METHOD OF INTER-PIPE DIAGNOSTICS PERFORMANCE IN A MOBILE LIQUID PLUG Russian patent published in 2018 - IPC G01N29/04 

FIELD: defectoscopy.

SUBSTANCE: using to detect defects in the pipeline wall. Summary of the invention consists in the fact that equipped with transmitters whose signals are received and processed at ground processing stations the in-line inspection instrument is moved through a pipeline, at that, the in-line inspection instrument (III) is moved through a pipeline in a movable liquid plug, for creation of which a first external separator piston is inserted into the pipeline launch chamber, filling the launch chamber with the movable liquid plug liquid medium and starting the first external separator piston, then the first internal piston separator is inserted into the launch chamber, filling the launch chamber with the movable liquid plug liquid medium and starting the first internal separator piston, then an in-line inspection instrument is inserted into the pipeline launch chamber, launch chamber is filled with the movable liquid plug liquid medium and starting the in-line inspection instrument, after that, a second internal separator piston is inserted into the launch chamber, the launch chamber is filled with the movable liquid plug liquid medium and the second internal separator piston is launched, then a second external separator piston is inserted into the launch chamber and an external separator piston is launched, after which the of movable liquid plug mobile liquid plug is launched through a pipeline, at that, observing the condition of equality of the frictional forces of the support elements of the in-tube inspection device and the friction forces of the support elements of all separator pistons to the inner wall of the pipeline.

EFFECT: broader functional capabilities of all types of IIIs, originally intended for in-line inspection of main pipelines with movement with the flow of pumped liquid product, as well as the use of IIIs that are not intended for operation in a gas environment, for in-line diagnostics of gas mainlines.

21 cl, 3 dwg