RU2484357C1 - Resilient shell for pipeline shutdown - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: resilient shell comprises cylindrical and two end parts and compressed air feed pipe. Cylindrical part outer surface is provided with a set of sealing annular ledges and separate annular ledge located closer to end part than said set of ledges for pressure to applied to said separate ledge in operation. Said separate ledge is located from extreme ledge of said set at the distance larger than that between ledges of the set and features height exceeding that of set ledges.

EFFECT: better tightness.

5 cl, 6 dwg

Description

The invention relates to pipeline transport and can be used to shut off oil pipelines and oil pipelines.

Currently, sealants and pneumatic plugs are used, which are a closed cylindrical rubber-cord shell with a valve for connecting to a source of compressed air.

Known elastic shell for tight shutoff of the pipeline, containing a cylindrical and two end parts, a fitting pipe and a pneumatic pipe for pumping with compressed air, connected to the fitting (see RF patent No. 102742, publ. 10.03.2011).

The closest analogue to the proposed invention is an elastic shell for tight shutoff of the pipeline, containing a cylindrical and two end parts, a fitting for supplying compressed air, while on the outer surface of the cylindrical part a group of sealing ring protrusions is made (see RF patent No. 90526, publ. 10.01 .2010).

A disadvantage of the known technical solution is incomplete sealing of relatively large irregularities on the inner surface of the pipeline — welds, shells and growths, the dimensions of which are comparable with the height of the sealing protrusions. This is especially true when bumps cross several sealing tabs in a row.

Due to the fact that the annular grooves are made between the protrusions imperfectly (within the tolerance) in diameter, defects in the mold material, shrinkage of the rubber after vulcanization, and also the operating conditions of the sealant itself, the height difference of the sealing protrusions along the axis of the pipe can reach 1.5 mm, which with a deformation of the sealing protrusions equal to 2-3 mm and a height of the weld up to 4 mm creates the possibility of local lack of sealing and, accordingly, breakthrough of combustible gases or liquids in the pipeline repair area, leading about to an emergency.

In addition, in case of leaky overlap of the inner cavity of the pipe, the overlapping medium penetrates into the space between the sealing protrusions and the inner surface of the pipe, which leads to a decrease in the degree of deformation of the protrusions due to the squeezing of the shell wall from the inner wall of the pipe, a decrease in the friction force between the shell and the pipe and , to a decrease in the pressure of the overlapping medium that the shell can hold.

A decrease in the friction force leads to a shear shift to the area of repair work. A decrease in the degree of deformation leads to depressurization of the damping device and a breakthrough of the damped medium and its vapors into the area of repair work. Both factors are fraught with emergency.

The objective of the invention is to prevent the penetration of the transported liquid and its vapors into the area of repair, welding and other firing and construction works.

The technical result of the claimed invention is to improve the quality of sealing relative to large irregularities on the inner surface of the pipeline.

The technical result of the invention is achieved due to the fact that the elastic shell for tight shutoff of the pipeline containing a cylindrical and two end parts and a fitting for supplying compressed air, while on the outer surface of the cylindrical part a group of sealing ring protrusions is made, according to the change on the outer surface contains a separate annular a protrusion located closer than a group of protrusions to the end part, subjected to a pressure condition in the working state, spaced from the extreme protrusion pas band by a distance greater than the distance between the protrusions group and having a height greater than the height of the group of protrusions.

Preferably, each annular protrusion of the group has an isosceles triangle section, and a separate annular protrusion has a section in the form of a triangle or trapezoid, the sides of which facing the end part of the shell and the group of ring protrusions are angled to the radius of the cylindrical part of the shell α and β respectively, with α <β.

Preferably, the angle γ is selected from 50 ° to 90 °, the angle α is from 5 ° to 15 °, and the angle β is from 30 ° to 50 °.

The invention is illustrated by drawings, where:

figure 1 shows a well-known elastic shell, front view;

figure 2 shows the proposed elastic shell, front view;

figure 3 shows a fragment of the proposed elastic shell (view A in figure 2);

figure 4 shows the proposed elastic shell installed in the pipeline, front view;

figure 5 shows a fragment of the proposed elastic shell with sealing protrusions after its deformation in the pipeline (type B in figure 5);

figure 6 shows a fragment of the cross section of the shell at the place of sealing of the weld seam spaced annular protrusion.

The proposed elastic shell for tight shutoff of the pipeline contains a cylindrical part 1 and two end parts 2, 3, one of which is attached to the shank 4 of the coupling device. The fitting for supplying compressed air is not shown in the drawings.

On the outer surface of the cylindrical part 1 of the shell, a seal is made in the form of a group of sealing annular protrusions 5 of a triangular section. Also, on the outer surface of the cylindrical part 1 of the shell, a separate annular protrusion 6 is made, which is closer than the group of protrusions 5 to the end part 2, which is exposed to pressure in the working state and is spaced apart from the extreme protrusion 5 of the group more than the distance between the protrusions of group 5 , and having a height exceeding the height of the protrusions of the 5th group (see figure 3).

The shell is installed in such a way that the end part 2, closer to which there is a separate protrusion 6, is subjected to the pressure of the transported medium.

