JPH02229631A - Manufacture of compound tube - Google Patents

Abstract

PURPOSE:To manufacture a compound tube being excellent in pressure resistance, external flaw resistance and shape holding property, etc., and also, having flexibility by inserting a lead tube into a corrugated metallic tube, and expinding the lead tube in the inside of the metallic tube. CONSTITUTION:First of all, by rounding a metallic plate in a tubular shape and welding its joint, and thereafter, executing the corrugating working, a corrugated metallic tube 2 is formed. Subsequently, for instance, a lead tube 3 brought to lead extrusion is inserted into the metallic tube 2. Next, both ends of the lead tube 3 are closed up tightly, and by filling the inside of the lead tube 3 with a pressure medium such as gas or a liquid, etc., the lead tube 3 is worked toward the inside peripheral surface of the corrugated metallic tube 2, and also, atmospheric air in a gap 10 formed between the lead tube 3 and the inside peripheral surface of the metallic tube 2 is brought to vacuum formation, by which the lead tube 3 is expanded and the lead tube 3 is allowed to adhere closely to the inside peripheral surface of the corrugated metallic tube 2 and a lead layer 4 is formed. In this regard, it is also possible to improve the quality of the outside surface by providing protective layers 5, 6 on the outside peripheral surface of the corrugated metallic tube 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing a composite pipe. [Prior art and its problems] Aluminum pipes, lead pipes, polyethylene pipes, etc. are conventionally used as long flexible pipes for water supply, gas supply pipes, or for transporting chemicals, etc. However, these conventional pipes do not satisfy all the requirements of being excellent in trauma resistance, internal pressure resistance, corrosion resistance, shape retention, radiation resistance, airtightness, etc., as well as being flexible and easy to install. Ta. For example, aluminum pipes have excellent features such as light weight and flexibility, but have the disadvantage of poor corrosion resistance.Although lead pipes have excellent corrosion resistance, they are too soft and have poor internal pressure resistance. Polyethylene pipes had drawbacks such as poor airtightness. Therefore, the present invention aims to provide a method for manufacturing a composite pipe that satisfies all of the many conditions required for transportation pipes and the like as described above. [Means for solving the problem and their effects] The above technical! The measures taken to solve problem i are as follows.

That is, after forming a corrugated metal pipe, a lead pipe is inserted into the corrugated metal pipe, and then a pressure medium is sealed in the lead pipe to enlarge the diameter of the lead pipe, and the lead pipe is brought into close contact with the inner surface of the corrugated metal pipe. This leads to the formation of a lead layer. In this way, by expanding the diameter of the lead pipe inside the corrugated metal tube, it is possible to easily manufacture a composite pipe having a thin lead layer on the inner surface of the corrugated metal tube. [Example] The structure of a composite pipe to be manufactured by the manufacturing method according to the present invention is as follows. That is, composite pipe 1
As shown in FIG. 1, the corrugated metal tube 2 has a lead layer 4 on the inner surface thereof, which is made by enlarging the diameter of a lead tube 3 and adhering it tightly. As the material for the corrugated metal tube 2, steel, stainless steel, copper, etc. can be used. In addition, the materials for forming the lead pipe 3 include lead and lead alloys (which can be continuously extruded).
(Cu+Te alloy, C alloy, %C alloy, so-called solder, etc.) can be used.

