METHOD FOR DETERMINING PIPELINE SERVICE LIFE Russian patent published in 2014 - IPC F17D1/00 

FIELD: machine building.

SUBSTANCE: method consists in the quantitative assessment of pipeline damageability as an operating time function. Service life at the stage of operation is determined by the correction of the design service life. In case a pipeline was overhauled, the service life is determined as $${Т}_{sl}^o=\frac{{Т}_{sl}^p}{m_{\min }-\frac{\mathrm{1,26}}{\exp \frac{1}{N_r}}}+{Т}_{opov},$$ where $$T_{sl}^p$$ stands for the service life defined at the design stage, m_min - for minimal life shortening factor, N_r - for the relation of the amount of replaced pipes to the total amount of pipeline pipes, T_opov - pipeline operating time by the moment of overhaul performance. Otherwise where possible the in-line technical diagnostics is carried out for certain pipeline sections and fraction number of defective pipes and operating condition index are defined. At a pipeline with no pig traps installed, the corrosion inspection is carried out by measuring the current induced in the pipeline by an external source, along the pipeline route with the step not exceeding 10 m. On the basis of the obtained data, the integral operating condition index for the whole pipeline P_cond is defined and its value is used for the determination of the service life at the stage of operation as $${Т}_{sl}^o=\frac{{Т}_{sl}^p}{k_{ls}}=\frac{{Т}_{sl}^p}{m_{\max }-{\left(\frac{1}{\exp {Р}_{cond}}\right)}^{\frac{{Т}_{sl}^p}{{Т}_{op}}}},$$ where k_ls stands for the life shortening parameter, m_max - maximal life shortening factor, T_op - the pipeline operating time.

EFFECT: invention allows for more accurate determination of a pipeline service life at the stage of its operation.

6 tbl, 2 dwg