Behavior of a Double-Layer Pipeline Under Static Load

The authors investigated the features in the behavior of various components of "pipe in pipe" system when changing the internal pressure in the annular space. During the research, the dependence of plastic pipe creep modulus on tensile stress was received. Using a method of least squares, the authors calculated the empirical coefficients for dependences of plastic pipe creep modulus on pipeline service period and stresses in the pipe material caused by static load. They revealed an unequivocal relationship between the parameters of a double-layer pipeline with the maximum use of plastic or steel pipelines resistance.