JPH0250858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for easily, reliably and strongly lining a metal pipe having branch pipes with a thermoplastic resin pipe (hereinafter abbreviated as "resin pipe"), and an adhesive used therein. This invention relates to a chemical coating device.

BACKGROUND ART In fields such as chemical plants that handle highly corrosive fluids, metal pipes (for example, iron pipes, steel pipes) whose inner surfaces are lined with thermoplastic resin pipes are widely used as piping materials for transporting fluids. However, the cheese used as these piping materials, Y
In lined joint pipes of metal pipes that have branch pipes in the main pipe, such as double pipes and cross pipes, there are easily places where corrosive fluids can enter near the branch parts of the branch pipes that branch from the main pipe, and The disadvantage is that it is very difficult to obtain lined tubes that are free of disadvantages.

The present inventor has made extensive studies to solve the above-mentioned conventional drawbacks and to provide a method for lining a metal pipe with a main pipe having branch pipes with a resin pipe more easily, reliably, and firmly than ever before, and a device used therefor. The present invention has been achieved, and the gist thereof is that when lining a metal pipe having a branch pipe 1' in the main pipe 1 with a resin pipe, the opening of the branch pipe 1' that has been lined with the resin pipe 3 in advance is An adhesive applicator 9 is inserted and arranged in the part,
Further, a resin pipe 2 is inserted into the main pipe 1, a heating medium is passed into the resin pipe 2, the diameter of the softened resin pipe 2 is expanded, and the resin pipe 2 is brought into close contact with the inner wall of the main pipe 1. The branch pipe 1' is inserted into the branch pipe 1' through the adhesive application device 9.
The adhesive injected into the resin pipe 3 is applied to the inner wall of the branch pipe 1' lined with the resin pipe 3, and the internal pressure of the heating medium is increased to expand the resin pipe 2 into the branch pipe 1'. The present invention provides a method for lining a metal pipe having a branch pipe, characterized in that the metal pipe is wrapped with a metal pipe and tightly joined to the inner wall of the branch pipe 1', and an adhesive application device 9 used therein as described later.

Hereinafter, the present invention will be explained with reference to the drawings, taking as an example the case where a cheese having a flange is lined with a hard vinyl chloride resin pipe (hereinafter abbreviated as "PVC pipe"). A schematic vertical cross-sectional view explaining one embodiment of the lining method of the present invention step by step (however, FIG. 3 is an enlarged partial cross-sectional view), and FIG. 5 shows a main pipe 1 and a branch pipe 1 lined by the method of the present invention. FIG. 2 is a schematic longitudinal cross-sectional view of an example of a cheese having a flange of a metal tube having a flange.

FIG. 1 shows an embodiment in which a main pipe 1 with a flange 4 has a branch pipe 1' with a flange 4', and a branch pipe 1' of a metal pipe is lined with a resin pipe (for example, a PVC pipe) 3. Various methods are used to perform this lining,
For example, a heat-expandable resin tube 3 may be inserted and heated to enlarge its diameter and bring them into close contact. In addition, since the branch pipe 1' is generally smaller in size than the main pipe 1,
A pre-formed short pipe (a flange portion may also be formed) may be inserted and glued. In this case, the short pipe should be inserted to the point where the inner diameter of the branch pipe 1' remains unchanged. do. When lining a metal pipe with such a resin pipe, the inner surface of the metal pipe (both the main pipe and branch pipes) is usually first surface-treated by pickling or sandblasting, and then treated with an adhesive (e.g., rubber-based or synthetic resin-based). It is advisable to apply adhesive (adhesive). Apply adhesive to the resin pipe in the same way.

Next, as shown in FIG. 2, a plurality of adhesive discharge ports 93 are arranged radially around the outer periphery of the tip of the branch pipe 1', which is lined with the resin pipe 3 in advance as shown in FIG. An adhesive applicator 9 which also serves as a stopper and has a branch pipe insertion part 92 provided therein is installed by inserting the branch pipe insertion part 92 to a depth halfway into the lined resin pipe 3. In this case, the adhesive applicator 9 can be fixed to the flange 4' of the branch pipe 1' with bolts by forming a flange part 91 at the upper end as shown in FIG. 2 and providing bolt holes 97 therein. can do.

That is, an example of the above-mentioned adhesive application device 9 used in the method of the present invention is shown in more detail in the enlarged partial cross-sectional view in FIG. 3, the bottom view in FIG.
As shown in the sectional view taken along the line A-A in FIG. It has a branch pipe insertion part 92 with a small outer diameter, an adhesive reservoir part 95 is bored in the upper center of the branch pipe insertion part 92, and a plurality of adhesive discharge ports 93 are provided on the outer periphery of the distal end of the insertion part 92. are provided in a downwardly outward radial manner, and the inside of the insertion portion 92 is provided with a plurality of adhesive conduction paths 94 that communicate the adhesive reservoir portion 95 with each of the plurality of adhesive discharge ports 93, and a flange 91 It is preferable to use a device in which a plurality of ventilation holes 96 are provided at positions adjacent to the outer side of the base of the branch pipe insertion portion 92, and a plurality of fixing bolt holes 97 are provided in the outer peripheral portion of the flange 91.

