JP4855132B2 - Corrosion prevention method for metal pipe support and corrosion prevention composite used in the corrosion prevention method - Google Patents

Description

  The present invention relates to a corrosion prevention method in a support portion of a metal pipe and a corrosion prevention composite used in the corrosion prevention method. More specifically, the present invention relates to a metal pipe and support for transportation of fluids such as gas and oil. The present invention relates to a corrosion-preventing composite used in a method for preventing corrosion and wear that easily occurs at a contact portion with a mounting base and a method for preventing corrosion of metal pipes.

  Pipes for transport fluids are classified into overhead, ground, and underground buried pipes, but the most common are overhead pipes that are used to continuously transport fluids containing gas or oil. Various metal pipes constituting the line are usually fixed on a support frame.

Metal pipes are generally made of a metal such as carbon steel, but it has long been known that corrosion and wear occur in the pipes in contact with the support frame on which the pipes are installed.
Such a phenomenon is due to the piping expanding and contracting due to a change in temperature, and the piping being scraped and worn by sliding at the contact portion with the gantry.
In addition, when vibration occurs in the pipe due to the influence of the pulsation of the transport fluid inside the pipe, wear similarly occurs.

Furthermore, since a narrow gap occurs in a relatively wide range at the contact portion between the pipe and the gantry, dust, rainwater, etc. infiltrate and stay as a result, the pipe often rusts, and if the pipe is perforated, It may also cause a serious accident that the contents leak.
Therefore, various proposals have conventionally been made as measures for preventing corrosion and wear of pipes supported by aerial, and they have already been put into practice.

For example, according to Prior Art 1 (Japanese Patent Laid-Open No. 63-44828 (hereinafter referred to as “Patent Document 1”)), a member made of zinc or a zinc alloy is interposed between a pipe and a support base. Corrosion prevention methods for supporting parts of metal pipes have been proposed.
According to such a proposal, the zinc or zinc alloy interposed between the pipe and the support frame is selected as a material having a sacrificial anode effect on the steel pipe or iron pipe, and the zinc or zinc alloy It is described that the electric potential is always lower than the pipe made of iron pipe, and thus a galvanic circuit is formed between the pipe and the steel pipe or iron pipe, thereby effectively preventing corrosion of the pipe.

  According to Prior Art 2 (Japanese Patent Laid-Open No. 9-242882 (hereinafter referred to as “Patent Document 2”)), a pressure-sensitive adhesive layer, a zinc plate, and a resin that contain zinc powder and can be imparted with conductivity when pressed. An anticorrosion method for a pipe is disclosed in which a pipe in which an anticorrosion member having a layer structure of a film and a stainless steel plate is in close contact is placed on a gantry.

  Further, in Prior Art 3 (Japanese Patent Laid-Open No. 10-306388 (hereinafter referred to as “Patent Document 3”)), a corrosion prevention method by interposing a magnesium alloy thin plate as a sacrificial anode metal at a contact portion between a pipe and a support frame. Is disclosed.

  However, it has been pointed out that the anticorrosion method described in Patent Document 1 has a large load due to piping, and the zinc plate may cause fatigue corrosion cracking, and further white rust is generated on the outside air side, which is undesirable from the appearance. In addition, if the piping is at a high temperature as in the case of transporting heavy petroleum oil products, there is a possibility that the adverse effect may occur and the piping may be corroded and cannot be used. In the method described in Patent Document 2, depending on the life of the adhesive, it may be peeled off in a short period of time and may not exhibit a sufficient anticorrosive effect. In addition, in order to securely fix the anticorrosive material, it is necessary to adjust the base material of the piping, and the workability is low and the construction cost is also high, so it is difficult to determine the life of the anticorrosive material In order to inspect the corrosion state, it is necessary to remove the anticorrosive material from the pipe, and maintenance problems are also included.

  Furthermore, in the anticorrosion method by patent document 3, although the magnesium alloy anticorrosion board as a sacrificial anode metal is being fixed using a fixed band (U bolt), when piping moves by thermal expansion or a fixed band loosens There is a risk that the anticorrosion plate may fall, and there are points to be improved in practice, such as frequent maintenance and inspection. In addition, in such an anticorrosion method, a magnesium alloy proposed as a sacrificial anode metal has been pointed out to be problematic in terms of work, such as being difficult to process, expensive and not easily available.

As described above, conventionally proposed methods for preventing corrosion of metal pipes include methods using electro-corrosion, but none of them can sufficiently secure the corrosion life of metal pipes, and continuous inspection is frequently performed. Therefore, there are many points that need to be improved for practical use in order to achieve a long-term stable corrosion and wear prevention effect. Under such circumstances, there has been a strong demand for the development of an inexpensive and long-term maintenance-free anticorrosion method that can ensure the fundamental anticorrosion performance and wear prevention performance of metal pipes.
JP-A 63-44828 Japanese Patent Laid-Open No. 9-242982 JP-A-10-306388

  Accordingly, the object of the present invention is to prevent the occurrence and progression of corrosion and wear occurring at the support portion of the metal pipe, particularly at the contact portion with the support base, in view of the conventional development situation concerning the corrosion prevention of the metal pipe as described above. The purpose is to prevent and extend the life of metal pipes.

