Overhead gas Pipeline Diagnostics

The technology developed by us for the above-ground technical diagnostics of gas pipelines provides, basically, the following. First, damage to the insulation coating, the depth of the gas pipeline and its position are contactlessly determined, the effectiveness of electrochemical protection is checked, and corrosion-hazardous areas and areas with abnormal mechanical stress in the metal are detected. We have created and tested together with CJSC VNIIST-SEARCH a new complex of overhead diagnostics of pipelines "M-1", which allows simultaneous electrometric, magnetometric and other measurements, GPS tracking, and thereby increase the efficiency of detecting corrosive zones and zones concentration of mechanical stress.

Then, based on the results of these works, in the most dangerous zones, they are pitted and carried out a detailed examination of the insulation and metal state of the gas pipeline, as well as control of welded joints in these places with the determination of the physicomechanical properties of the pipes.

A large amount of work to diagnose gas pipelines falls on the assessment of the technical condition of pipes during the overhaul of the insulation coating (re-insulation). In the gas industry, work was initiated to create automated scanners for 100% control of the pipe body after stripping. For this purpose, we used automatic scanning magnetic flaw detectors.

To quantify the mechanical stresses in the pipe in the field, we used a portable X-ray diffractometer of the Stressrad type. We propose using the X-ray diffractometry method as the main method for assessing the stress-strain state of pipelines in the field, because it gives the most reliable information about stresses in the surface layer of metal.

Based on the results of a comprehensive technical diagnosis, measures are developed that ensure the safe operation of gas pipelines, and a date is set for the next diagnosis. As confirmed by the practice of recent decades, this allows for the operation of gas pipelines according to their technical condition. In order to increase the reliability of the assessment and forecast of the technical state of gas pipelines, it is advisable to conduct, where possible, simultaneous in-line flaw detection and ground-based diagnostics.