The task is to estimate the period of technological pipelines safe operation depending on the total influence of oil refining equipment technical parameters. 9 feature properties of technological pipelines were singled out, and the estimation was made with the help of such indicator as the residual life of pipelines. The authors constructed a mathematical model, calculated the diagnostic coefficients and informative character of the characteristic for each period accepted by the expert. A mechanism for estimating the safe operational lifetime of pipeline systems is proposed. Conclusions were drawn about the advisability of applying the proposed method for solving this class of problems.