CN112454915A - Butt welding method for polyethylene-coated pipelines - Google Patents
Butt welding method for polyethylene-coated pipelines Download PDFInfo
- Publication number
- CN112454915A CN112454915A CN201910846533.4A CN201910846533A CN112454915A CN 112454915 A CN112454915 A CN 112454915A CN 201910846533 A CN201910846533 A CN 201910846533A CN 112454915 A CN112454915 A CN 112454915A
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- CN
- China
- Prior art keywords
- cutting
- stripped
- butt welding
- polyethylene
- clad
- 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.)
- Withdrawn
Links
- 238000003466 welding Methods 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 title claims abstract description 28
- 239000004698 Polyethylene Substances 0.000 title claims abstract description 23
- 229920000573 polyethylene Polymers 0.000 title claims abstract description 23
- -1 polyethylene Polymers 0.000 title claims abstract description 21
- 238000005520 cutting process Methods 0.000 claims abstract description 37
- 239000011247 coating layer Substances 0.000 claims abstract description 36
- 239000002390 adhesive tape Substances 0.000 claims abstract description 14
- 239000011248 coating agent Substances 0.000 claims abstract description 14
- 238000000576 coating method Methods 0.000 claims abstract description 14
- 238000004804 winding Methods 0.000 claims abstract description 7
- 238000002844 melting Methods 0.000 claims abstract description 6
- 230000008018 melting Effects 0.000 claims abstract description 5
- 239000010410 layer Substances 0.000 claims description 29
- 238000005253 cladding Methods 0.000 claims description 12
- 239000000835 fiber Substances 0.000 claims description 4
- 238000010276 construction Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000011241 protective layer Substances 0.000 description 4
- 239000004743 Polypropylene Substances 0.000 description 3
- 238000003801 milling Methods 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/02—Preparation of the material, in the area to be joined, prior to joining or welding
- B29C66/022—Mechanical pre-treatments, e.g. reshaping
- B29C66/0224—Mechanical pre-treatments, e.g. reshaping with removal of material
- B29C66/02241—Cutting, e.g. by using waterjets, or sawing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/03—After-treatments in the joint area
- B29C66/038—Covering the joint by a coating material
- B29C66/0384—Covering the joint by a coating material the coating material being in tape, strip or band form
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5221—Joining tubular articles for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2023/00—Tubular articles
- B29L2023/22—Tubes or pipes, i.e. rigid
Abstract
The invention discloses a butt welding method for polyethylene-coated pipelines. The butt welding method of the polyethylene-clad pipeline comprises the following steps: s1: cutting and stripping the coating layer at the connecting end part of the two pipelines to be welded by using a stripping tool; s2: butt welding the connecting end parts of the two pipelines by using a hot melting welding device; s3: inspecting the welding quality and ensuring that the welding quality meets the specified standard; s4: coating the stripped coating layers on the corresponding working pipelines respectively; s5: and winding an adhesive tape on the stripped coating layer, and fixing the stripped coating layer on the working pipeline. The coating layer is wrapped on the welded working pipeline, so that the working pipeline can be prevented from being exposed, and the pipeline surface at the welding position is prevented from being damaged. Meanwhile, the original coating layer is used for wrapping, so that the cost can be effectively saved.
Description
Technical Field
The invention relates to a butt welding method for polyethylene-coated pipelines.
Background
In the practical application process, Polyethylene (PE) pipes need to be rolled and dragged in the storage, transportation and construction processes, particularly in trenchless construction and old pipeline repair, the welded pipelines of dozens of meters or even hundreds of meters need to be dragged into old pipelines by a tractor, and in the whole process, the pipeline surfaces are required to be hardly scratched, and the scratches become crack sources for bearing slow crack growth of internal pressure pipelines, so that the service life of a pipeline system and the safety and stability of a pipe network are influenced. Therefore, in the construction process, an operator is required not to drag the pipeline on the ground, the scratch does not exceed 10% of the wall thickness of the pipeline, and the penetration construction does not exceed 5% of the wall thickness of the pipeline, so that the management and training cost is increased, and meanwhile, a lot of inconvenience is brought. The polyethylene coated pipeline is a polyethylene pipeline with a protective layer on the outer wall, the protective layer is made of polypropylene (PP) materials, on the basis of not influencing the performance of an internal working pipeline, the high hardness (reaching more than 1.5 times of PE materials) of the outer PP materials and the high impact resistance (reaching more than 3 times of PE materials) of the working pipeline are protected, the safety of the pipeline can be improved in the construction process, and the damage to the pipeline caused by artificial and environmental factors is avoided to the maximum extent. When the cladding pipeline is welded, a part of the outer protective layer needs to be stripped, and the welded crater is not protected by the protective layer and is in an exposed state and is easily scratched.