As shown in FIG. 2, the outer peripheral surface of the corrugated metal tube 2 is made of extruded polyethylene, which improves the corrosion resistance of the outer surface of the corrugated metal tube 2 and also serves as a heat-retaining layer in some cases.
A protective layer 5 made of polyvinyl chloride, polybutene, nylon, or the like, or one or more layers of fused polyethylene tape, rubberized cloth tape, etc., wound by taping is provided. Alternatively, in order to efficiently exchange heat on the outer circumferential surface of the corrugated metal tube 2, the corrugated metal tube 2 may not be provided with the heat-insulating protective layer 5, or the outer circumferential atmosphere of the corrugated metal tube 2 may be is a corrosion-resistant gas, e.g. SO
! When there is a risk of contact with liquids such as , S O s, sewage, chemical solutions, or water vapor, the corrugated metal tube 2 should be removed for the same reason as the lead layer 4 is tightly attached to the inner circumferential surface of the corrugated metal tube 2. It is preferable to provide a protective layer 5 made of lead pipe on the outer surface of the tube. When the protective layer 5 is made of lead or a lead alloy, as described above, the thermal conductivity between the inner and outer surfaces of the composite pipe 1 is particularly good. Furthermore, when heat insulation is required, the protective layer 5 is formed of a foamed plastic insulation layer such as foamed polystyrene or foamed polyethylene, or a insulation layer such as glass wool or asbestos. In this case, as shown in FIG. 3, on top of the protective layer 5 made of heat insulating material,
The second protective layer 6, which has the functions of shape retention, trauma prevention, waterproofing, corrosion resistance, and heat insulation, is formed by extruding polyethylene, polyvinyl chloride, polybutene, nylon, etc., or is made of fused polyethylene tape, rubberized cloth tape, etc. It is very preferable to form it by taping. Furthermore, although not shown here, a heat insulating layer is applied to necessary parts of the outer periphery of the lead pipe 3, and then the corrugated metal pipe 2 is covered, and then the diameter is expanded, and the lead layer 4 is attached to the metal pipe 2 through the heat insulating layer. It may be placed in close contact with the In particular, when providing the protective layer 5 of the lead pipe on the outer periphery of the metal pipe 2 for corrosion resistance, the lead layer 5 according to this method is
An effective method is to insert a heat insulating layer between the metal tube 2 and the metal tube 2. In addition, instead of the heat insulation layer, the purpose is to eliminate so-called electrical corrosion between the lead layer 4 and the metal pipe 2 over the entire length of the composite pipe,
An insulating tape or paint that eliminates electrical connection for the purpose of energizing the lead layer 4 or the metal tube 2, or one or more types of adhesive that strengthens the fixation between the lead layer 4 and the metal tube 2. Sometimes a combination is involved. The composite pipe 1 as described above is manufactured by the following method. First, a corrugated metal tube 2 is formed. For example, Figure 5a,
As shown in b and c, a flat metal plate 7 with a thickness of about 0.3 to 2.0 m is rolled into a tubular shape and the seam 8 is TIG, MIG.
Welding is performed by plasma arc, resistance welding, laser welding, electron beam welding, etc., and then corrugated processing is performed to form the corrugated metal tube 2. Next, the corrugated metal tube 2 is welded using, for example, a lead continuous extrusion machine. Insert the extruded lead pipe 3. For example, as shown in FIG. 6, this lead pipe 3 is inserted by inserting the pre-manufactured lead pipe 3 while rounding the metal flat plate 7 when forming the corrugated metal pipe 2 from the metal flat plate 7. go. At this time, the seam 8 of the metal flat plate 7
It is preferable to insert a heat shield plate or a cooling pipe 9 between the metal pipe 2 and the lead pipe 3 so that the inserted lead pipe 3 is not melted by the heat of welding. Another method for inserting the lead pipe 3 is a method that is adopted when the composite pipe is not very long, in which the lead pipe 3 and the corrugated metal pipe 2 having an inner diameter slightly larger than its outer diameter are manufactured in advance. Ok,
The lead pipe 3 is inserted into the corrugated metal pipe 2 from its end. After that, both ends of the lead pipe 30 are sealed, a pressure medium such as gas or liquid is sealed inside the lead pipe 3, and the lead pipe 3 is connected to the corrugated metal pipe 2.
At the same time, by evacuating the atmosphere in the gap 10 formed between the lead pipe 3 and the inner peripheral surface of the corrugated metal pipe 2, the diameter of the lead pipe 3 is expanded and the corrugated metal pipe 2 is processed. A lead layer 4 is formed by bringing a lead pipe 3 into close contact with the inner peripheral surface of the lead pipe 3. At this time, it is preferable to heat the lead pipe 3 to a maximum temperature of 150°C or less to facilitate pipe expansion. The reason why the heating temperature is set at a maximum of 150°C is because heating to a temperature higher than this may cause the strength of the lead pipe 3 to deteriorate, and locally weak parts may be damaged by internal pressure. Next, the internal pressure for expanding the diameter of the lead pipe 3 depends on the inner diameter of the lead pipe, but the maximum pressure is about 50 kg/d, preferably 10 kg/cd or less, even when the corrugated metal pipe 2 has a large diameter. Avoid deforming it. In addition, the method of pressurization is such that if the maximum internal pressure is applied all at once, if there is a local weak point in the lead pipe 3 due to unevenness, that part may be damaged. /cd for 1 hour, then 10
It is preferable to gradually increase the pressure to the highest pressure allowed in terms of design in steps such as kg/cd for 1 hour and then 15 kg/cd for 1 hour.

