GB2242530A - Pressure testing of pipeline welds - Google Patents
Pressure testing of pipeline welds Download PDFInfo
- Publication number
- GB2242530A GB2242530A GB9006819A GB9006819A GB2242530A GB 2242530 A GB2242530 A GB 2242530A GB 9006819 A GB9006819 A GB 9006819A GB 9006819 A GB9006819 A GB 9006819A GB 2242530 A GB2242530 A GB 2242530A
- Authority
- GB
- United Kingdom
- Prior art keywords
- seal
- pipeline
- pressure
- plug
- inner core
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
- G01M3/28—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
- G01M3/2884—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for welds
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/022—Test plugs for closing off the end of a pipe
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
- G01M3/28—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
- G01M3/2853—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipe joints or seals
Abstract
A device 1 for pressure testing the integrity of an internal weld joint 2 in the wall 3 of the pipeline comprises a frusto-conical sealing plug 6 at each end of a pressure introducing portion 4. Each plug 6 has a seal 8 attached to it. The seal 8 comprises an outer wall engaging portion 9 and an inner core portion 10. The outer portion 9 is formed from a resiliently deformable material having a Shore A hardness in the range 50 to 65 and the inner core portion 10 is formed from a less resiliently deformable material having a Shore A hardness in the range 85 to 90. The seals are urged against the pipe walls by thrust members 11 moving axially. <IMAGE>
Description
A Pressure Device
This invention relates to a device for introducing pressure into a device, and particularly, but not exclusively to a device for use in a length of pipeline.
Pipelines may be used to carry gas or oil and often the walls of the pipeline have to be able to withstand very substantial pressures. During the lifetime of a pipeline, it is often necessary to repair the walls of a pipeline (or to attach a fresh length) by welding the wall at an appropriate point to form a weld joint. Also, when it is required to attach a flange to an end of pipeline, the flange must be welded to the pipeline, by means of weld joints.
It is important that the integrity of such weld joints can be tested in order to ensure that the pipeline is capable of withstanding high pressures.
A known device for testing the integrity of such weld joints comprises two sealing portions attached to either end of a pressure introducing portion. The sealing portions are each in the form of a plug having a frustoconical shape, and having a cross-sectional shape which is substantially the same as that of the pipeline. The crosssectional shape of the pipeline is not always constant along the length of the pipeline. For example, towards the middle of a length of pipeline ovality can occur. That is, the cross-sectional shape of the pipeline tends to become oval, rather than circular. Also, chemicals contained in the oil or gas such as H2S can act on the walls of the pipeline such that irregularities are introduced into the surface of the walls.
In order to form a pressure-tight seal between each sealing portion and the walls of the pipeline it is therefore necessary to attach a seal to the surface of the the plug. The seal is made of a resiliently deformable material, and in use, when a pressure is applied to the pipeline, in ormer to test the integrity of a weld joint, the seal is forced into the space defined between the frusto-conical surface of the plug, and the walls of the pipeline, and thus forms a pressure-tight seal.
A seal thruster acts upon each seal in response to the pressure introduced in to the pipeline to ensure that the seals are acted upon by axial forces only. This ensures that a good seal is formed.
A disadvantage of this known device is that the seal, which must be resiliently deformable in order to form a pressure tight seal against the pipe wall, is extrudable.
As a result, the seal may be extruded through a small gap between the surface of the plug, and the wall of the pipe by the forces exerted upon it due to the high pressure introduced into the pipeline. This in turn, results in the seal being broken.
According to the invention there is provided apparatus for introducing pressure into a chamber, the chamber having a first end and a second end, and walls, the apparatus comprising: a pressure introducing portion having a first end and a second end; a first sealing portion for forming the first end of the chamber and attached to the first end of the pressure introducing portion and comprising:
a frusto-conical plug;
a seal attached to the surface of the plug;
and thrusting means attached to the pressure
introducing means for acting on the seal, characterised in that the seal comprises an outer wall engaging resiliently deformable portion, and an inner core portion which is substantially less resiliently deformable than the wall engaging portion.