On the other hand, as shown in FIG. 2, a resin pipe 2 is attached to the main pipe 1.
(which may or may not have thermal expandability) is inserted, an intermediate plate 5 and a reducer 7 are connected to both ends of the main pipe 1, respectively, and the end of the resin pipe 2 is folded back and a blank flange 8 is attached to it. Cover and fix.

Once the preparations are completed as described above, the heating medium is introduced from the introduction pipe 12 provided on the blind flange 8 fixed to one end of the main pipe 1, and the heating medium is introduced into the lead-out pipe 13 of the similar blind flange 8 at the other end of the main pipe 1. Emit more. The heating medium may be a gas such as air or water vapor, or a liquid, but a liquid is preferable from the operational and operational standpoints. The liquid may be an oil such as mineral oil, but a water-soluble liquid such as polyethylene glycol or glycerin is preferred because it is easy to wash afterwards. The heating medium is first introduced into the lining resin pipe 2 of the main pipe 1 at its softening temperature, and when the resin pipe 2 softens, the internal pressure of the heating medium is sequentially increased to expand the diameter of the softened resin pipe 2. , 3rd
As shown in the enlarged partial cross-sectional view of the fiber, the resin pipe 2 is brought into close contact with the inner wall of the main pipe 1, and at the same time, the portion of the resin pipe 2 corresponding to the branch part of the branch pipe 1' is inflated and penetrated into the interior of the branch pipe 1'. In this state as shown in FIG.
When the adhesive is injected inside, the adhesive passes through adhesive conduction paths 94 that extend radially downward and outward from the adhesive reservoir 95 at the center, and is provided at a suitable number of radially downwardly outwards around the outer periphery of the tip. The adhesive is discharged smoothly and uniformly from the adhesive discharge port 93 to the innermost part of the branch pipe 1'. The adhesive discharged in this way is
It is applied to the slightly lower end of the resin pipe 3 lined in the branch pipe 1' to be bonded, and flows along it to the innermost part of the branch pipe 1', and the main pipe at the boundary between the main pipe 1 and the branch pipe 1' is coated. The resin is supplied and applied to the gap formed by the inner wall of resin tube 1 and the outer surface of resin tube 2 (10 in FIG. 3). Note that this adhesive application operation may be performed during the process of expanding the diameter of the resin pipe 2 and bringing it into close contact with the inner wall of the main pipe 1.

After the above adhesive application operation is completed, by further increasing the internal pressure of the heating medium in the resin pipe 2, the branch pipe 1' of the resin pipe 2 is changed from the state shown in FIG.
The part of the resin pipe 3 lined with the branch pipe 1' is further inflated until it reaches the bottom of the branch pipe insertion part 92 of the adhesive applicator 9 inserted into the branch pipe 1'. The hem of the bulge of the resin pipe 2 lined with the main pipe 1 is brought into close contact with the lower end of the pipe. Thus, as shown in Figure 4,
The lining resin pipe 3 of the branch pipe 1' and the lining resin pipe 2 of the main pipe 1 that has entered into the branch pipe 1' are overlapped with the adhesive applied uniformly, and can be reliably and firmly bonded.

In the method of the present invention, the resin pipe for lining the metal pipe having the main pipe 1 and the branch pipe 1' may be made of vinyl chloride resin (soft or hard), vinyl chloride copolymer resin, polyethylene, polypropylene, styrene resin ( Any thermoplastic resin conventionally known for lining, such as polystyrene or ABS resin, can be used.

In addition, as shown in FIGS. 3 and 6 to 7, the adhesive applicator 9 used for carrying out the method of the present invention has a branch pipe insertion portion 92 of the flange 91.
A plurality of ventilation holes 96 are provided at positions adjacent to the outer side of the root, and the outer diameter of the branch pipe insertion portion 92 is made slightly smaller than the inner diameter of the lined branch pipe 1', so that the gap between the two is communicated with the ventilation holes. The reason for this is that when the lining resin pipe 2 of the main pipe 1 is expanded,
Adhesive application device 9 in the space surrounded by the inner walls of the resin pipe 2 and the main pipe 1 and inside the resin pipe 2 and the branch pipe 1'
This is to remove air from the space between the bottom and the bottom. (In addition, in FIGS. 2 and 4, illustration of the above-mentioned ventilation hole 96 is omitted.)
As shown in the figure and Fig. 4, the flange 4 of the main pipe 1
If the intermediate plate 5 between the flange 17 and the reducer 7 is also provided with an exhaust hole 6 that penetrates inside and out,
Air is also vented from this exhaust hole 6 when the resin tube 2 is expanded. After further increasing the internal pressure of the heating medium to obtain the state shown in Figure 4, insert the resin tube 2 as necessary.
It is preferable to carry out the heat treatment because it eliminates internal strain and there is no risk of deformation later.

