Collar for an inspection or cleaning pig

Abstract

A collar for a cleaning or inspection pig which is movable in a pipeline and through the latter. The collar may include an inner fastening region, with respect to a longitudinal center axis of the collar, for fixing the collar to the cleaning or inspection pig. The collar may also include a contact region which is provided for contact against a pipe wall and which is part of an outer segment which is connected to the inner fastening region. The inner fastening region is preferably in advance of the contact region with respect to a direction of movement (F) of the pig. The collar comprises an anchoring segment, the first end of which is arranged on the outer segment and the other, second end of which is arranged, with respect to the longitudinal center axis, further toward the latter and trailing the first end with respect to a direction of movement of the pig. A pig for cleaning or inspecting pipeline pipes may also be provided.

Claims

1. A collar for a cleaning or inspection pig which is movable in a pipeline, said collar comprising: an inner fastening region with respect to a longitudinal center axis of the collar, said inner fastening region fixing the collar to the cleaning or inspection pig; a contact region which is provided for contact against a pipe wall and which is part of an outer segment which is connected to the inner fastening region; an anchoring segment having a length extending between a first end and a second end, the first end of which is arranged on the outer segment proximate the contact region, and the second end of which is arranged radially inwardly of the contact region and upstream of the first end with respect to a direction of movement of the pig, the anchoring segment being connected to at least one of the collar and pig only at the first end and second end connections such that a remainder of the length of the anchoring segment is not connected directly or indirectly to the pig or collar; wherein relative positioning and connections between (a) the contact region and anchoring segment, and between (b) the outer segment and the anchoring element, being such that upstream pressure causes the anchoring segment to pull radially inwardly on the contact region, thereby decreasing pressure applied by the contact region to the pipe wall; wherein the inner fastening region is preferably in advance of the contact region with respect to a direction of movement (F) of the pig.

2. The collar as claimed in claim 1, wherein the anchoring segment is arranged on the outer segment at a distance from the contact region in the direction of the longitudinal center axis, and the second end is fixable or is fixed on the fastening region or on a pig part.

3. The collar as claimed in claim 1, wherein the anchoring segment at least partially forms a cavity proximate at least one of the outer segment and the inner fastening region.

4. The collar as claimed in claim 3, wherein the collar has a pressure-equalizing opening which, with regard to a direction of movement (F), leads from a front of the collar to the cavity.

5. The collar as claimed in claim 1 wherein the anchoring segment is formed with at least one joint for the forced guidance of individual anchoring segment sections.

6. The collar as claimed in claim 5, wherein the anchoring segment has at least two joints; wherein an anchoring segment section located between two joints is designed to be thicker than at least one of the joints.

7. The collar as claimed in claim 1 wherein the anchoring segment has a fastening flange at its second end for introducing into a region of complementary design.

8. The collar as claimed in claim 1 wherein the anchoring segment has thin regions in a circumferential direction for improved adaptation to different pipe inside diameters.

9. The collar as claimed in claim 1 wherein the collar is produced integrally with the anchoring segment.

10. A pig for cleaning or inspecting pipeline pipes, said pig comprising a collar as claimed in claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

(2) FIG. 1 shows a partial sectional view of a device according to the prior art.

(3) FIG. 2 shows a partial sectional view of a device 30 according to the invention.

(4) FIG. 3 shows further subject matter according to the invention in a partial sectional view.

(5) FIG. 4 shows further subject matter according to the invention in a partial sectional view.

(6) FIG. 5 shows further subject matter according to the invention in a partial sectional view.

(7) FIG. 6 shows further subject matter according to the invention in a partial sectional view.

(8) FIG. 7 shows a partial view of further subject matter according to the invention in a perspective illustration.

DETAILED DESCRIPTION OF THE DRAWINGS

(9) Individual technical features of the subsequently described exemplary embodiments can also be combined in combination with previously described exemplary embodiments and the features of the independent claims and possible further claims to form subject matter according to the invention.

(10) Subject matter according to the preamble of claim 1 is shown in FIG. 1 in a partial sectional view which illustrates an upper part of a pig according to the invention. The pig, which is illustrated only by a front region, moves in the direction F through a pipeline, of which one wall 1 is partially illustrated. A collar according to the invention for said pig, which is designed as a cleaning or inspection pig, has a longitudinal center axis 2 around which the collar 3 is formed. The longitudinal center axis 2 points in the direction of a longitudinal center axis of the pipeline.