Disclosure of Invention
The invention aims to overcome the defect that a polyethylene-coated pipeline in the prior art is easy to damage after being welded, and provides a butt welding method for the polyethylene-coated pipeline.
The invention solves the technical problems through the following technical scheme:
the butt welding method for the polyethylene-coated pipeline is characterized by comprising the following steps of:
s1: cutting and stripping the coating layer at the connecting end part of the two pipelines to be welded by using a stripping tool;
s2: butt welding the connecting end parts of the two pipelines by using a hot melting welding device;
s3: inspecting the welding quality and ensuring that the welding quality meets the specified standard;
s4: coating the stripped coating layers on the corresponding working pipelines respectively;
s5: and winding an adhesive tape on the stripped coating layer, and fixing the stripped coating layer on the working pipeline.
Preferably, the method for cutting the cladding layer in step S1 includes:
s11: determining the cutting length of the cladding layer to be stripped along the axial direction;
s12: installing the stripping tool to the cutting position of the pipeline, and circumferentially and circularly cutting the cladding layer to be stripped;
s13: and cutting the coating layer to be stripped along the axial direction from the end face of the pipeline to the cutting position.
Preferably, the coating layer to be stripped in step S13 is completely cut through in the axial direction without damaging the surface of the working pipe.
Preferably, in step S11, the stripping tool cuts multiple times in the circumferential direction and gradually increases the cutting depth, the cutting depth is greater than the minimum thickness of the clad layer and less than the maximum thickness of the clad layer, and the circumferential cut-through length of the clad layer to be stripped does not exceed 20%.
Preferably, the stripping tool comprises an annular cutter and a linear cutter, the annular cutter can rotate around the pipeline and cut the coating layer to be stripped, and the linear cutter can cut the coating layer to be stripped along the axial direction.
Preferably, the coating is stripped in a radial direction.
Preferably, before welding the two pipes in step S2, the end faces of the two pipes need to be cleaned.
Preferably, the winding range of the adhesive tape in the step S1 exceeds the end face of the coating layer to be peeled by 3cm or more.
Preferably, the adhesive tape in step S1 is a fiber adhesive tape.
On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.
The positive progress effects of the invention are as follows: through wrapping up the coating on accomplishing welded working pipeline, can avoid working pipeline to be in naked state, improve welding position's surface texture intensity to avoid welding position's pipeline surface to produce the damage. Meanwhile, the original coating layer is utilized to wrap, so that the material is recycled, and the cost can be effectively saved.
Drawings
Fig. 1 is a schematic sectional view showing a structure of a pipe to be welded in a preferred embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a pipe to be welded with a coating layer removed from the joint end portion in accordance with a preferred embodiment of the present invention.
Fig. 3 is a schematic cross-sectional view of two pipes to be welded according to a preferred embodiment of the present invention.
Fig. 4 is a schematic cross-sectional view of two pipes to be welded wound with an adhesive tape in a preferred embodiment of the present invention.
Description of reference numerals:
working pipe 10
Coating 20
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
Fig. 1-4 illustrate a method of butt welding polyethylene clad pipe, which includes a work pipe 10 and a cladding layer 20 clad to the surface thereof. The butt welding method of the polyethylene-coated pipeline comprises the following steps:
s1: cutting and stripping the coating layer 20 at the connecting end position of the two pipelines to be welded by using a stripping tool;
s2: butt welding the connecting end parts of the two pipelines by using a hot melting welding device;
s3: inspecting the welding quality and ensuring that the welding quality meets the specified standard;
s4: coating the stripped coating layers 20 on the corresponding working pipelines 10 respectively;
s5: the stripped coating layer 20 is fixed to the working pipe 10 by winding an adhesive tape 30 around the stripped coating layer 20.
