CN215334973U - Cast iron composite pipe - Google Patents

Abstract

The utility model discloses a cast iron composite pipe, which is used for solving the problem that the manufacturing process of the existing cast iron pipe lining composite layer is complex. The cast iron pipe comprises a cast iron pipe, wherein a tubular lining layer is fixed in the cast iron pipe through cement mortar. And flanges for coating the cement mortar layer are arranged at the pipe orifices at the two ends of the tubular inner liner. The inner liner is bonded by cement mortar, the flatness of the inner surface of the cast iron pipe has no special requirement, the process step of polishing the inner wall of the cast iron pipe is saved, the cost is reduced, and the method is suitable for the inner liner made of plastics, stainless steel or copper materials.

Description

Cast iron composite pipe

Technical Field

The utility model relates to a cast iron pipe technical field, concretely relates to cast iron composite pipe.

Background

Cast iron pipe is a main pipeline used in the fields of urban water supply and water delivery and chemical industry, and there are three main technologies for corrosion prevention of cast iron pipe: the first technique is that the inside and outside of the cast iron pipe are coated with paint to form an anticorrosive coating. And secondly, adopting a cement mortar lining or an epoxy resin, epoxy ceramic and polyurethane coating in the cast iron pipe as an anticorrosion mode of the pipeline. And thirdly, adopting an epoxy resin coating liner in the cast iron pipe.

For example, chinese patent CN109210286A discloses a method for manufacturing a plastic-coated and plastic-lined metal composite pipe, which comprises the steps of manufacturing a plastic composite pipe, polishing the inner wall of the metal pipe, performing sand blasting, shot blasting or shot blasting treatment, drawing the plastic composite pipe into the treated metal pipe, sealing and inflating the two ends of the plastic composite pipe, performing heating treatment, spraying or coating the outer surface of the metal pipe, cooling, adhering the metal pipe and the plastic composite pipe, and achieving the purpose of simultaneously performing the outer spraying or coating and the inner lining on line. The corrosion prevention process of the structure is extremely complex, high in cost and complex in process.

SUMMERY OF THE UTILITY MODEL

In order to solve the defects of the prior art, the utility model provides a cast iron composite pipe which is used for solving the problem that the manufacturing process of the existing cast iron pipe lining composite layer is complex.

The technical scheme adopted by the utility model for solving the technical problems is as follows:

the cast iron composite pipe comprises a cast iron pipe, wherein a tubular lining layer is fixed in the cast iron pipe through cement mortar.

Furthermore, the cast iron pipe is a socket type nodular cast iron pipe.

Further, an outer anticorrosive layer is provided on the outer surface of the cast iron pipe.

Furthermore, flanges for coating the cement mortar layer are arranged at pipe orifices at two ends of the tubular inner liner layer.

Further, the tubular lining layer is one of a PP-R pipe, a PVC-U pipe, a stainless steel pipe or a copper pipe.

Further, the thickness of the cement mortar is between 1 cm and 2 cm.

Further, the cast iron pipe and the tubular inner lining layer are concentrically arranged.

Further, the cast iron pipe and the tubular inner lining layer are eccentrically arranged.

The utility model has the beneficial effects that:

the utility model bonds the lining plastic layer by cement mortar, has no special requirement on the flatness of the inner surface of the cast iron pipe, saves the process step of polishing the inner wall of the cast iron pipe and reduces the cost.

The inner wall of the plastic pipe has high smoothness, good corrosion resistance, high water delivery efficiency and long service life, and cement mortar is used as a binder and a filler, is safe and nontoxic and belongs to a green material.

The cast iron pipe and the plastic pipe are integrally cemented by cement mortar, the cast iron pipe matrix is not required to be heated, hot melt adhesive is not used, the cast iron pipe keeps good mechanical performance, the corrosion resistance and the service life of the pipeline are greatly improved by lining the plastic pipe, and the manufacturing cost is reduced.

The technology can also be used as an inner liner layer through a copper pipe and a stainless steel pipe, and the requirement of the special field on the pipe is met.

Drawings

Fig. 1 is a cross-sectional view of a cast iron composite pipe.

Fig. 2 is a plug-in connection diagram of the cast iron composite pipe.

In the figure:

10 cast iron pipe, 11 outer anticorrosive layer;

20, cement mortar;

30 plastic pipe and 31 flanging;

40 rubber seal ring.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

In this embodiment, the use of a plastic tube as an inner liner is described as an example. The plastic pipe is a PP-R pipe or a PVC-U pipe. Referring to fig. 1, the main body of the cast iron composite pipe is a socket cast iron pipe 10 which has a bearing end and a plug end, the cast iron pipe is integrally cast and formed and is generally made of nodular cast iron, and the pipe blank structure of the cast iron pipe is basically the same as that of the prior art. The outer surface of the cast iron pipe 10 is coated with an anticorrosive paint to form an outer anticorrosive layer 11, the inner layer is bonded with a plastic pipe 30 through cement mortar 20, and the two ends of the plastic pipe are repaired by using a hot air blower to form flanges 31 at the two ends.