  It is another object of the present invention to provide a corrosion prevention method that is technically and economically useful in repairing corrosion and wear occurring in existing metal pipes.

  Therefore, as a result of intensive studies in order to solve the above-described problems of the present invention, the present inventor requires special work in the case of newly installing a metal pipe and repairing an existing metal pipe. As a possible corrosion prevention method at a low cost, the contact portion between the pipe and the support gantry includes (a) a rod-like support member, and (b) a form surrounding the rod-like support member. Corrosion-preventing composite consisting of half-divided pipe made of metal which is a base metal and having anti-corrosive effect on different metals, or a structure for corrosion prevention comprising a base metal rod-like support member for the metal pipe Focusing on the fact that problems that have been pointed out in the past can be solved by interposing the body, the present invention has been conceived and completed based on such knowledge.

Thus, according to the present invention,
A method for preventing corrosion of a metal pipe supported by a support frame,
In the contact portion between the metal pipe and the support frame,
(A) a rod-like support member;
(B) a corrosion-preventing composite comprising a base metal half tubular covering member surrounded by the rod-shaped support member and surrounded by the base metal pipe;
There is provided a method for preventing corrosion at a support portion of a metal pipe, wherein the metal pipe is inserted so as to intersect with a pipe axis direction of the metal pipe.

Also, a method for preventing corrosion of a metal pipe supported by a support frame,
In the contact portion between the metal pipe and the support frame,
A structure for preventing corrosion comprising a base metal rod-like support member for the metal pipe,
There is provided a method for preventing corrosion at a support portion of a metal pipe, wherein the metal pipe is inserted so as to intersect with a pipe axis direction of the metal pipe.

Furthermore, according to the present invention,
A composite for preventing corrosion used in a method for preventing corrosion in a support part of a metal pipe,
1) a rod-like support member;
2) A metal pipe corrosion-preventing composite comprising a half tubular covering member made of a base metal with respect to the metal pipe and surrounding the rod-like support member is provided. The

As described above, the present invention is a method for preventing corrosion at a contact portion of a metal pipe supported by a support frame,
Corrosion prevention method for corrosion prevention in metal pipe supporting part for interposing said corrosion prevention composite or said corrosion prevention structure in contact part between said metal pipe and said support gantry, and said corrosion prevention method (I) the corrosion-preventing structure comprises a base metal rod-like support member for the metal pipe, and (ii) the corrosion-preventing composite is
a) a rod-like support member;
b) It is disclosed that it is a combination with a half tubular covering member made of a base metal with respect to the metal pipe surrounded by the rod-like support member. ) To 11) are included.

1) The corrosion prevention method in the support part of the said metal piping whose said metal piping is carbon steel piping.
2) The corrosion prevention method in the support part of the said metal piping whose base metal with respect to the said metal piping is aluminum or aluminum alloy.
3) A method for preventing corrosion in the support portion of the metal pipe, wherein the shape of the longitudinal cross section of the rod-like support member of the structure for preventing corrosion is circular or elliptical.
4) A method for preventing corrosion at a support portion of the metal pipe, wherein the half-shaped tubular covering member of the composite for corrosion prevention has a circular or elliptical cross-sectional shape.
5) A method for preventing corrosion at a support portion of the metal pipe, wherein the material of the rod-like support member and the half tubular covering member of the corrosion prevention structure is a soft metal with respect to the metal pipe.
6) A method for preventing corrosion at a support portion of the metal pipe, wherein the rod-shaped support member of the structure for preventing corrosion is aluminum or an aluminum alloy.
7) A method for preventing corrosion at a support portion of the metal pipe, wherein the material of the half tubular covering member of the composite for corrosion prevention is aluminum or an aluminum alloy.
8) A method for preventing corrosion at a support portion of the metal pipe, wherein the means for fixing the half tubular covering member to the support base is a bracket structure.
9) A method for preventing corrosion at a support portion of the metal pipe, wherein the bracket is made of aluminum or an aluminum alloy.
10) A method for preventing corrosion of metal pipes supported by a support frame,
In the contact portion between the metal pipe and the support frame,
(A) a rod-like support member;
(B) Half of base metal with respect to the metal pipe surrounded by the rod-shaped support member
A tubular covering member;
(C) The (a) rod-shaped support member and the (b) half tubular covering portion are fixed to the support frame.
A metal pipe comprising a rod-shaped support member and a half tubular covering member which are inserted so that the rod-shaped support member and the half tubular covering member intersect the tube axis direction of the metal pipe. Corrosion prevention method for support.
11) A method for preventing corrosion of metal pipes supported by a supporting stand,
(A) a base metal support member for the metal pipe;
(B) Inserting a corrosion-preventing structure comprising a bracket for fixing the rod-shaped support member to the support frame so that the rod-shaped support member intersects the tube axis direction of the metal pipe. The corrosion prevention method in the support part of the metal piping which consists of.

