JPH09187840A - Manufacture of flanged resin lining steel pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent separation or the like from developing at the interface between a main body resin lining layer and a flange resin lining layer due to the thermal expansion and contraction. SOLUTION: This manufacturing method is to form a flange resin lining layer running from a flange surface 12 to a main body resin lining layer 2 by injection molding to a flanged steel pipe 1 having a steel pipe main body 11, a flange 12 provided at the end of the steel pipe main body 11 and the main body resin lining layer 2 covering the inner wall surface of the steel main body 11 to the neighborhood of the end of the pipe. The injection molding of the resin lining layer is performed under the state that the end of the main body resin lining layer 2 is heated with a forming pin 31, which is equipped with a heating means 33 and inserted so as to fit to the end of the main body resin lining layer 2 of the flanged steel pipe 1, heated with the heating means 33 up to the neighborhood of resin melting temperature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a resin-lined steel pipe with a flange by lining a resin from the inner surface of a flanged steel pipe having a flange for joining to the pipe end to the pipe end flange surface.

[0002]

2. Description of the Related Art A steel pipe with a flange, which is used as a pipe material in which a flange is integrally provided at the end of a steel pipe body,
For the purpose of increasing the corrosion resistance and the like, there is a steel pipe body in which a resin is lined from the inner surface to the pipe end flange surface. When such a resin-lined steel pipe with a flange is manufactured, if there is a resin-free portion from the inner surface of the pipe end portion to the flange surface, corrosion may progress from that portion during use. Therefore, in manufacturing, it is necessary to form the lining layer so that the resin exists without interruption not only on the inner surface of the steel pipe but also from the inner surface of the pipe end portion to the flange surface.

Therefore, conventionally, a resin pipe longer than the steel pipe is inserted into the steel pipe and expanded to line the inner surface of the steel pipe, and then the end portion of the resin pipe is flanged along the pipe end flange surface of the steel pipe. Returning method (for example, JP-A-49-49)
No. 99370), or a method of expanding a resin pipe and at the same time integrally expanding and molding a flange portion (see, for example, JP-A-54-29382), a resin lining steel pipe with a flange is manufactured.

However, according to the conventional manufacturing method using the above-mentioned flanged work, after heating and softening the end portion of the resin pipe for the inner surface lining inserted in the steel pipe with the flange,
As described above, the portion is subjected to the flange-back processing and is brought into close contact with the pipe end flange surface. Therefore, among thermoplastic resins, it is applicable to resins having relatively good elongation and excellent workability such as hard vinyl chloride resin, but resins called engineering plastics that have a high melting point and are difficult to extend, such as polyvinylidene fluoride. (PVDF),
It is not applicable or extremely difficult to apply to resins such as polyphenylene sulfide (PPS) and polyether ether ketone (PEEK).

Therefore, in the conventional case, when lining the portion from the inner surface of the steel pipe main body of the flanged steel pipe to the pipe end flange surface with a resin, only a resin which can be subjected to the above-mentioned flange-back processing and the use of an adhesive is used. However, there is a problem in that the type of lining resin and the product performance are limited accordingly.

[0006]

Therefore, the applicant of the present invention has previously proposed the following method for producing a flanged resin-lined steel pipe (Japanese Patent Application No. 5-276793).
issue). That is, this manufacturing method, as shown in FIG.
First, a flanged steel pipe 100 is prepared in which a flange 102 is integrally provided at the end of the steel pipe body 101, and a body resin lining layer 104 is formed on the inner surface of the steel pipe body 101. The main body resin lining layer 104 is the steel pipe main body 1
01 After applying the adhesive 103 to the inner surface, the steel pipe body 10
A synthetic resin pipe slightly shorter than 1 is inserted into the steel pipe main body 101, and the steel pipe main body 101 and the synthetic resin pipe are bonded and integrated with each other via an adhesive 103.

Next, a molding pin 105 having a diameter substantially the same as the inner diameter of the main body resin lining layer 104 is inserted from the end portion of the steel pipe main body 101 so as to be fitted to the front end portion of the main body resin lining layer 104, and further with a flange. An injection molding die 106 is set at the end of the steel pipe 100. And the heater 10
After heating from the outside of the steel pipe main body 101 by 9 to heat the end portion of the main body resin lining layer 104 to near the softening point, a resin melted by heating to a predetermined temperature is injected into the cavity 107 as shown in FIG. Then, by cooling and solidifying, the flange 102 is removed from the inner surface of the end of the steel pipe body 101.
Body resin lining layer 10 by injection molding over the surface
The flange resin lining layer 108 that is connected and integrated with 4 is formed.

