location of flaws in wall of pipe-line are evaluated. Ultrasonic Lamb waves are excited in wall of pipe-line and level of radioactive radiation of natural radionuclides accumulated on wall of pipe-line and/or in ground bordering on external surface of pipe-line and contained in transported products and products of their decay is additionally recorded simultaneously with ultrasonic inspection. Sections of surface of pipe-line with increased level of radiation are isolated and are subjected to additional ultrasonic inspection with sending of additional sounding pulses of ultrasonic vibrations with another frequency different from main sounding pulses and ultrasonic Lamb waves of another mode are excited in wall of pipe-line. EFFECT: increased authenticity of detection of all types of flaws in walls of pipe-lines. 9 cl