FIELD: diagnostics of pipes laid and run under extreme conditions with limited possibilities of access. SUBSTANCE: pulse coaxial field is excited in pipe from side of internal surface via liquid transported product. Pairs of pulses passed through material of pipe and re-emitted continuously and single pulses re-emitted locally are received, their time of arrival and time intervals between pulses in pairs are measured and used to evaluate presence of defects and parameters of pipe. Duration and frequencies of vibration of each pulse in pair are measured in addition, their values and relations determine presence, dimensions, character and risk of anomalous zone, presence and value of bending stress in pipe. Gear for ultrasonic diagnostics has radiator exciting cophasal ultrasonic field of coaxial wave uniform by intensity, two separate units of receiving converters, one being made in the form of cylindrical shell, another has shape of cone. EFFECT: generation of new information making it feasible to enhance accuracy and authenticity of evaluation of service life of pipes. 13 cl, 7 dwg
