Polyurethane-sprayed polyethylene-wound thermal insulation pipeline joint

Abstract

The utility model relates to a polyurethane spraying polyethylene winding thermal insulation pipeline joint in the technical field of thermal insulation pipelines, which is characterized in that an epoxy zinc-rich primer anticorrosive coating, a polyurethane thermal insulation layer and a polyethylene outer protective layer are sequentially arranged on the outer side of a joint steel pipe, exposed steel pipe parts are arranged at the two ends of the joint steel pipe, and groove grooves are formed in the outer pipe walls of the exposed steel pipe parts; a nested welding mode is adopted between the outer diameter of the joint steel pipe and the working steel pipe of the heat preservation pipeline, and a circle of welding reinforcing ring is formed in the groove after welding; the two ends of the polyethylene outer protection layer extend out of a suspended sheath part, a plurality of grooves are formed in the outer side wall of the suspended sheath part, a plurality of hot melting reinforcing rings are formed in the grooves after the polyethylene sleeve is welded in an electric hot melting mode, a first heat shrinkage belt is further arranged on the outer side of the polyethylene sleeve, a glue injection hole is formed in the polyethylene sleeve, and a polyethylene welding plug and a second heat shrinkage belt are arranged on the glue injection hole. The pipeline joint can effectively avoid the problems of drip leakage in the thermal insulation pipeline and bursting and water seepage at the hot melting joint of the polyethylene outer protective layer, and the service life of the thermal insulation pipeline is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal insulation pipes, and in particular relates to a polyurethane sprayed polyethylene wound thermal insulation pipe joint. Background Art

[0002] Insulated pipes are also called thermal pipes. Polyurethane sprayed polyethylene wrapped insulated pipes are a common type of thermal pipes among insulated pipes. Their structure is generally composed of a polyurethane insulation layer sprayed on the outside of the working steel pipe and a wrapped polyethylene outer sheath.

[0003] Insulated pipes are usually directly laid underground or erected outdoors. During the construction of thermal pipes, the insulated pipes are connected one by one to form a long-distance thermal transmission pipeline. Pipe joints are required to connect the insulated pipes, especially at the bifurcation of the pipes. During the on-site construction of pipeline laying, in order to ensure the waterproof and anti-corrosion performance of the pipeline interface, an air tightness test is generally required after wrapping the polyethylene outer sheath and before filling the polyurethane insulation layer to ensure that the outer sheath is well sealed and leak-proof. In this way, during the subsequent operation of the pipeline, there will be no problems such as water ingress and moisture in the insulation layer, corrosion of the working steel pipe, etc., which is conducive to extending the service life of the thermal pipeline.

[0004] The existing polyurethane sprayed polyethylene wrapped thermal insulation pipe joints are directly welded to the working steel pipe mouth, and then the polyethylene outer sheath is hot-melted and wrapped around the interface by electric hot-melt, and then the air tightness test is performed, and then the polyurethane insulation layer is filled. After the construction, the welding joints of the working steel pipe are relatively weak and prone to dripping during operation; or the hot-melt connection of the polyethylene outer sheath bursts and leaks, so that the filled polyurethane insulation layer is also prone to cracks and peeling, which in turn affects the service life of the thermal insulation pipe. Therefore, it is necessary to design a safer and more reliable thermal insulation pipe joint. Utility Model Content

[0005] In view of the above situation, the utility model provides a polyurethane sprayed polyethylene wrapped thermal insulation pipe joint, which can better solve the technical problems existing in the prior art.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A polyurethane sprayed polyethylene wrapped thermal insulation pipe joint, comprising a joint steel pipe, used to connect the working steel pipe of the thermal insulation pipe, the outer side of the joint steel pipe is coated with a primer anti-corrosion layer, the outer side of the primer anti-corrosion layer is sprayed with a polyurethane thermal insulation layer, the outer side of the polyurethane thermal insulation layer is wrapped with a polyethylene outer sheath, both ends of the joint steel pipe are respectively provided with 15 to 20 cm exposed steel pipe parts, a circle of bevel grooves are annularly arranged on the outer pipe wall of the exposed steel pipe part at a position 3 to 5 cm away from the end of the joint steel pipe, the outer diameter of the joint steel pipe matches the inner diameter of the working steel pipe of the thermal insulation pipe, when the pipes are connected, A nested end welding method is adopted between the two, and a circle of welding reinforcement ring is formed in the groove groove after welding; the two ends of the polyethylene outer sheath respectively extend a 5-8 cm suspended sheath part, and a plurality of grooves are arranged in a ring on the outer wall of the suspended sheath part. When the pipeline is connected, the polyethylene outer sheath of the pipeline joint and the outer side of the polyethylene outer sheath of the insulation pipeline are electrothermally welded with a polyethylene sleeve, and a plurality of hot-melt reinforcement rings are formed in the plurality of grooves after welding. The polyethylene sleeve is provided with a glue injection hole for pouring polyurethane foam into the annular cavity inside the polyethylene sleeve.