By forming the seal with an inner core which is less resiliently deformable than the outer portion, the resulting composite seal is not extrudable through any small gap which may exist between the plug and the walls of the chamber. However, the presence of the outer resiliently deformable portion ensures that a pressure tight seal is formed between the sealing portion and the walls of the chamber, even if irregularities exist in the walls.
Preferably the cross-sectional shape of the plug is substantially circular. The apparatus may then be used in a pipeline of substantially circular cross-section. The apparatus may be used to test the weld joints of a flange attached to the end of the pipeline. The flange then forms the second end of the chamber. The apparatus must also be used as a high pressure pipe plug.
Preferably the apparatus further comprises a second sealing portion substantially the same as the first sealing portion, forming the second end of the chamber and attached to the second end of the pressure introducing portion.
Thus a pressure-tight cnamber may be defined by the first and second sealing portions, and the walls of the chamber.
The apparatus may then be used to test a welding joint at some point along the pipeline.
Preferably, the outer wall engaging portion and the inner core portion each comprise an elastomeric material.
Preferably, also the outer wall engaging portion has a
Shore A hardness of 50-65, and the inner core portion has
Shore A hardness of 85-90.
The invention will now be described by way of example only with reference to the accompanying drawings in which
Figure 1 is a schematic diagram of a device made in accordance with the invention.
Referring to figure 1, a pressure testing device 1 is to be used to test the integrity of an internal weld joint 2 in the wall 3 of a pipeline. The pipeline is of the type used to carry oil or gas, and must be able to withstand pressures of the order of 6000 psi. The diameter of such a pipeline may be anything from 2 inches to 36 inches. The device 1 comprises a pressure introducing portion 4 for applying a pressure to the weld joint 2 in order to test its integrity. Attached to each end of the pressure introducing portion 4 is a sealing portion 5.
Each sealing portion comprises a frusto-conical plug 6 which has a cross-sectional area which is approximately the same as that of the pipeline. However, due to irregularities in the wall 3, due to ovality, or attack by chemicals such as H2S, the plugs 6 may not always form an exact fit with the wall 3. As a result there will typically be a gap 7 of approximately 8-lOmm between the surface of the plug 6 and the wall 3. Attached to each plug 6, is a seal 8. Each seal 8 comprises an outer wall engaging portion 9 and an inner core portion 10. The outer portion 9 is formed from a resiliently deformable material having a Shore A hardness in the range 50-65 and the inner core portion 10 is formed from a less resiliently deformable material ha.ing a Shore A hardness in the range 85-90. Attached to the pressure introducing portion 4 are thrusting means 11, which are positioned adjacent the seals 8.
In use. pressure is applied to the chamber formed by the walls 3 and the seal portions 5 via pressure introducing portion 4. The pressure acts on the thrusting means 11, which in turn act upon the seals 8. so as to subject them to axial forces. The seal 8 is forced into the space between the surface of each of plugs 6 and the wall 3 so as to form a pressure tight seal around each of the plugs 6. Because the seal is formed from an inner less resiliently deformable core 10 to which is attached an outer resiliently deformable portion 9, it is not possible for the seal to be forced through the gaps 7.
The outer portion 9 is attached to the inner core 10 by means of an adhesive. In order to improve the adhesion between the core 10 and the outer portion 9, the outer portion extends to cover all exposed areas of the inner core 10.
Claims (7)
1. Apparatus (1) for introducing pressure into a chamber.
the chamber having a first end and a second end, and walls.
the apparatus comprising: a pressure introducing portion (4) having a first end and a second end; a sealing portion (5) for forming the first end of the chamber and attached to the first end of the pressure introducing portion (4) and comprising:
a frusto-conical plug (6);
a seal (8) attached to the surface of the plug (6);
and thrusting means (11) for acting on the seal (8), characterised in that the seal (8) comprises an outer wall engaging resiliently deformable portion (9) and an inner core portion (10) which is substantially less resiliently deformable than the wall engaging portion.
2. Apparatus as claimed in claim 1 further comprising a second sealing portion (4) substantially the same as the first sealing portion for forming the second end of the chamber and attached to the second end of the pressure introducing portion.