According to this method, it is not necessary to rework the end portion of the inner surface lining resin pipe. Therefore, as with the engineering plastics such as PPS described above, the lining is difficult because it has difficult physical properties such as dimensional stability, heat resistance, chemical resistance, etc. The resin that could not be used as a raw material can be used, and thus it is possible to produce various flanged resin-lined steel pipes having excellent performance by utilizing the physical properties of the resin.

However, the above-mentioned manufacturing method proposed by the present applicant has the following problems. That is, in the case of the above manufacturing method, when the flange resin lining layer 108 is injection-molded, first, the steel pipe main body 101
Of the main body resin lining layer 104 to heat the end portion of the main body resin lining layer 104 to near the softening point to further improve the adhesion at the interface between the main body resin lining layer 104 and the flange resin lining layer 108. However, since the steel pipe body 101 is heated from the outside, the heating may be insufficient and the adhesiveness at the interface may become non-uniform.

Then, in this way, both running layers 10
If the fusion at the interfaces of 4,108 is partially insufficient, thermal expansion and contraction of the resin may cause peeling at the interfaces between the two, resulting in failure to exert a sufficient anticorrosion effect. In view of such circumstances, the present invention has excellent bondability between the main body resin lining layer and the flange resin lining layer, and peeling or the like does not occur at the interface between the main body resin lining layer and the flange resin lining layer due to thermal expansion or contraction. An object of the present invention is to provide a method for manufacturing a resin-lined steel pipe with a flange.

[0011]

In order to achieve such an object, a method for manufacturing a resin lining steel pipe with a flange according to the invention of claim 1 (hereinafter referred to as "manufacturing method of claim 1") is Steel pipe main body, a flange provided at the end of the steel pipe main body, and a flanged steel pipe having a main body resin lining layer that covers the inner wall surface of the steel pipe main body to the vicinity of the pipe end, from the flange surface to the main body resin lining layer A method of manufacturing a resin lining steel pipe with a flange for forming a flanged resin lining layer by injection molding, wherein a molding pin having a heating means is inserted until it is fitted to an end of the resin lining layer of the main body of the flanged steel pipe. Then
The flange resin lining layer is injection-molded while the end portion of the main body resin lining layer is heated to near the melting temperature of the resin by the molding pin heated by the heating means.

On the other hand, a method of manufacturing a resin-lined steel pipe with a flange according to the invention of claim 2 (hereinafter, referred to as "manufacturing method of claim 2") is the same as that of the manufacturing method of claim 1 above. While the pin is fitted to the end of the main body resin lining layer, the end surface of the slide pin slidably fitted on the molding pin is closely attached to the end surface of the main body resin lining layer. After heating the end portion to near the resin melting temperature, the slide pin was retracted, and the flange resin lining layer was injection-molded.

On the other hand, the method of manufacturing a resin-lined steel pipe with a flange according to the invention of claim 3 (hereinafter referred to as "manufacturing method of claim 3") is the manufacturing method of claim 1 or claim 2. In addition to the above configuration, the recesses are formed at a predetermined pitch on the inner peripheral surface of the portion of the main body resin lining layer where the molding pin is fitted.

A method of manufacturing a resin-lined steel pipe with a flange according to the invention of claim 4 (hereinafter, referred to as "manufacturing method of claim 4") comprises a slide in addition to the structure of the manufacturing method of claim 2. The pin has a thread forming part on the outer peripheral surface of the tip that can bite into the inner peripheral part of the end of the main body resin lining layer.The thread forming part of the slide pin is connected to the end of the main body resin lining layer. The inner peripheral portion of the main body resin lining layer is screwed into the inner peripheral portion of the main body resin lining layer, and the end portion of the main body resin lining layer is heated to near the resin melting temperature in that state. The slide pin is retracted while being rotated in the circumferential direction so as to be disengaged from the screw portion formed in the portion, and the flange resin lining layer is injection-molded.

In the above structure, the method of providing the resin lining layer on the steel pipe body is not particularly limited. For example, after applying an adhesive to the inner peripheral surface of the steel pipe body, a synthetic resin pipe shorter than the steel pipe body is used. There is a method of inserting it inside and integrating it with the steel pipe body. When the steel pipe main body and the synthetic resin pipe are joined and integrated, it is preferable to insert the synthetic resin pipe into the steel pipe main body and then reduce the diameter of the steel pipe main body or expand the diameter of the synthetic resin pipe.

