METHOD TO ASSESS TECHNICAL CONDITION OF INSULATION COATING OF UNDERGROUND PIPELINE Russian patent published in 2012 - IPC F16L58/00 

FIELD: electricity.

SUBSTANCE: in the method a pipeline section is selected, arranged between points of drainage of two adjacent cathode protection stations (hereinafter referred to as CPS), where coating condition is to be assessed. A grade of pipe steel, from which a pipeline is made, is determined, as well as types of soil at the depth of the pipeline installation. In laboratory conditions, values are serially measured for natural difference of "metal-soil" potentials with the help of steel samples, the grade of which is identical to the grade of pipe steel within an inspected section, placed into soil identical to the type of soil in the area of pipeline installation. The difference of "pipe-earth" potentials is determined, as well as current forces at the outlet of the CPS, and protective potential shift. The value of polarising current force is accepted as equal to a half-sum of current force values at the outlet of each CPS. On the basis of the produced data, transition resistance of insulation is determined, by the value of which the technical condition of the inspected pipeline section is determined.

EFFECT: spreading of technical measures range.

1 dwg