The inner wall of the cast iron pipe does not need to be polished, and the smoothness and the roundness of the inner surface do not have special requirements. The inner wall of the spigot-and-socket cast iron pipe 10 is directly coated by cement mortar, the coating thickness is controlled to be about 1-2 cm, the cement mortar is used for direct leveling, the process of polishing and leveling the inner wall of the cast iron pipe is omitted, sand blasting and rust removal can be carried out before the cement mortar is leveled according to needs, and rust removal can be avoided if rust is not serious. After the cement mortar is hardened between the plastic pipe and the cast iron pipe, the cement mortar is mainly used for bearing the liquid pressure in the inner wall of the plastic pipe, namely, the pipe expansion is avoided due to the coating of the hardened cement mortar layer and the cast iron pipe on the periphery of the plastic pipe.

The outer surface of the plastic pipe 30 used as the lining is coated with a small amount of cement mortar in order to ensure that the cement mortar forms dense filling between the cast iron pipe and the plastic pipe and prevent local hollows in the process of smoothly drawing the lining plastic pipe into the cast iron pipe, and the bearing pressure of the plastic pipe is transferred to the cast iron pipe because the plastic pipe and the cast iron pipe are filled with the cement mortar.

In order to ensure that the cast iron pipe 10 and the plastic pipe 30 are bonded together, it is necessary to treat the two ends of the plastic pipe, in particular, to clean the two ends of the plastic pipe and to make the two ends have a 15 cm excess. The specific treatment process comprises the following steps: the method comprises the steps of heating the outer end of a plastic pipe (usually about 15 cm) by using heating equipment, setting the temperature of the plastic pipe 30 to be about 250 ℃ 15 cm away from a pipe end, enabling the end of the plastic pipe to deform plastics after heating, compacting and attaching a melting part to the pipe orifice of a cast iron pipe at the corresponding end by using a special tool, closing up and bonding by using a small amount of bonding agent according to needs, forming an anti-corrosion lining layer inside the cast iron pipe by using the plastic pipe after treatment, and forming flanges 31 at two ends.

Furthermore, the outer surface of the pipe of the cast iron pipe is sprayed with plastic, the thickness of the sprayed plastic is about 0.5mm, and an outer anticorrosive layer 11 is formed.

Of course, the socket cast iron pipe 1 described in this embodiment may be other socket metal pipes, such as socket steel pipes. The spigot-and-socket cast iron pipe 1 can also be a non-spigot-and-socket metal pipe.

Referring to fig. 2, in the female connection, sealing is performed using a rubber seal 40, and in fig. 2, two rubber seals are used.

It is possible to realize a concentric or non-concentric arrangement between the cast iron pipe and the plastic pipe, i.e. an eccentric arrangement between the cast iron pipe and the plastic pipe is also possible.

Example 2

The difference between the first embodiment and the second embodiment is that the plastic pipe in the inner liner in the present embodiment is replaced by a copper pipe, that is, the inner liner is a copper pipe. The pipe penetrating process is basically the same as the first embodiment, except that after the copper pipe is fixed, the ends of the two ends of the copper pipe are flattened by heating and matching with a copper hammer to form flanges, and the cast iron pipe with the structure has application value in specific fields. In this embodiment, the copper pipe can be a thin-walled copper pipe due to the presence of the cement mortar filling layer under the condition of bearing the liquid pressure in the pipe.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention and do not limit the scope of the present invention, and various modifications and improvements of the present invention by those skilled in the art without departing from the spirit of the present invention are intended to fall within the scope of the present invention defined by the claims.

Claims (5)

1. The cast iron composite pipe comprises a cast iron pipe, wherein a tubular inner lining layer is fixed in the cast iron pipe through cement mortar, the cast iron pipe is a socket joint type nodular cast iron pipe, an outer anticorrosive layer is arranged on the outer surface of the cast iron pipe, and flanges for coating the cement mortar layer are arranged at pipe orifices at two ends of the tubular inner lining layer.

2. The cast iron composite pipe according to claim 1, wherein the tubular inner liner is one of a PP-R pipe, a PVC-U pipe, a stainless steel pipe, or a copper pipe.

3. The cast iron composite pipe according to claim 1, wherein the cement mortar has a thickness of between 1 cm and 2 cm.

4. The cast iron composite pipe as claimed in claim 1, wherein the cast iron pipe and the tubular inner liner are concentrically disposed.

5. The cast iron composite pipe as claimed in claim 1, wherein the cast iron pipe and the tubular inner liner are eccentrically disposed.

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