By wrapping the coating layer 20 on the welded working pipeline 10, the working pipeline 10 can be prevented from being exposed, the surface structural strength of the welding position can be improved, and the pipeline surface of the welding position can be prevented from being damaged. In order to ensure that the welding quality meets the use requirements, the hot-melting welding needs to be carried out according to the process rules HG/T4281-2011, and the welding quality needs to be evaluated in comparison with the industry standards HG/T4280-2011 after the welding is finished.
Since the cut coating 20 also needs to be reused (recoiled onto the service pipe 10), it is desirable to avoid compromising the integrity of the coating 20 during the cutting process. In this embodiment, the method for cutting the cladding layer 20 in step S1 includes:
s11: determining the cutting length of the cladding layer 20 to be stripped along the axial direction;
s12: installing a stripping tool at the cutting position of the pipeline, and cutting the coating layer 20 to be stripped circumferentially;
s13: the clad layer 20 to be stripped is cut in the axial direction from the end face of the pipe to the cutting position.
Cutting in the above manner is beneficial to protecting the integrity of the coating layer 20, and at the same time, is easy to cut and peel, and can improve the efficiency of the whole operation process.
In this embodiment, the coating layer 20 to be peeled off in step S13 is completely cut through in the axial direction without damaging the surface of the work pipe 10. The complete cutting through of the coating 20 in the axial direction is to facilitate the stripping of the coating 20.
The manner of circumferentially cutting the cladding layer 20 is: in step S11, the stripping tool cuts and gradually increases the cutting depth along the circumferential direction, the cutting depth is greater than the minimum thickness of the clad layer 20 and less than the maximum thickness of the clad layer 20, and the circumferential cut-through length of the clad layer 20 to be stripped does not exceed 20%.
The thickness of the coating 20 actually applied to the working pipe 10 is not exactly the same but is within a certain range.
As shown in the above table, the minimum thickness of the coating layer 20 on the pipe having an outer diameter of 110mm is 0.9mm, and the maximum thickness is 1.5 mm. Therefore, when the coating layer 20 is cut in the circumferential direction, a gradually deeper cutting is required to ensure that the thinnest coating layer 20 can be cut through, and at the same time, the thickest coating layer 20 is not cut, which results in serious damage to the surface of the working pipe 10. In determining the cut-through length, it is preferable that the circumferential cut-through length is not more than 20% of the circumference.
In order to facilitate cutting of the clad layer 20, the peeling tool includes a circular cutter which rotates around the pipe and cuts the clad layer 20 to be peeled, and a linear cutter which cuts the clad layer 20 to be peeled in an axial direction. The annular cutter can cut a circular cut around the pipeline and can ensure that the cut position coincides with the previous position every time the pipe is deepened. The straight line cutter facilitates cutting the coating 20 in the axial direction while achieving the function of completely cutting through the coating 20.
In order to reduce cracking of the clad layer 20 when the clad layer 20 is peeled off, the clad layer 20 is peeled off in the radial direction.
In order to improve the quality of butt welding of two pipelines, a milling cutter is generally used for milling a welding surface before welding, and then a hot melting welding device is used for welding. The milling cutter is used for cleaning the welding surface, a large amount of static electricity is generated, dust in the air is adsorbed, and the welding quality is influenced.
In order to ensure that the coated pipe craters do not expose the working pipe 10, the winding range of the adhesive tape 30 in step S1 exceeds the end surface of the stripped coating layer 20 by more than 3 cm.
In step S1, the tape 30 is a fiber tape. The fiber adhesive tape has extremely strong breaking strength, excellent wear resistance and moisture resistance, and can ensure that the stripped coating layer 20 cannot be separated from the working pipeline 10 for a long time, thereby improving the safety and reliability.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.
Claims (9)
1. The butt welding method for the polyethylene-coated pipeline comprises the following steps of:
s1: cutting and stripping the coating layer at the connecting end part of the two pipelines to be welded by using a stripping tool;
s2: butt welding the connecting end parts of the two pipelines by using a hot melting welding device;
s3: inspecting the welding quality and ensuring that the welding quality meets the specified standard;
s4: coating the stripped coating layers on the corresponding working pipelines respectively;
s5: and winding an adhesive tape on the stripped coating layer, and fixing the stripped coating layer on the working pipeline.
