RU2770170C1 - Apparatus for determining the locations of defects in insulation coating on pipelines laid under water obstacles - Google Patents

Abstract

FIELD: measuring equipment.SUBSTANCE: apparatus for locating defects in insulation coating on pipelines laid under water obstacles consists of non-polarising comparison electrodes, a frame, a cable railway cable, a winding apparatus, a drum, a cable length meter, a recording apparatus, wherein the non-polarising comparison electrodes are rigidly fixed on the frame, each electrode of the frame is connected with a wire bundle, all connections of wires with comparison electrodes are tightly sealed, and said frame is secured on the cable of the cable railway passing over the pipeline between supports located along the shores of the water obstacle above the axis of the pipeline.EFFECT: possibility of simultaneously measuring the longitudinal and transverse potential gradients of the pipeline at an underwater crossing at a predetermined step, identifying defects in insulation coating, and registering the location thereof on the pipeline relative to the nearest control and measuring point.3 cl, 2 dwg

Description

The device for determining the location of defects in the insulating coating on pipelines laid under water barriers refers to the system for determining the location of defects in the insulating coating on pipelines laid under water barriers.

The closest to the claimed technical solution are: the BITA-1 non-contact current measurement complex [1], the Poisk 021 instrument kit [2] and the KORD-IPI insulation damage indicator [3].

A significant limitation in the use of each of these devices is the use of a special signal generator of a given frequency, which requires connection to the pipeline. It is also a limitation that work to determine the location of a defect in the insulating coating of a pipeline laid under a water barrier is possible only in the winter period, i.e. "from the surface of the ice."

The technical problem solved with the help of the claimed technical solution is the creation of a device that allows to carry out work to determine the location of defects in the insulating coating on pipelines laid under water barriers during the absence of ice cover (spring-autumn period) along the longitudinal and transverse potential gradients simultaneously . This eliminates the possibility of obtaining erroneous data in the detection of a defect in the insulating coating and allows you to accurately fix its location on the pipeline relative to the nearest support without connecting any signal generator to the pipe.

The technical result that can be achieved using this technical solution is to create a frame made of a dielectric material (for example, from a PVC pipe or a polypropylene pipe) of an integral welded structure in the form of a right triangle with non-polarized reference electrodes located at the corners of the triangle at a fixed distance from each other. from a friend and a funicular installed above the axis of the surveyed pipeline with supports along both banks of the water barrier. The supports are designed to hold the frame above the axis of the pipe with the frame fixed on the funicular cable and to control the distance of the frame movement along the axis of the pipeline. This allows you to simultaneously measure the longitudinal and transverse potential gradients of the pipeline at the underwater crossing with a certain step, determine the defects in the insulating coating and fix their location on the pipeline relative to the nearest control and measuring point.

In FIG. 1 and FIG. 2 shows a device for determining the location of defects in the insulating coating on pipelines laid under water barriers. The device for determining the location of defects in the insulating coating on pipelines laid under water barriers, shown in the drawings, consists of a funicular support with a pulley 1, a funicular support 2 with a drum, a triangular frame 3, non-polarized reference electrodes 4, 5, 6, a wiring harness from the reference electrodes 7, the winder of the cable harness and the funicular cable 8, the cable car cable 9, the cable car drum 10, the cable length counter 11 and the recording device 12.

The device consists of a frame 3, which is made in the form of a right triangle. Identical non-polarizable reference electrodes 4, 5, 6 are fixed at the corners of the frame 3. From each non-polarizable reference electrode 4, 5, 6, one wire comes out into the common wiring harness 7. All wire connections with reference electrodes 4,5,6 are sealed. A common wiring harness 7, a winder for the cable harness and funicular cable 8, combined with a cable length counter 11, a recording device 12 and a drum 10, are combined in a single housing 13 and is located on a support 2. One of the legs of the frame 3 is located parallel to the axis of the pipeline and along its corners are fixedly connected to the funicular cable 9. The funicular 9 is located strictly above the pipe with supports 1 and 2 on opposite banks of the water barrier.

The device works as follows.

The axis of the pipeline is determined on each bank of the water barrier and supports 1 and 2 are installed above the axis of the pipeline so that the funicular cable 9 is above the axis of the underwater pipeline. The frame 3 is fixed to the funicular cable 9 rigidly, without slipping, and placed in the water next to the support 2, combined with the funicular cable winder 8 so that on the frame 3 two non-polarized reference electrodes 4, 5 are above the pipeline and parallel to the axis of the pipeline, and the third non-polarizable reference electrode 6, located in the corner of frame 3, was directed at an angle of 90 degrees to the axis of the pipeline and directed downstream, if any. The counter 11 in the housing 13 is set to zero, the recorder 12 is turned on and the first measurement of the longitudinal and transverse potential gradients is made. Each subsequent measurement can be carried out discretely, or continuous recording, if the recording device 12 allows. After discrete measurements with a step of 2 meters (or continuously) across the entire width of the water barrier, the information obtained is removed from the recording device 12 for further study. According to the magnitude of the measured potential gradients, the presence of defects in the insulating coating of the pipeline is judged. It is possible to use a voltmeter with a high input resistance instead of the recording device 12, in which case the gradient value is recorded manually in a workbook.

The use of the claimed device for searching for defects in the insulating coating on pipelines laid under water barriers achieves high accuracy in detecting defects in the insulating coating.

The device for searching for defects in the insulating coating on pipelines laid under water barriers is different:

- relative simplicity of design, unpretentiousness in handling, the possibility of long-term and repeated use;

- simultaneous obtaining of the values of the gradients of the longitudinal and transverse potentials and determining the location of defects in the insulating coating on the pipeline in the channel part of the underwater crossing with reference to the nearest control and measuring point;

- the possibility of carrying out work on the inspection of pipelines in the warm season;

- no need to use a pulse generator and a power source (or a cathodic protection station).

Literature

1. BITA-1 Complex for non-contact current measurement in underground gas pipelines. Manual. DSSHK. 412239.001 RE.

2. Product catalog of Parsek LLC. Devices and systems for corrosion monitoring and electrochemical protection against corrosion. 2017 Complex of devices "Poisk-021".

3. Insulation damage indicator KORD-IPI-02. Manual.

Claims (3)

1. A device for searching for defects in the insulating coating on pipelines laid under water barriers, consisting of non-polarizable reference electrodes, a frame, a funicular cable, a winder, a drum, a cable length counter, a recording device, while non-polarizable reference electrodes are rigidly fixed to the frame, each the frame electrode is connected to the wire harness, all wire connections to the reference electrodes are sealed, and the specified frame is fixed on the funicular cable passing over the pipeline between supports located along the banks of the water barrier above the pipeline axis. 2. The device according to claim 1, characterized in that there are three non-polarizable electrodes. 3. The device according to claim 1, characterized in that the non-polarizable electrodes are replaceable.

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