When the composite pipe 1 is short, the corrugated metal pipe 2 and the lead pipe 3 may be formed separately, and the lead pipe 3 may be inserted into the corrugated metal pipe 2 later. As mentioned above.

The diameter of the lead pipe 3 is expanded after the lead pipe 3 inserted into the corrugated metal pipe 2 is transported to the required location and installed.
A pressure medium may be sealed in the lead pipe 3. Furthermore, the corrugated metal pipe 2 has flexibility due to the corrugation, but this shape also occurs in the lead pipe 3 that is tightly fitted inside, so the corrugation on the inner surface of the lead pipe 3 increases the fluid resistance inside the pipe. In some cases, it becomes large and undesirable. If fluid resistance due to corrugation becomes a problem, the pressure of the pressure medium sealed in the lead pipe 3 should be adjusted to approximately 60 to 1% of the theoretical breaking tensile strength of the composite pipe before corrugation.
It is preferable to further increase the pressure to 00% and leave it for a certain period of time, for example, 5 to 60 minutes, to stretch out the waves in the corrugated metal tube 2.

Next, when using the composite pipe 1 as a heat pipe, if a wick is not required, just seal both ends, and if a wink is required, the lead pipe 3 is covered with wick material 11 and hydraulic fluid is sealed. ．． To create a wink inside the lead pipe 3, do the following. That is, when carbon fiber, metal mesh, etc. are used as the wick material 11 and fixed to the inner surface of the lead pipe 3, stainless steel is used to maintain the shape of the wick material 11, as shown in FIG. , copper, nylon, FR
Form a spiral 12 with P etc., and this spiral 12
Wrap the wick material 11 around the outer circumference of the wick material 1.
1 to the spiral 12 using a binder material (cloth tape, metal tape, wire, etc.) 13 as necessary. Next, the wink material 11 fixed to this spiral 12
As shown in FIG. 8, the lead continuous extruder 14, which can wrap a long object inside,
Lead pipe 3 is formed by continuously coating lead around pipe 1. The lead pipe 3 formed in this manner may be cut into a certain size or wound around a drum, if necessary. Next, this lead pipe 3 is inserted into the corrugated metal tube 2, and then the diameter is expanded to bring it into close contact with the inner surface of the corrugated metal tube 2. In addition, in the case of long heat pipes, if the required length is known, it can be sealed and filled with hydraulic fluid at the factory, but if the required length is not limited, it can be wrapped in a drum. After laying a composite pipe 1 with wick material 11 stretched on the inner surface of the composite pipe 1, the air inside the composite pipe 1 is evacuated from both ends or one end of the composite pipe 1, and then a required amount of hydraulic fluid is filled in. , then a heat pipe is obtained by sealing both ends. When a heat pipe is manufactured in this way, it can be well adapted to the various conditions of the site where it is installed, so that a more practical heat pipe can be obtained from the viewpoint of the installation method.

