METHOD OF CUTTING AND CLOSING PIPELINE UNDER PRESSURE Russian patent published in 2019 - IPC B23P6/00 F16L41/04 

FIELD: transportation.

SUBSTANCE: invention relates to pipeline transport and can be used in repair of distribution network pipelines with operating pressure ≤1,2 MPa without stopping transfer of transported medium. Method involves installation of welding fittings on pipeline, installation of gate valves on them, installation of drilling device with closed slide valve and cutting holes in pipeline with open valve, installation of cleaning device and cleaning inner surface of pipeline through hole in pipeline, installation of blocking device to shut off pipeline section, installation of bypass line on this section. Drilling, cleaning and blocking devices are installed on additional header with flanges. Lower flange of collector is connected to flange of gate valve, and on upper flange is fixed in turn drilling device and metal discs installed by means of spherical hinged connection on rods of cleaning devices and locking device for movement of working units of these devices in longitudinal and transverse direction during installation in pipeline. Spherical articulated joint is made in the form of a fixed body and a ball head with an external surface repeating the inner spherical surface of the body and having an axial cylindrical hole. When said devices are installed, pressure is leveled higher and lower than the slide valve by means of bypass valve of the slide valve. Residual pressure is discharged through collector bleed pipe with shutter valve closed, and bypass line is installed on manifold branch pipes.

EFFECT: result is faster operation of method, unification of installation of used equipment for pipelines of different diameters, higher quality of blocking pipeline section.

6 cl, 7 dwg