Nodular cast iron prefabricated thermal insulation pipe with anti-cracking performance

Abstract

The utility model relates to a nodular cast iron prefabricated thermal insulation pipe with anti-cracking performance in the field of thermal insulation pipe production, which comprises a working pipe, and a thermal insulation layer, an anti-cracking layer and an outer protective layer which are sequentially arranged on the outer side of the working pipe from inside to outside, the heat preservation layer is a hard polyurethane foam plastic layer coated on the outer side of the nodular cast iron pipe in a spraying mode, the anti-crack layer is a warp knitting glass fiber gridding cloth wrapping layer wound on the outer side of the polyurethane foam plastic layer, and the outer protection layer is a polyethylene winding layer spirally wound on the outer side of the glass fiber gridding cloth layer. And the glass fiber gridding cloth wrapping layer, the polyurethane foam layer and the polyethylene winding layer are glued and bonded together through an epoxy resin adhesive. According to the nodular cast iron prefabricated heat preservation pipe with the anti-cracking performance, the anti-cracking performance, corrosion resistance, pressure resistance, tensile strength and other performance of the heat preservation pipe can be effectively improved, and the service life of the heat preservation pipe is prolonged.

Description

Technical Field

[0001] The utility model belongs to the field of thermal insulation pipe production, and specifically relates to a ductile iron prefabricated thermal insulation pipe with anti-cracking performance. Background Art

[0002] Insulated pipes, also known as thermal pipes, are generally composed of steel pipes and the insulation layer wrapped around their outer sides. The insulation layer of existing insulated pipes is mostly a polyurethane foam layer. Since insulated pipes are usually laid directly underground or installed outdoors, wind, sun, rain, moisture, and corrosion will accelerate the aging of the steel pipes and the insulation layer. In particular, the polyurethane foam insulation layer is prone to cracking after aging, which in turn affects the insulation effect of the insulated pipe. In addition, the corrosion resistance, pressure resistance, and tensile strength of the existing insulated steel pipes are not ideal, which will seriously shorten the service life of the insulated pipes. Therefore, how to improve the crack resistance of the insulated pipes and increase the service life of the insulated pipes has always been a technical problem that the thermal pipe industry has been committed to solving. Utility Model Content

[0003] In view of the above situation, the utility model provides a ductile iron prefabricated insulated pipe with crack resistance, which can effectively improve the crack resistance, corrosion resistance, pressure resistance and tensile strength of the insulation pipe, and extend the service life of the insulation pipe.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A ductile iron prefabricated insulated pipe with anti-cracking performance comprises a working pipe and an insulation layer, an anti-cracking layer and an outer protective layer arranged on the outside of the working pipe in sequence from the inside to the outside, wherein the working pipe is a ductile iron pipe, the insulation layer is a polyurethane foam layer sprayed and coated on the outside of the ductile iron pipe, the anti-cracking layer is a glass fiber mesh cloth wrapping layer wrapped around the outside of the polyurethane foam layer, and the outer protective layer is a polyethylene wrapping layer wrapped around the outside of the glass fiber mesh cloth layer.

[0006] Furthermore, the ductile iron pipe is preferably a K9 grade ductile iron pipe, which has the characteristics of high wall thickness and high pressure bearing capacity.

[0007] Furthermore, the polyurethane foam layer is a hard polyurethane foam plastic layer, which has the characteristics of porosity, low relative density and high specific strength.

[0008] Furthermore, the glass fiber mesh cloth used in the glass fiber mesh cloth wrapping layer is a warp knitted glass fiber mesh cloth formed by bundling and overlapping glass fiber warp yarns and glass fiber weft yarns through warp knitted chemical fiber network yarns. It has the characteristics of high crack resistance, small elongation, good bonding with the inner insulation layer and the outer protective layer, and is not easy to peel off.

[0009] Furthermore, the polyethylene winding layer is fully and tightly wrapped around the outer side of the glass fiber mesh cloth layer by means of a heating, extruding and spiral winding molding method, thereby improving the corrosion resistance of the thermal insulation pipe.

[0010] Furthermore, the glass fiber mesh cloth wrapping layer, the polyurethane foam layer and the polyethylene winding layer are all bonded together by epoxy resin adhesive, ensuring the firmness and reliability of the connection between the polyurethane foam layer and the glass fiber mesh cloth wrapping layer and between the glass fiber mesh cloth wrapping layer and the polyethylene winding layer.

[0011] Furthermore, both ends of the working pipe are provided with exposed end portions of 150±10 mm, which is convenient for on-site welding between the butt ends of two sections of working pipes when laying the insulation pipe, and the exposed end portions need to be patched after welding.