As the resin for forming the lining layer, vinyl chloride resin, polyvinylidene fluoride (PVDF), polyethylene, crosslinked polyethylene, polybutene, phenylene sulfide (PPS), polyether ether ketone (PEEK), fluororesin (eg PVDF). ) And the like.

The vicinity of the melting temperature varies depending on the type of resin, but generally, the melting temperature of the resin is preferably about ± 20 ° C., and the lower the melting temperature, the outer shape of the resin does not change and the appearance is excellent. -1 because of excellent releasability from the molding pin
5 to -5 ° C is more preferable. Incidentally, when both resin lining layers are vinyl chloride resin-vinyl chloride resin, the heating temperature is preferably about 160 to 200 ° C.

Further, the flanged steel pipe includes not only those in which the flanges are provided at both ends of the steel pipe body, but also those in which the flanges are provided only at one end of the steel pipe body. Further, in addition to the above configuration, it is preferable to cut out the edge of the main resin lining layer in a stepped shape or a tapered shape.

When the step is cut out, the length of the parallel part of the step is preferably 5 mm or more. Although the thickness of the step varies depending on the thickness of the main body resin lining layer, when the thickness of the main body resin lining layer is 2 mm or less, it is preferably half or more of the thickness, and when the thickness of the main body resin lining layer exceeds 2 mm, 1 to 3 within the range of half the wall thickness
mm is preferable.

Further, in the case of notching in a tapered shape, it is preferable that the taper is 60 ° or less, particularly 45 ° or less from the steel pipe main body side toward the inner wall surface of the main body resin lining layer.

Further, in the structure of the manufacturing method according to the third aspect, the recesses may be continuous in a groove shape or may be scattered in an island shape. Further, in the case of forming the groove shape, the grooves may be continuous in a spiral shape or may be arranged at a desired pitch in the tube axis direction.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 4 show one embodiment of the manufacturing method of the present invention in the order of steps. This manufacturing method will be described below in the order of steps.

As shown in FIG. 1, first, a flanged steel pipe 1 is prepared in which a main body resin lining layer 2 having tapered notches 21 at both ends is integrally provided on an inner surface of a steel pipe main body 11. To do. For the main body resin lining layer 2, a flanged steel pipe 1 in which flanges 12 and 12 are integrally provided at both ends of a steel pipe main body 11 is prepared, and an adhesive 13 is applied to the inner surface of the steel pipe main body 11 of the flanged steel pipe 1. After that, a synthetic resin pipe (not shown) to be the main body resin lining layer 2 is inserted into the steel pipe main body 11 of the flanged steel pipe 1 and joined and integrated with an adhesive. The notch 21 may be formed by notching the edge of the synthetic resin pipe in advance, or may be notched after being joined and integrated with the steel pipe 1.

As shown in FIG. 2, the injection mold 3 is set on the flange 12, and the molding pin 31 of the injection mold 3 is inserted inside the flanged steel pipe 1 to form the molding pin 3
The tip end portion of 1 is fitted to the end portion of the main body resin lining layer 2, and the tip end surface 32 a of the slide pin 32 slidably inserted into the molding pin 31 is brought into close contact with the cutout portion 21.

That is, the tip surface 32 of the slide pin 32
a is a tapered surface having the same angle as the notch 21.

The molding pin 31 and the slide pin 32 are provided by a cartridge heater (hereinafter referred to as "heater") 33 as a heating means provided in the molding pin 31.
Is heated to near the melting temperature of the resin forming the main body resin lining layer 2 to bring the end portion of the main body resin lining layer 2 into a molten state or a state close to the molten state. After heating the main body resin lining layer 2 to near the melting temperature, the slide pin 32 is retracted as shown in FIG. 3, and the molten resin is injected into the formed cavity 34 to mold the flange resin lining layer 5.

After cooling, the injection molding die 3 is removed to obtain a resin lining steel pipe A with a flange shown in FIG. As described above, according to the method for manufacturing the resin lining steel pipe A with the flange, when the flange resin lining layer 5 is injection-molded, the end portion of the main body resin lining layer 2 is brought into a molten state or a state close to the molten state by the molding pin 31. Therefore, the molten resin injected into the cavity 34 and the end portion of the main body resin lining layer 2 are well fitted to each other, and the flange resin lining layer 5 and the main body resin lining layer 2 are firmly joined and integrated at the interface.