[0008] Preferably, the primer anti-corrosion layer is a layer of epoxy zinc-rich primer coating sprayed on the outer surface of the joint steel pipe.

[0009] Preferably, the bevel groove is a circular groove with an isosceles trapezoidal cross-section; when the pipelines are connected, the outer wall of the joint steel pipe is slidably nested on the inner side of the working steel pipe, and the end of the working steel pipe of the insulation pipeline is aligned with the bevel groove for welding.

[0010] Preferably, the groove is a hook-retracting groove with a serrated cross-section; when the pipelines are connected, a polyethylene sleeve is wrapped between the polyethylene outer sheath of the pipeline joint and the polyethylene outer sheath of the insulation pipeline, and the three are hot-melt welded by electric hot-melt connection.

[0011] Preferably, a heat shrinkable tape is also sleeved on the outside of the welding ends at both ends of the polyethylene sleeve; a pluggable polyethylene welding plug is also provided on the glue injection hole, which is used to hot-melt plug the glue injection hole after glue injection, and the polyethylene welding plug is inserted into the glue injection hole and hot-melt welding is performed, and a heat shrinkable tape is also annularly sleeved on the outer periphery of the polyethylene sleeve at the position of the polyethylene welding plug.

[0012] The utility model also includes other components that enable it to be used normally, all of which are conventional means in the field. In addition, devices or components not limited in the utility model, such as: working steel pipes and polyethylene outer sheaths of the insulation pipes, as well as polyethylene sleeves, polyethylene welding plugs, heat shrinkable tapes, polyurethane foams, etc., all adopt the existing technologies in the field.

[0013] The beneficial effects of the utility model are as follows:

[0014] The polyurethane sprayed polyethylene wrapped insulated pipe joint provided by the utility model adopts a nested end welding method between the joint steel pipe and the working steel pipe of the insulated pipe, and a bevel groove is also provided at the weld, so that a welding reinforcement ring can be formed after welding. Compared with the direct butt welding method of the steel pipe end in the prior art, the connection strength and reliability are significantly improved, and the problem of dripping inside the pipe can be effectively avoided.

[0015] Furthermore, on the basis of the traditional electric hot-melt welding method, a plurality of hook-stop grooves are added at the welding point between the polyethylene outer sheath and the polyethylene sleeve of the polyurethane sprayed polyethylene wrapped insulated pipe joint and the polyethylene outer sheath of the insulated pipe. After hot-melt welding, the polyethylene sleeve can sink at the welding point to form a plurality of hot-melt reinforcement rings, and heat shrinkable belts are added at both ends of the polyethylene sleeve, its glue injection holes and the outside of the welding plug, which is beneficial to improving the air tightness and reliability of the polyethylene outer sheath, and can effectively avoid the bursting and water seepage at the hot-melt connection of the polyethylene outer sheath in the prior art, and can also effectively prevent the polyurethane insulation layer from cracking, peeling and other problems, thereby ensuring the service life of the insulated pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the thermal insulation pipe joint in the utility model.

[0017] Figure 2 The utility model is a schematic structural diagram of the thermal insulation pipe joint when connected to the thermal insulation pipe.

[0018] Figure 3 for Figure 2 Schematic diagram of the partially enlarged structure of part A in the middle. DETAILED DESCRIPTION

[0019] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments.

[0020] Example

[0021] like Figure 1-3 As shown, a polyurethane sprayed polyethylene wrapped insulated pipe joint includes a joint steel pipe 1, which is used to connect the working steel pipe 16 of the insulated pipe. The outer side of the joint steel pipe is coated with an epoxy zinc-rich primer anti-corrosion layer 2, the outer side of the primer anti-corrosion layer is sprayed with a polyurethane insulation layer 3, and the outer side of the polyurethane insulation layer is wrapped with a polyethylene outer protective layer 4.