2. The butt welding method for polyethylene clad pipes as claimed in claim 1, wherein the method for cutting the clad layer in step S1 is:
s11: determining the cutting length of the cladding layer to be stripped along the axial direction;
s12: installing the stripping tool to the cutting position of the pipeline, and circumferentially and circularly cutting the cladding layer to be stripped;
s13: and cutting the coating layer to be stripped along the axial direction from the end face of the pipeline to the cutting position.
3. The butt welding method for polyethylene clad pipes as claimed in claim 2, wherein the cladding to be stripped in step S13 is completely cut through in the axial direction without damaging the surface of the working pipe.
4. The polyethylene clad pipe butt welding method of claim 3, wherein in step S11, the peeling tool cuts multiple times and gradually increases the cutting depth along the circumferential direction, the cutting depth is larger than the minimum thickness of the clad layer and smaller than the maximum thickness of the clad layer, and the circumferential cut-through length of the clad layer to be peeled is not more than 20%.
5. The butt welding method for polyethylene clad pipes as claimed in claim 4, wherein said peeling tool comprises a circular cutter capable of rotating around said pipe and cutting said clad layer to be peeled, and a linear cutter capable of cutting said clad layer to be peeled in an axial direction.
6. The method of butt welding polyethylene clad pipes as claimed in claim 4, wherein the cladding is peeled off in a radial direction.
7. The method of claim 1, wherein the end surfaces of the two pipes are cleaned before welding the two pipes in step S2.
8. The butt welding method for polyethylene clad pipes as claimed in claim 1, wherein the winding range of the adhesive tape in step S1 exceeds the end surface of the clad layer to be peeled by more than 3 cm.
9. The butt welding method for polyethylene clad pipes as claimed in claim 1, wherein the adhesive tape in step S1 is a fiber adhesive tape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910846533.4A CN112454915A (en) | 2019-09-09 | 2019-09-09 | Butt welding method for polyethylene-coated pipelines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910846533.4A CN112454915A (en) | 2019-09-09 | 2019-09-09 | Butt welding method for polyethylene-coated pipelines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112454915A true CN112454915A (en) | 2021-03-09 |
Family
ID=74807311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910846533.4A Withdrawn CN112454915A (en) | 2019-09-09 | 2019-09-09 | Butt welding method for polyethylene-coated pipelines |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112454915A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114571375A (en) * | 2022-04-11 | 2022-06-03 | 北京工商大学 | Micro abrasive gas jet cutting system and cutting method thereof |
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| JP2003305786A (en) * | 2002-04-15 | 2003-10-28 | Kubota Corp | Outer layer-coated polyolefin pipe |
| JP2006292111A (en) * | 2005-04-13 | 2006-10-26 | Buyou Gas Kk | Connecting method of synthetic resin pipe |
| JP2011179626A (en) * | 2010-03-03 | 2011-09-15 | Furukawa Electric Co Ltd:The | Resin pipe, manufacturing method and connecting method of the same, and resin tape |
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| CN109473944A (en) * | 2018-03-09 | 2019-03-15 | 东阳市光明电力建设有限公司 | A kind of cable connection structure and connection method convenient for detection |
| CN110131511A (en) * | 2019-05-17 | 2019-08-16 | 武汉海威船舶与海洋工程科技有限公司 | RTP tube electric smelting heats constant size connection structure and attaching method thereof |
-
2019
- 2019-09-09 CN CN201910846533.4A patent/CN112454915A/en not_active Withdrawn
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003207088A (en) * | 2002-01-11 | 2003-07-25 | Mesco Inc | Connecting method and structure for plastic pipe |
| JP2003305786A (en) * | 2002-04-15 | 2003-10-28 | Kubota Corp | Outer layer-coated polyolefin pipe |
| JP2006292111A (en) * | 2005-04-13 | 2006-10-26 | Buyou Gas Kk | Connecting method of synthetic resin pipe |
| JP2011179626A (en) * | 2010-03-03 | 2011-09-15 | Furukawa Electric Co Ltd:The | Resin pipe, manufacturing method and connecting method of the same, and resin tape |
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| CN114571375A (en) * | 2022-04-11 | 2022-06-03 | 北京工商大学 | Micro abrasive gas jet cutting system and cutting method thereof |
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