Further, since the end portion of the main body resin lining layer 2 is directly heated by the heater 33 built in the molding pin 31, it is heated almost uniformly over the whole. Therefore, the flange resin lining layer 5 and the main body resin lining layer 2 are evenly fused over the entire surface, and peeling or the like does not occur at the interface due to thermal expansion and contraction, and the flanged resin always has sufficient strength and corrosion resistance. A lining steel pipe A can be provided.

Moreover, since the slide pin 32 also heats the end surface of the main body lining layer 2, the heating time can be shortened and the productivity is excellent. Of course, after the main body resin lining layer 2 is formed, the flange resin lining layer 5 is separately formed by injection molding from the inner surface of the steel pipe main body 11 to the surface of the flange 12 to the inner surface of the steel pipe main body 11. To the surface of the flange 12 at the pipe end, the resin lining layer is formed without interruption.
Therefore, the end of the resin pipe for the inner surface lining of the steel pipe is flanged as in the past, or the resin short pipe is bonded to the resin pipe with an adhesive and then the end is flanged. Even without doing so, the resin is surely lined from the inner surface of the steel pipe body 11 to the flange 12 surface of the pipe end,
It is possible to manufacture resin-lined steel pipes with flanges even when using a resin that has a high melting point and is difficult to stretch, which makes it difficult to apply a collar and use an adhesive.

In other words, polyvinylidene fluoride (PVDF) and polyphenylene sulfide (PP) are used as the lining material for the resin-lined steel pipe with a flange.
Resins having excellent physical properties such as S) and polyether ether ketone (PEEK) can be used, and products having excellent performance (for example, dimensional stability) can be obtained.

FIG. 5 and FIG. 6 show another embodiment of the method for producing a resin-lined steel pipe with a flange according to the present invention. This manufacturing method will be described below in the order of steps.

As shown in FIG. 5, first, the main body resin lining layer 7 having the spiral grooves 71 as recesses formed on the inner peripheral surfaces of both ends is integrally provided on the inner surface of the steel pipe main body 61. To prepare. For the main body resin lining layer 7, a steel pipe 6 with a flange in which flanges 62 (only one side is shown in the figure) are integrally provided at both ends of the steel pipe main body 61 is prepared. After applying an adhesive to the, a synthetic resin pipe (not shown) to be the main body resin lining layer 7 is inserted into the steel pipe main body 61 of the steel pipe 6 with a flange, and joined and integrated through an adhesive. . The spiral groove 71 may be formed in advance on the inner peripheral surface of the end portion of the synthetic resin pipe, or may be formed after being joined and integrated with the steel pipe 6.

As shown in FIG. 6, while the injection molding die 8 is set on the flange 62, the molding pin 81 of the injection molding die 8 is inserted into the inside of the flanged steel pipe 6 to form the molding pin 8
The tip end of No. 1 is fitted into the portion of the main body resin lining layer 7 where the spiral groove 71 is formed. That is, the peripheral wall of the molding pin 81 comes into close contact with the threads 72 provided on both sides of the spiral groove 71.

The molding pin 81 is heated to near the melting temperature of the resin forming the main building resin lining layer 7 by the heater 82 provided in the molding pin 81, so that the end portion of the main body resin lining layer 7 is melted or melted. Bring it closer.

After heating the main body resin lining layer 7 to near the melting temperature, the molten resin is injected into the cavity 83 to mold the flange resin lining layer 9. After cooling, the injection mold 8 is removed to obtain a resin lining steel pipe A with a flange shown in FIG.

In this manufacturing method, as shown in FIG. 5, a spiral groove 71 is formed on the inner peripheral surface of the end of the main body resin lining layer 7, and the peripheral wall of the molding pin 81 has a narrow thread 72.
Hit only the top of the. Therefore, the heat from the molding pin 81 is easily transferred to the screw thread 72, and the end portion of the main body resin lining layer 7 becomes a molten state or a molten state in a molten state faster. That is, the heating time can be shortened and the productivity can be improved.

7 and 8 show still another embodiment of the method for producing a resin-lined steel pipe with a flange according to the present invention. First, a flanged steel pipe 1 is prepared in which a main body resin lining layer 2 having tapered notches 21 at both ends as shown in FIG. 1 is integrally provided on the inner surface of a steel pipe main body 11.