[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: K9 grade ductile iron pipe, rigid polyurethane foam plastic, warp knitted glass fiber mesh cloth, polyethylene winding layer, etc., all adopt the existing technology in the field.

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

[0014] The utility model provides a ductile iron prefabricated insulated pipe with anti-cracking performance, which effectively improves the anti-cracking performance of the insulation pipe by adding a protective mesh layer on the outside of the polyurethane insulation layer and wrapping a polyethylene protective layer around the outer layer; at the same time, the inner working pipeline adopts a ductile iron pipe, which has significantly improved corrosion resistance, pressure resistance and tensile strength compared to ordinary steel pipes commonly used in the prior art; this is conducive to increasing the service life of the insulation pipe, extending the maintenance and replacement cycle of the insulation pipe, reducing the labor intensity of pipeline maintenance personnel, and saving the purchase cost and use cost of the thermal pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the ductile iron prefabricated insulation pipe in the embodiment.

[0016] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the ductile iron prefabricated insulation pipe. DETAILED DESCRIPTION

[0017] 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.

[0018] Example 1

[0019] like Figure 1-2As shown, a ductile iron prefabricated insulation pipe with anti-cracking performance includes a working pipe 1 and an insulation layer 2, an anti-cracking layer 3 and an outer protective layer 4 arranged on the outside of the working pipe in sequence from the inside to the outside.

[0020] The working pipe 1 is a K9 grade ductile iron pipe, which has the material properties of both cast iron and steel, has strong corrosion resistance, high mechanical strength, good ductility and good sealing effect.

[0021] The insulation layer 2 is a hard polyurethane foam plastic layer sprayed and coated on the outside of the ductile iron pipe, and has the advantages of porosity, low relative density and high specific strength.

[0022] The anti-cracking layer 3 is a layer of warp-knitted glass fiber mesh cloth formed by bundling and overlapping glass fiber warp yarns and glass fiber weft yarns wrapped around the outside of the polyurethane foam layer through warp-knitted chemical fiber network yarns. It has excellent crack resistance and good bonding with the inner polyurethane foam plastic layer and the polyethylene winding layer. It can effectively improve the anti-cracking performance of the insulation layer 2 and solve the problem of aging and cracking of the insulation layer 2.

[0023] The outer protective layer 4 is a polyethylene winding layer that is fully enclosed and spirally wrapped around the outside of the glass fiber mesh cloth layer by heating and extrusion molding. It helps to improve the waterproof, moisture-proof, corrosion-resistant and wear-resistant properties of the insulated pipe, and also protects the inner insulation layer 2.

[0024] The glass fiber mesh cloth wrapping layer is firmly bonded to the polyurethane foam layer and the polyethylene winding layer by means of an epoxy resin adhesive, thereby improving the bonding strength between the various layer structures of the thermal insulation pipe.

[0025] Both ends of the working pipe 1 are circumferentially cut to leave exposed end portions 5 of 150±10 mm, which is convenient for on-site welding between the butt ends of two sections of working pipes 1 when laying the insulated pipeline, and the exposed end portions 5 need to be patched after welding, that is, the outer sides of the butt joints are supplemented on-site with an insulation layer 2, an anti-cracking layer 3 and an outer protective layer 4 in sequence, to ensure the insulation, corrosion resistance and anti-cracking performance of the interface, which is beneficial to extending the service life of the insulated pipeline.

[0026] 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 ductile iron prefabricated insulation pipe with crack resistance, characterized in that: It includes a working pipe and an insulation layer, an anti-cracking layer and an outer protective layer arranged on the outside of the working pipe in sequence from the inside to the outside. The working pipe is a ductile iron pipe, the insulation layer is a polyurethane foam layer sprayed and coated on the outside of the ductile iron pipe, the anti-cracking layer is a glass fiber mesh cloth wrapping layer wrapped around the outside of the polyurethane foam layer, and the outer protective layer is a polyethylene wrapping layer wrapped around the outside of the glass fiber mesh cloth layer.

2. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: The ductile iron pipe is a K9 grade ductile iron pipe.

3. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: The polyurethane foam layer is a hard polyurethane foam plastic layer.

4. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: The glass fiber mesh cloth used in the glass fiber mesh cloth wrapping layer is a warp knitted glass fiber mesh cloth formed by bundling and overlapping glass fiber warp yarns and glass fiber weft yarns through warp knitted chemical fiber network yarns.

5. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: The polyethylene winding layer is spirally wound around the outer side of the glass fiber mesh cloth layer.

6. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: The glass fiber mesh cloth wrapping layer, the polyurethane foam layer and the polyethylene winding layer are all bonded together by epoxy resin adhesive.

7. The ductile iron prefabricated insulation pipe with crack resistance according to claim 1 is characterized in that: Both ends of the working tube are provided with exposed end sections.

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