In addition, when this heat pipe is provided with a heat insulating layer and an insulating layer in the center part to form a heat insulating part 15 as shown in FIG. In this, the heat absorption part 16 and the heat radiation part 17
When parts A and B surrounding both are air, remove the heat insulating layer and protective layer from both the heat absorbing part 16 and the heat dissipating part 17, leaving the corrugated metal tube 2 as it is, and attach the fin 18 to that part if necessary. . If part A is steam or high temperature water and part B is empty.
In the case of corrosion, it is preferable to cover the corrugated metal tube 2 at least in section A with a lead pipe on the outside for corrosion resistance. However, it is not necessarily necessary to cover the entire length with the lead pipe, and it is sufficient to cover the metal surface of the heat absorbing part 16 that contacts part A to a minimum. Of course, in this case, instead of using a lead pipe to cover the corrugated metal tube 2 in the A section, the corrugated metal tube may be protected from corrosion by using a thin corrosion-resistant material such as Teflon, although the heat exchange rate will be reduced. Regarding section B, if it is necessary to impart corrosion resistance to the corrugated metal tube 2, the same treatment as for section A described above may be taken. Of course, if the material of the corrugated metal tube is stainless steel or the like, and the surrounding conditions are not too corrosive, there is no need to coat it with lead even in a liquid atmosphere, and it goes without saying that the metal tube can be used as is.

〔effect〕

According to the manufacturing method of the present invention, it is possible to manufacture a composite pipe that has excellent pressure resistance, trauma resistance, shape retention, corrosion resistance, radiation resistance, airtightness, etc., and also has flexibility. Then, since the diameter of the lead pipe is expanded, for example, the wall thickness is 2 to 3 ff.
It is also possible to expand the diameter of the lead pipe of III1 and form a thin lead layer on the inner surface of the corrugated metal tube, which is difficult to maintain a tubular shape with lead alone, and more preferably with a thickness of less than 200 mm, more preferably less than 100 mm. It is possible to manufacture a lightweight composite pipe while having the following advantages.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing an embodiment of a composite pipe to be manufactured by the manufacturing method according to the present invention, FIG. 4 is a cross-sectional view showing a state in which a lead pipe is inserted into a corrugated metal pipe, and FIG. Figures 5(a), (b), and (C) are diagrams showing an example of a method for manufacturing a corrugated metal tube, Figure 6 is a schematic diagram showing a state in which a lead pipe is inserted into a corrugated metal tube, and Figures 7 and 8 are The figure is a schematic diagram showing the process of installing wick material into a lead pipe, and Figure 9 is a schematic diagram showing an example of a heat viper. 1... Composite pipe, 2... Corrugated metal pipe, 3... Lead pipe, 4...
...Lead layer, 5, 6...Protective layer, 7...
...metal plate, 11...wink material, 12...spiral. Agent Fumi Kamata Figure 5

Claims (4)

[Claims] (1) After forming a corrugated metal tube, insert a lead pipe into the corrugated metal tube, then fill the lead pipe with a pressure medium to expand the diameter of the lead pipe, and tightly fit the lead pipe to the inner surface of the corrugated metal tube. A method for manufacturing a composite pipe in which a lead layer is formed. (2) The composite pipe according to claim 1, wherein the corrugated metal tube is formed by forming a metal plate into a tubular shape, welding the seams, and then applying corrugation processing. Production method. (3) The method for manufacturing a composite pipe according to claim 1 or 2, characterized in that a lead pipe is inserted when forming the metal plate into a tubular shape. (4) The corrugated metal pipe and the lead pipe are formed separately in advance, and the lead pipe is inserted into the corrugated metal pipe later, thereby inserting the lead pipe into the corrugated metal pipe. A method for manufacturing a composite pipe according to item 1 or 2.