As shown in FIG. 7, the injection mold 9 is set on the flange 12. The injection mold 9 has a molding pin 91.
A slide pin 92 is externally fitted to the slide pin 92 so as to be slidable and rotatable in the circumferential direction. The slide pin 92 is provided with a screw forming portion 921 on the outer peripheral surface of the tip end portion, which can bite into the inner peripheral end portion of the main body resin lining layer 2 of the resin lining tube 1 with the lining.

The molding pin 91 of the injection mold 9 is inserted into the inside of the flanged steel pipe 1. While rotating the slide pin 91 in the clockwise direction, the thread forming portion 921 is bited into the inner peripheral portion of the end portion of the main body resin lining layer 2 so as to perform thread cutting. In this state, the end portion of the main body resin lining layer 2 is heated to near the melting temperature of the resin by the heater 911 provided inside the molding pin 91, and the end portion of the main body resin lining layer 2 is in a molten state or close to a molten state. Put in a state.

Next, as shown in FIG. 8, the slide pin 92 is moved in the circumferential direction in the counterclockwise direction in which the thread forming portion is removed from the thread portion formed on the inner peripheral portion of the end of the main body resin lining layer 2. Move backward while rotating. Then, a molten resin is injected into the cavity 93 to form a flange resin lining layer. After cooling, the injection molding die 9 is removed to obtain a resin lining steel pipe with a flange.

[0041]

The present invention will be described in more detail below with reference to its examples. (Example 1) With a nominal diameter of 50 A and a thickness of 1.5 mm,
A flanged steel pipe 6 provided with a main body resin lining layer 7 made of vinyl chloride resin in which a spiral groove 71 having a depth of 1.2 mm was formed at an end was prepared, and an injection molding die 8 was set.

The molding pin 81 of the injection molding die 8 was heated by a heater 82 incorporated therein in advance so as to have a surface temperature of 200 to 230 ° C. before being set. Then, the end portion of the main body resin lining layer 7 was heated by the molding pin 81 for 15 seconds or more, and then the molten resin was injected into the cavity to form the flange resin lining layer 9.

In the obtained flanged resin lining steel pipe A, the flange resin lining layer 5 and the main body resin lining layer 2 were uniformly and firmly fused, and peeling did not occur at the interface due to thermal expansion and contraction. .

[0044]

As described above, according to the method for producing a flanged resin-lined steel pipe according to the present invention, as in the method for producing a flanged resin-lined steel pipe previously proposed by the applicant, When lining the portion from the inner surface to the pipe end flange surface, the inner surface of the flanged steel pipe is lined with resin, and then the resin lining layer is formed by injection molding on the pipe end of the steel pipe. It is not necessary to perform end-reverse processing on the end of the pipe, or to join the short pipe made of resin to the resin pipe via an adhesive and then perform end-reverse processing on the end of the short pipe.

Therefore, in the case of manufacturing this kind of flanged resin-lined steel pipe, for example, the above-mentioned PPS is used.
Although it has excellent physical properties such as dimensional stability, heat resistance, and chemical resistance, it cannot be used as a lining material because it is difficult to process the flange and use adhesives. Since a resin can also be used, it becomes possible to manufacture various types of flanged resin-lined steel pipes having excellent performance by taking advantage of the physical properties of the resin.

Moreover, since the end portion of the main body resin lining layer is heated from the outside of the steel pipe main body to the vicinity of the resin softening temperature by the heating means, the molten resin to be the flange resin lining layer is injected. The end of the main body resin lining layer softened by temperature and pressure is well fitted to the molten resin, and the flange resin lining layer and the main body resin lining layer are more firmly joined and integrated at the interface, so that the main resin is thermally expanded and contracted. It is possible to provide a resin lining steel pipe with a flange that does not cause peeling or the like at the interface between the lining layer and the flange resin lining layer and always has sufficient strength and corrosion resistance.

Further, according to the manufacturing method of the second and third aspects, the end portion of the main body resin lining layer can be heated more quickly, and the productivity can be improved.

Further, according to the manufacturing method of the fourth aspect, the inner peripheral surface of the end portion of the main body resin lining layer can be surely melted, and the fusion area is increased, so that the main body resin lining layer is injection-molded. The interface with the resin is fused and integrated, and the fusion strength becomes close to that of the base material. Therefore, it is possible to provide a resin lining steel pipe with a flange that does not cause peeling from the interface due to thermal expansion and contraction and that has both strength and corrosion resistance.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a method for manufacturing a resin lining steel pipe with a flange according to the present invention in the order of steps, and is a cross-sectional view showing a state where a main body resin lining layer is formed on the inner surface of the steel pipe with flange. is there.