(11) The collar 3 has an inner fastening region 6 which is fastened to a pig body 4, and a contact region 7 which is shown by chain-dotted lines, is directed toward the pipe wall and presses against an inside 8 of the pipe wall 1. In the relaxed form of the collar, the contact region 7 would be deployed further outward as contact region 7. The contact region 7 or 7 is part of an outer segment 9 which, in the present case, is connected to the inner fastening region 6 via a thin point 11. The collar 3 is a customary cup, as is known from the prior art.

(12) In the event of a differential pressure increase because of a slowing down of the movement of the pig, an additional force component is produced in the direction of the arrow D, said force component resulting in an increase in the friction against the pipe wall 1.

(13) A pig according to the invention or a collar 3 according to the invention has an anchoring segment 12 which comprises a first end 13, which is arranged on the outer segment 9, and a second end 14 which is arranged on the pig body 4 and therefore toward the longitudinal center axis 2 (FIG. 2). Furthermore, said second end 14 is arranged upstream of the first end 13 with regard to a direction of movement F, By means of this arrangement, in the event of a differential pressure increase because of a situation in which the pig moves more slowly or even becomes stuck in the pipeline, an additional force component is produced in the direction D toward the longitudinal center axis 2, said force component opposing a force component in the direction D, if present. The pig can therefore move more uniformly through the pipeline, since the pig already continues in the event of relatively small differential pressures, and therefore the resulting differential speeds should overshooting occur turn out to be smaller.

(14) The anchoring segment 12 according to the invention which, precisely like the outer segment 9 and the fastening region, is arranged in an encircling manner around the longitudinal center axis 2, comprises a total of three joints 17 in the form of film hinges which bound two thicker anchoring segment sections 16.

(15) The joints 17 are designed as thin points. At the end 14, the anchoring segment 12 furthermore has a fastening flange 18 which is inserted in a corresponding recess of the pig body 4 and is fixed in said recess via a fastening means 19. A multiplicity of such fastening means, which are preferably in the form of screws, are present in the circumferential direction around the longitudinal center axis 2.

(16) A pressure-equalizing opening 21 leads into a channel 22 via which a cavity 23 is equalized in terms of pressure with the region located in front of the pig.

(17) The anchoring segment 12 is not arranged at the outermost end of the collar 3, with regard to a radial extent of same, but rather is offset further inward, and therefore, as viewed in the longitudinal direction F, a part of the collar 3 is approached directly by the medium, whereas a predominant part of the medium no longer flows against an inner surface 24 of the inner fastening region or of the outer segment of the collar 3, but rather against the anchoring segment 12.

(18) In the exemplary embodiment according to FIG. 3, a cup is likewise again developed in accordance with the invention, wherein the anchoring segment here has an additional anchoring segment section 16 which is likewise again of thickened design and is connected to the rest of the anchoring segment 12 via joints 17 forming film hinges. The exemplary embodiments of FIGS. 2 and 3 are provided with collars 3 which are manufactured integrally from polyurethane.

(19) In the exemplary embodiment of FIG. 4, the anchoring segment is provided with rigid sections 27 which are connected to one another via joints 26. This may involve an exemplary embodiment according to FIG. 3. However, anchoring segment parts may also be involved that are actually not produced integrally with the rest of the collar, but rather are composed of a different material and the joints of which are designed to be movable to a limited extent corresponding to the opening of the respective half shells 28. In the exemplary embodiment according to FIG. 5, the anchoring segment is formed by a membrane 30 which is pliable and which can buckle under the action of pressure. A roller 29 is provided on the outer side, the roller allowing for rolling along a pipe inner wall.

(20) A conventional disk can likewise be provided with an anchoring segment 12 in the form of a membrane 30, as is illustrated in FIG. 6.

(21) In a circumferential direction about the longitudinal center axis 2, a pig according to the invention can be provided with a collar 3 which has an anchoring segment 12 which comprises thickened anchoring segment sections 16 which are separated from one another by thin regions 31 (FIG. 7). A compression of the collar 3 is thereby possible in an improved manner, since the anchoring segment 12 is formed in a flexible manner by means of the thin regions 31.