In the drawings are indicated:

figure 1, 2:

L _ref. - the length of the shell in the initial state;

L _cont. - the length of the contact spot of the shell with the inner surface of the pipe;

L _rep. - the length of the zone of the annular sealing protrusions 5;

D _ref. - the initial diameter of the elastic shell;

figure 3:

a - the distance between the protrusions in the group of sealing protrusions 5;

b - the distance between the stand-alone sealing protrusion 6 and the first sealing protrusion 5 in the group;

l ₁ - the length of the pressure zone of compressed air in the shell on one sealing protrusion 5 in the group;

l ₂ - the length of the pressure zone of compressed air in the shell on a separate sealing lug 6;

H ₁ - the initial height of the sealing protrusion 5 in the group of protrusions;

H ₂ - the initial height of the individual sealing ledge 6;

figure 4:

L _cont. - the length of the contact spot of the shell with the inner surface of the pipe;

P _environment - the pressure of the medium on the elastic shell;

P _slave. - working pressure in the elastic shell;

D _slave. - working diameter of the elastic shell;

d _pipe - the inner diameter of the pipeline 7;

figure 5:

l ₁ - the length of the pressure zone of compressed air in the shell on one sealing protrusion 5 in the group;

l ₂ - the length of the pressure zone of compressed air in the shell on a separate sealing lug 6;

h ₁ - the height of the sealing protrusion 5 in the group after deformation;

h ₂ - the height of the individual sealing protrusion 6 after deformation (plug in working condition);

Δh ₁ - the amount of deformation of the sealing protrusion in the group of protrusions;

Δh ₂ - the amount of deformation of a separate sealing protrusion;

figure 6:

h _stitch - the height of the weld;

h _{upl. max.} - the maximum height of a separate sealing protrusion 6 after deformation in the weld zone.

The elastic shell works as follows.

An elastic sheath for tight shutoff of the pipeline 7 is moved along the pipeline 7 with the help of the coupling device 4 to the place of repair. An angled fitting (not shown) is fixed in the hole made in the upper part of the wall of the pipeline 7, and compressed air is pumped into the shell through the pneumatic pipeline. The shell is inflated, adjoins its cylindrical part 1 to the wall of the pipeline 7 and hermetically closes the internal cavity of the pipeline 7.

Sealing of relatively large irregularities on the inner surface of the pipeline 7 — welds, sinks and growths — is provided by a separate annular protrusion 6, the first on the side of the transported medium, separated from the extreme protrusion of group 5 by a distance greater than the distance between the protrusions of group 5 and having a height exceeding the height of the protrusions of group 5.

Since a separate annular protrusion 6 is spaced from the extreme protrusion 5 by a distance 6 greater than the distance a between the protrusions 5, the length l _{2 of} the compressed air pressure zone in the shell by a separate sealing protrusion 6 exceeds the length l _{1 of} the compressed air pressure zone in the shell by one sealing ledge 5 in the group. This allows you to significantly increase the shell wall area along the length l ₂ , transmitting the pressure P _{slave of} compressed air in the shell, and, accordingly, the pressure force on this separate protrusion 6, which leads to an increase in the degree of deformation Δh _{2 of the} sealing protrusion 6 with sufficient rigidity of the shell wall, thickness commensurable with the height H ₂ of a detached annular projection 6, and provides a reliable sealing of the overlap zones and recesses located between the weld surface and the inner cylindrical surface of the pipe (with FIG. 6).

This also applies to pipe defects in the form of growths or shells.

Preferably, each annular protrusion 5 of the group has a cross section in the form of an isosceles triangle, and a separate annular protrusion 6 has a cross section in the form of a triangle or trapezoid, the sides of which facing the end part of the shell and the group of annular protrusions 5 are angled to the radius of the cylindrical part 1 the shells α and β, respectively, with α <β.

The angle γ at the apex of the isosceles triangle, the shape of which preferably has a cross section of each annular protrusion 5, is preferably selected from 50 ° to 90 °, angle α is from 5 ° to 15 °, angle β is from 30 ° to 50 °.

Preferably, the separate annular protrusion 6 has a section in the shape of a triangle or trapezoid. This geometry of the protrusion 6 allows you to additionally withstand the pressure P of the _{medium of the} transported fluid on the elastic shell, the penetration of the transported fluid and its vapors into the area of repair, welding and other firing construction work, which improves the quality of sealing relatively large irregularities on the inner surface of the pipeline 7.

Claims (5)

1. An elastic shell for tightly shutting off the pipeline, comprising a cylindrical and two end parts and a fitting for supplying compressed air, while on the outer surface of the cylindrical part a group of sealing annular protrusions is made, characterized in that a separate annular protrusion located closer to the outer surface is made, than a group of protrusions, to the end part, which is subjected to pressure under operational conditions, and which is spaced apart from the extreme protrusion of the group by a distance greater than the distance between the protrusions PAMI group and having a height greater than the height of the group of protrusions. 2. The elastic shell according to claim 1, characterized in that each annular protrusion of the group has a cross section in the form of an isosceles triangle. 3. The elastic shell according to claim 1, characterized in that the separate annular protrusion has a section in the form of a triangle or trapezoid, the sides of which, facing the end part of the shell and the group of annular protrusions, are located at angles to the radius of the cylindrical part of the shell α and β, respectively , while α <β. 4. The elastic shell according to claim 2, characterized in that the angle γ is selected from 50 ° to 90 °. 5. The elastic shell according to claim 3, characterized in that the angle α is selected from 5 ° to 15 °, and the angle β is from 30 ° to 50 °.

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