An example of each operation condition when performing each operation performed on the lining resin pipe 2 of the main pipe 1 described above using a PVC pipe as the resin pipe 2 is as follows: First, softening of the PVC pipe is performed. In the operation, a heating medium (polyethylene glycol) is passed through at 110℃ for 10 minutes, and then the diameter expansion operation of the PVC pipe is divided into ^three stages.
The second stage is 110 °C and 5 Kg/cm ² for 1 min, the third stage is 110 °C and 10 Kg/cm ² for 1 min, and the final cooling operation is 15 °C and 10 Kg/cm ² of medium. It was run for 5 minutes.

For example, as shown above, the type of resin pipe is determined,
Once the media passage conditions are set, an adhesive supply tank and multiple media tanks maintained at different temperatures are installed, and the valves attached to the piping are operated by a timer to automate the entire operation. It is also possible to improve productivity.

After the main pipe 1 and the metal pipe having the branch pipe 1' are lined with resin pipes in the order shown in FIGS. 1 to 4 as described above, the adhesive coating device 9
Remove the attached jigs such as the blind flange 8, reducer 7, and intermediate plate 5 from the main pipe 1, and remove the tip of the part of the resin pipe 2 that enters the branch pipe 1' (i.e., 12 in Fig. 4). The present invention as shown in FIG. 5 is made by cutting out the portion shown in FIG. A lined product is obtained by the method.

As described in detail above, according to the method and apparatus of the present invention, when joining the lining resin pipes 2 and 3 of the main pipe 1 and the branch pipe 1', the adhesive applicator 9 selectively applies adhesive to only the parts to be bonded. In addition, the adhesive can be supplied extremely smoothly and applied to the required areas easily, reliably, and evenly, which not only eliminates the manual work involved in conventional adhesive application operations, but also eliminates the need for adhesive application equipment. 9 acts as a stopper and delays the volatilization of the solvent from the applied adhesive. The adhesive bonding of the lap part with the lined resin pipe 3 can be particularly reliably and strongly finished, and as a result, even if the main pipe has a branch pipe and the resin pipe is lined with a metal pipe, there will be no damage to the area near the branch part of the branch pipe. This is a metal lined pipe with branch pipes that has significantly superior safety and durability, and can overcome the drawbacks of the conventional method, such as the creation of points where corrosive fluids can easily enter, which is difficult to prevent. can be produced easily, which is a remarkable effect of industrial value.

[Brief explanation of drawings]

FIGS. 1 to 4 are schematic vertical cross-sectional views (however, the third
(The figure is an enlarged partial cross-sectional view), Figure 5 is a schematic vertical cross-section of an example of a metal tube lined by the method of the present invention, and Figure 6
The figure is a bottom view of an example of an adhesive coating device used in the method of the present invention, and FIG. 7 is a cross-sectional view taken along line A--A in FIG. 6. DESCRIPTION OF SYMBOLS 1... Main pipe, 1'... Branch pipe, 2... Main pipe lining resin pipe, 3... Branch pipe lining resin pipe, 9... Adhesive applicator, 91... Flange, 92... Branch pipe insertion part, 93...
Adhesive discharge port, 94...Adhesive conduction path, 95...Adhesive reservoir, 96...Vent hole.

Claims (1)

[Scope of Claims] 1. When lining a metal pipe having a branch pipe 1' in the main pipe 1 with a resin pipe, an adhesive applicator 9 is inserted into the opening of the branch pipe 1' which has been lined with the resin pipe 3 in advance. In addition, a resin pipe 2 is inserted into the main pipe 1, a heating medium is introduced into the resin pipe 2, the diameter of the softened resin pipe 2 is expanded, and the resin pipe 2 is brought into close contact with the inner wall of the main pipe 1. Alternatively, the adhesive injected into the branch pipe 1' through the adhesive application device 9 during the adhesion process is applied to the inner wall of the branch pipe 1' lined with the resin pipe 3 to increase the internal pressure of the heating medium. A method for lining a metal pipe having a branch pipe, characterized in that the resin pipe 2 expanded into the branch pipe 1' is wrapped with the lining resin pipe 3 and tightly joined to the inner wall of the branch pipe 1'. 2. In an adhesive applicator used when lining a metal pipe with a resin pipe having a main pipe 1 and a branch pipe 1',
Adhesive application characterized in that a branch pipe insertion part 92 inserted into the opening of the branch pipe 1' is provided with a plurality of adhesive passages 94 communicating radially around the outer periphery of the distal end of the insertion part 92. Device.