3. Apparatus according to any one of the preceding claims wherein the outer wall engaging portion (9) and the inner core portion (10) each comprise an elastomeric material.
4. Apparatus according to any one of the preceding claims wherein the outer wall engaging portion (9) has a Shore A hardness of 50-65.
5. Apparatus according to any of the preceding claims wherein the inner core portion (10) has a Shore A hardness of 85-90.
6. Apparatus according to any one of the preceding claims wherein the plug (4) has a circular cross-section.
7. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9006819A GB2242530B (en) | 1990-03-27 | 1990-03-27 | A pressure device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9006819A GB2242530B (en) | 1990-03-27 | 1990-03-27 | A pressure device |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9006819D0 GB9006819D0 (en) | 1990-05-23 |
| GB2242530A true GB2242530A (en) | 1991-10-02 |
| GB2242530B GB2242530B (en) | 1993-08-18 |
Family
ID=10673334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9006819A Expired - Lifetime GB2242530B (en) | 1990-03-27 | 1990-03-27 | A pressure device |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2242530B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4224419A1 (en) * | 1992-07-24 | 1994-01-27 | Deutsche Aerospace | Pipe seal for testing water-tightness of drinking water or waste pipes - has sealing unit containing two for more membranes which contact pipe wall when under pressure |
| WO1999054699A1 (en) * | 1998-04-17 | 1999-10-28 | Culloden Engineering Limited | Pipe testing apparatus |
| WO2002001174A1 (en) * | 2000-06-27 | 2002-01-03 | Horst Gotowik | Apparatus for testing or isolating a segment of pipe |
| US7628056B2 (en) * | 2006-03-22 | 2009-12-08 | Karl-Heinz Krah Gmbh | Internal pressure testing apparatus and method for pipe |
| CN103697284A (en) * | 2013-12-18 | 2014-04-02 | 天津绿清管道科技股份有限公司 | Pressure test device for pipe fittings |
| CN112113849A (en) * | 2020-09-08 | 2020-12-22 | 天津大学 | Method for applying initial defects of submarine pipeline |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1289969A (en) * | 1969-01-27 | 1972-09-20 |
-
1990
- 1990-03-27 GB GB9006819A patent/GB2242530B/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1289969A (en) * | 1969-01-27 | 1972-09-20 |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4224419A1 (en) * | 1992-07-24 | 1994-01-27 | Deutsche Aerospace | Pipe seal for testing water-tightness of drinking water or waste pipes - has sealing unit containing two for more membranes which contact pipe wall when under pressure |
| WO1999054699A1 (en) * | 1998-04-17 | 1999-10-28 | Culloden Engineering Limited | Pipe testing apparatus |
| AU757937B2 (en) * | 1998-04-17 | 2003-03-13 | Hedley Purvis Limited | Pipe testing apparatus |
| WO2002001174A1 (en) * | 2000-06-27 | 2002-01-03 | Horst Gotowik | Apparatus for testing or isolating a segment of pipe |
| GB2369871A (en) * | 2000-06-27 | 2002-06-12 | Horst Gotowik | Apparatus for testing or isolating a segment of pipe |
| US6601437B2 (en) | 2000-06-27 | 2003-08-05 | United Testing Corp. | Apparatus for testing or isolating a segment of pipe |
| US7628056B2 (en) * | 2006-03-22 | 2009-12-08 | Karl-Heinz Krah Gmbh | Internal pressure testing apparatus and method for pipe |
| CN103697284A (en) * | 2013-12-18 | 2014-04-02 | 天津绿清管道科技股份有限公司 | Pressure test device for pipe fittings |
| CN103697284B (en) * | 2013-12-18 | 2015-07-29 | 天津绿清管道科技股份有限公司 | A kind of pipe pressure test device |
| CN112113849A (en) * | 2020-09-08 | 2020-12-22 | 天津大学 | Method for applying initial defects of submarine pipeline |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9006819D0 (en) | 1990-05-23 |
| GB2242530B (en) | 1993-08-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Expiry date: 20100326 |