METHOD OF TESTING PIPES FOR DURABILITY Russian patent published in 2016 - IPC G01N3/32 

FIELD: pipes.

SUBSTANCE: invention relates to hydraulic pressure testing, in particular, to methods of cyclic tests of real samples of pipes with internal pressure and bending in order to obtain actual data on their strength and durability. Summary: real pipe specimen installation is performed with plugs welding to ends of tested pipe, one of which is equipped with drain and discharge unions. Then, tests are carried out in pipe specimen on durability by loading with cyclic internal pressure in range of minimum pressure P_min to maximum pressure P_Max, wherein P_max corresponds to maximum overpressure in pipeline operation in normative mode P_norm, and value P_min does not exceed 0.1 P_max, and cyclic bend of pipe specimen by application to it of bending moment with change of excess bending radius ρ_bend of natural sample in range of 40D_N < ρ_bend < 1,000D_N, where D_N is outer diameter of tested pipe. At that, loading by internal pressure is performed with preset frequency ω_p, and frequency ω_bend of natural sample loading by cyclic bending is in range of 0.003 ω_p < ω_bend < ω_p. Natural pipe specimen tests for durability are carried out until natural sample destruction or depressurisation. By results of tests of pipe specimen parameters which determine its durability are recorded: number of loading cycles N, value of maximum and minimum pressure and/or bending moment to destruction or depressurisation in pipe specimen.

EFFECT: technical result is possibility of testing imitating excess modes of operation of oil pipeline.

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