SU1214984A1 - Method of determining location of pipeline defects - Google Patents

Description

"

The invention relates to non-debugging inspection and can be used to determine the location of damage to the walls of the pipework during its inspection using a magnetic flaw detector.

The aim of the invention is to increase the accuracy of determining the location of defects by setting markers on the pipeline before putting it into operation and changing their number or location in each subsequent section.

FIG. 1 schematically shows a pipeline with gauges located on it; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4 shows a section B-B in FIG. one; in fig. 5 shows an example of recording signals on a recorder tape.

The markers 1 are installed in certain places (rappers) on the outer surface of the pipeline 2 along its length, while the markers are fixed on the pipeline before it is commissioned permanently and are placed on each frame in its characteristic circumference in one (for example, t, p) or several (for example, reper 1) pipeline cross-sections. Markers are located at a certain distance й | from welds 3, 4 and 5,

The marker can be made in the form of plates of ferromagnetic material and attached to the pipeline 2, by welding. Markers are installed on the pipeline when it is constructed or when it is entered into the routine inspection mode by the flaw detection complexes.

As markers, magnetic, radiation, acoustic and other elements and devices can also be used.

FIG. 2 shows the location of four markers, typical only for frame m, in one section of the pipeline; in fig. 3 - location through 45 ° of three markers in one section of the pipeline, characteristic only for the frame n; in fig. 4 - location of the markers in two sections of the pipeline, characteristic only for the frame i. Four crossbars are fixed in each section.

842

through 90, while in the second section the markers are shifted relative to

/ with the first section markers at 4;).

The distance t (Fig. 1) between the sections should provide a clear distinction between the signals from them, recorded by the sensors and recorded on the recorder tape of the instrument during inspection of the pipeline.

The number of markers placed in one section must be less than the number of tracks on the tape of the recorder, to distinguish them from the signals of the annular weld of pipes, which

Firms on all tracks of the storage media.

The sensors are located on the flaw detector evenly around the circumference, near the inner surface of the pipeline walls, and each flaw detector sensor provides a signal for recording on a specific track of the recorder tape.

FIG. 5 shows an example of a short length 8-track register. RATOR 6 and recording signals from changes in the magnetic field near the locations of the benchmarks t, n, i. When decrypting recordings on tape

Recorder 6 can clearly identify groups of recorded signals typical for each reper (t, n, i), signals from circular welds 3, 4 and 5, single signals from pipeline defects (X, Y, Z) detected only by some sensors, marks S traveled by the flaw detector for a distance of 1 m.

When inspecting pipeline 2, the role of the markers 1 is to change the magnetic field against the walls of the pipeline created by the magnetization device of the flaw detector moving inside the pipeline. Signals from these changes (ha, p, i), as well as signals from changes in the magnetic field caused by welds 3, 4 and 5 and defects in the pipeline walls (X, Y, Z), are recorded by sensors and recorded on tape 6 To find the location of p; any pipeline defect, for example defect Z,

determine on the tape of the recorder 6 (Fig, 5) the closest to this defect reference point (in this case reference point i), the number of welds from the reference point

i to the closest to the desired defect Z of the weld 5 (two welds 4 and 5), according to the marks of the traversed path S is the distance C3 from the weld 5 to the desired defect Z,

Know from pipeline documentation the exact location of the rapper

i along the length of the pipeline iXj (Fig. 1), distance S, from this frame to seam 4 and pipe length f. between welds 4 and 5, with a high degree of accuracy, we determine the location of the defect Z.

A a

225

B-s

five

90 t

13S

Defect x Defect Y

Editor N.Shvyschka

Compiled by D. Varrick Techred 3. PALIUS

Order 898/50 Circulation 460 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

Defect 2

(rig 5

Proofreader M.Maksimishinets

Claims (2)

1. METHOD FOR DETERMINING THE LOCATION OF PIPELINE DEFECTS by installing markers in certain sections along the length of the pipeline on its outer surface and inspecting the pipeline using a flaw detector, which differs in that, in order to increase the accuracy of determination, the markers are installed on the pipeline before entering it into operation, while changing the number or location of the markers in each subsequent section. 2. The method of claim 1, wherein ^- 'u and I th with that timers set the offset as the diameter of the pipeline and along its axis. _with ss Reference, t Reper, p Reper ί 77722 222 272 222 7/72/22/222222 222L J / 1 22/777 7/7/77 / 2 ~ Ί ♦ ⁵ 1 I „y \ 772 722 \ ---- cq ---- rq. IN θ --CZJ ----- / IN u ί ‘' U ⁷ 2 Li _f l - lz FIG. ι