FIG. 2 is a diagram showing one embodiment of a method for manufacturing a resin lining steel pipe with a flange according to the present invention in the order of steps, in which an injection molding die is attached to the steel pipe with a flange on which the main body resin lining layer of FIG. 1 is formed. It is sectional drawing of the set state.

FIG. 3 is a diagram showing one embodiment of a method of manufacturing a resin-lined steel pipe with a flange according to the present invention in the order of steps, before retracting the slide pin of the injection mold of FIG. 2 and injecting the molten resin. 3 is a cross-sectional view showing the state of FIG.

FIG. 4 is a cross-sectional view of a resin lining steel pipe with a flange obtained through the steps of FIGS. 1 to 3.

FIG. 5 is a view showing another embodiment of a method for manufacturing a resin lining steel pipe with a flange according to the present invention in the order of steps, and is a cross-sectional view showing a state where a main body resin lining layer is formed on the inner surface of the steel pipe with a flange. is there.

FIG. 6 is a diagram showing another embodiment of the method for manufacturing a resin lining steel pipe with a flange according to the present invention in the order of steps, in which the injection molding die is attached to the steel pipe with a flange on which the main body resin lining layer is formed. It is sectional drawing of the set state.

FIG. 7 is a view showing still another embodiment of the method for producing a resin lining steel pipe with a flange according to the present invention in the order of steps, and is a cross-sectional view showing a state where a main body resin lining layer is formed on the inner surface of the steel pipe with a flange. Is.

FIG. 8 is a view showing another embodiment of a method for manufacturing a resin lining steel pipe with a flange according to the present invention in the order of steps, in which an injection molding die is attached to the steel pipe with a flange on which the main body resin lining layer of FIG. 7 is formed. It is sectional drawing of the set state.

FIG. 9 is a cross-sectional view showing a state before injection molding in the previously proposed method for manufacturing a resin lining steel pipe with a flange.

10 is a cross-sectional view showing a state after injection in FIG.

[Explanation of symbols]

 A Resin lining steel pipe with flange 1 Steel pipe with flange 11 Steel pipe main body 12 Flange 2 Main body resin lining layer 3,9 Injection mold 31,91 Molding pin 32,92 Slide pin 33 Cartridge heater (heating means) 5 Flange resin lining layer 6 Flange Attached steel pipe 61 Steel pipe main body 62 Flange 7 Main body resin lining layer 71 Spiral groove (recess) 8 Injection molding die 81 Molding pin 82 Cartridge heater (heating means) 921 Screw forming part

Claims (4)

[Claims] 1. A flanged steel pipe having a steel pipe main body, a flange provided at an end portion of the steel pipe main body, and a main body resin lining layer that covers an inner wall surface of the steel pipe main body up to the vicinity of the pipe end. A method for producing a resin lining steel pipe with a flange, wherein a flange resin lining layer reaching a main body resin lining layer is formed by injection molding,
Insert the molding pin equipped with heating means until it fits into the end of the main body resin lining layer of the flanged steel pipe, and move the end of the main body resin lining layer to near the resin melting temperature by the molding pin heated by the heating means. A method for producing a resin lining steel pipe with a flange, characterized in that the flange resin lining layer is injection-molded in a heated state. 2. A molding pin fitted to an end portion of a main body resin lining layer, and an end surface of a slide pin slidably fitted on the molding pin is in close contact with an end surface of the main body resin lining layer. The method for manufacturing a flanged resin-lined steel pipe according to claim 1, wherein after heating the end portion of the main body resin lining layer to a temperature near the resin melting temperature, the slide pin is retracted and the flange resin lining layer is injection-molded. 3. The method for producing a resin lining steel pipe with a flange according to claim 1, wherein the main body resin lining layer is provided with concave portions at a desired pitch on an inner peripheral surface of a portion into which the molding pin is fitted. . 4. A slide pin is provided with a thread forming portion on the outer peripheral surface of the tip portion that can bite into the inner peripheral portion of the end of the main body resin lining layer. The inner peripheral portion of the end of the main body resin lining layer is cut into the inner periphery so that the end of the main body resin lining layer is heated to a temperature near the resin melting temperature, and then the thread forming portion is threaded onto the main body resin lining layer. The method for producing a resin lining steel pipe with a flange according to claim 2, wherein the flange resin lining layer is injection-molded while the slide pin is retracted while being rotated in the circumferential direction so as to be disengaged from the screw portion formed on the inner peripheral portion of the end portion of the flange. .