[0022] Both ends of the joint steel pipe are respectively provided with a 15-20 cm exposed steel pipe part 5, the outer diameter of the joint steel pipe is equal to the inner diameter of the working steel pipe of the insulation pipe, when the pipes are connected, the outer wall of the joint steel pipe is slidably sleeved on the inner side of the working steel pipe, and a nested end connection method is adopted. A circle of bevel groove 6 is annularly provided on the outer pipe wall of the exposed steel pipe part at a position 3-5 cm away from the end of the joint steel pipe. When the pipes are connected, the end of the working steel pipe of the insulation pipe is aligned with the bevel groove for welding, and a circle of welding reinforcement ring 7 is formed in the bevel groove after welding.

[0023] Both ends of the polyethylene outer sheath are integrally extended with a 5-8 cm suspended sheath portion 8, and a plurality of grooves 9 are annularly provided on the outer wall of the suspended sheath portion. When the pipelines are connected, a polyethylene sleeve 10 is wrapped between the polyethylene outer sheath of the pipeline joint and the polyethylene outer sheath of the insulation pipeline, and the three are hot-melt welded by electric hot-melt connection. After welding, a plurality of hot-melt reinforcement rings 11 are formed in the plurality of grooves.

[0024] In addition, a heat shrinkable belt 12 is hot-melt-sleeved on the outside of the welding ends at both ends of the polyethylene sleeve. A glue injection hole 13 is opened on the polyethylene sleeve for pouring polyurethane foam into the annular cavity inside the polyethylene sleeve. A pluggable polyethylene welding plug 14 is provided on the glue injection hole. After the glue injection is completed, the polyethylene welding plug is inserted into the glue injection hole for hot-melt welding. In addition, a heat shrinkable belt 15 is annularly sleeved on the outer periphery of the polyethylene sleeve at the position of the polyethylene welding plug.

[0025] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to ordinary technicians in this technical field. Any technical deformation made within the spirit and principles of the present invention falls within the protection scope of the present invention.

Claims

1. A polyurethane sprayed polyethylene wrapped thermal insulation pipe joint, comprising a joint steel pipe, used to connect the working steel pipe of the thermal insulation pipe, characterized in that: The outer side of the joint steel pipe is coated with a primer anti-corrosion layer, the outer side of the primer anti-corrosion layer is sprayed with a polyurethane insulation layer, and the outer side of the polyurethane insulation layer is wrapped with a polyethylene outer sheath. Both ends of the joint steel pipe are respectively provided with 15 to 20 cm exposed steel pipe parts, and a circle of bevel grooves are annularly arranged on the outer pipe wall of the exposed steel pipe part at a position 3 to 5 cm away from the end of the joint steel pipe. The outer diameter of the joint steel pipe matches the inner diameter of the working steel pipe of the insulation pipeline. When the pipelines are connected, a nested end welding method is adopted between the two. After welding A circle of welding reinforcement ring is formed in the groove groove; 5 to 8 cm suspended sheath parts are integrally extended from both ends of the polyethylene outer sheath, and multiple grooves are arranged in a ring on the outer side wall of the suspended sheath part. When the pipelines are connected, the polyethylene outer sheath of the pipeline joint and the outer side of the polyethylene outer sheath of the insulation pipeline are electrothermally welded with a polyethylene sleeve, and multiple hot-melt reinforcement rings are formed in the multiple grooves after welding. Glue injection holes are arranged on the polyethylene sleeve for pouring polyurethane foam into the annular cavity inside the polyethylene sleeve.

2. The polyurethane sprayed polyethylene wrapped thermal insulation pipe joint according to claim 1, characterized in that: The primer anti-corrosion layer is a layer of epoxy zinc-rich primer coating sprayed on the outer surface of the joint steel pipe.

3. The polyurethane sprayed polyethylene wrapped thermal insulation pipe joint according to claim 1, characterized in that: The groove is a circular groove with an isosceles trapezoidal cross section.

4. The polyurethane sprayed polyethylene wrapped thermal insulation pipe joint according to claim 1, characterized in that: The groove is a hook-return stop groove with a sawtooth-shaped cross section.

5. The polyurethane sprayed polyethylene wrapped thermal insulation pipe joint according to claim 4, characterized in that: The outer sides of the welding ends at both ends of the polyethylene sleeve are also sleeved with a heat shrinkable belt.

6. The polyurethane sprayed polyethylene wrapped thermal insulation pipe joint according to claim 5, characterized in that: The glue injection hole is also provided with a pluggable polyethylene welding plug for hot-melting and plugging the glue injection hole after glue injection, and a second heat shrinkable belt is annularly sleeved on the outer periphery of the polyethylene sleeve at the position of the polyethylene welding plug.

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