1. Since the longitudinal sectional shape of the half tubular covering member constituting the corrosion preventing composite according to the present invention is circular or elliptical, the contact with the metal pipe is a point contact, and the contact area is minimized. Intrusion and retention of water, dust and the like can be prevented, and corrosion and wear of the metal pipe can be minimized.

2. Moreover, since the longitudinal cross-sectional shape of the rod-shaped support body of the structure for corrosion prevention according to the present invention is circular or elliptical, it is point contact with the metal pipe, and the material of the rod-shaped support body is relative to the metal pipe. Since the metal is soft and used for the metal pipe, corrosion and wear of the metal pipe can be minimized.
The fixing means for the rod-like support is a blanket, is excellent in workability such as being able to be firmly fixed by a simple operation, and does not require welding with a gantry, which is advantageous in terms of economy.

3. The composite for corrosion prevention according to the present invention is:
a) a rod-shaped support member, and b) a half-tube-shaped covering member made of a base metal with respect to the metal pipe, which is provided so as to be surrounded by the rod-shaped support member. It is possible to remarkably improve the anticorrosion effect and corrosion life due to only the support member, and to remarkably improve the strength shortage of bending and dropping due to the weight of the metal pipe when only the half tubular covering member is used.
Moreover, since it can be installed on the support frame without requiring welding, the economic effect is extremely large.
Furthermore, the composite for corrosion prevention is particularly useful in terms of material and work in the repair of existing pipes, and has excellent support strength stability compared to a corrosion prevention structure made of an aluminum rod-shaped support. .

4). Since a base metal is used for the metal pipe as the material of the half tubular covering member, the half tubular covering member has a sacrificial anode effect, and the potential is always base for the metal pipe. Therefore, it is possible to effectively prevent corrosion of metal pipes by using the current generated with melting. In particular, the metal pipe and the half tubular covering member are in point contact, but if a small amount of water is present, the anticorrosion can be effectively performed.

5. The aluminum of the half tubular covering member according to the present invention is softer than the carbon steel of the pipe, and the pipe is hardly contacted with the half tubular covering member and wear hardly occurs. There is an effect.

6). Fixing of the half tubular covering member and the support frame by the bracket can be performed by a simple operation only by bending.

7). According to the present invention, for the inspection of the corrosion prevention status of the pipe, the contact portion between the pipe and the half tubular covering member does not need to be disassembled and can be directly observed in appearance, so that the operation is simple and low cost. , Maintenance can be performed efficiently.

8). Furthermore, as shown also in the below-mentioned Examples, when the metal pipe is carbon steel and the half tubular covering member is aluminum, it has a service life of 10 years or more, and prevents corrosion of the maintenance-free metal pipe. A method can be provided. Aluminum materials also have the practical advantage of being much easier to obtain than magnesium and the like.

9. According to the present invention, the contact between the metal pipe and the half tubular covering member in the corrosion prevention method in the support portion of the metal pipe is due to point contact, and the structure of the point contact is the surface contact according to the above prior art. Compared with corrosion in this case, since retention of moisture and the like can be prevented, there is a merit that it is easy to inspect and inspect the state of corrosion in addition to having a remarkable corrosion prevention effect.

  According to the corrosion prevention method in the support part of the metal pipe according to the present invention, the contact part between the metal pipe and the support cradle includes (a) a bar-like support member and (b) surrounding the bar-like support member. The corrosion prevention is performed by interposing a corrosion prevention composite comprising a half-shaped tubular covering member having a circular or elliptical longitudinal section and (c) a fixing means having a bracket structure. Points that minimize the contact area with steel pipes, and that the effect of dissimilar metal corrosion is applied to electrically prevent general pipes such as carbon steel from being electrically protected. In addition, a bracket structure is employed to prevent the split tubular covering member from dropping due to expansion and contraction of the pipe and vibration.

  Further, according to the present invention, at the contact portion between the metal pipe and the support pedestal, (a) a base metal rod-shaped support member with respect to the metal pipe, and (b) the bar-shaped support member is supported. The corrosion prevention of the metal pipe is carried out by interposing a corrosion prevention structure comprising a fixing means comprising a bracket structure for fixing to the gantry. The metal pipe and the rod-like support member can be point-contacted to minimize the contact area and apply the effect of dissimilar metal corrosion to electrically prevent carbon steel and the like. In particular, the corrosion prevention method using the corrosion prevention structure has a simple configuration in the case of newly installing piping, and can be applied efficiently.

A suitable metal pipe applied in the method for preventing corrosion of a metal pipe targeted by the present invention is not particularly limited as long as it is of a material and form capable of transporting petroleum products and the like ranging from a low temperature to a high temperature. It may be either steel or non-ferrous metal, and examples of steel include carbon steel, low alloy steel, and high alloy steel. The low alloy steel has an alloy content of 10% or less, and can include Cr—Mo alloy steel, Ni alloy steel, etc., and high alloy steel such as Cr—Ni alloy steel. Carbon steel is preferred for the implementation of the prevention method.
Moreover, things, such as 4B pipe-20B pipe, are mentioned as a pipe diameter, It does not specifically limit.

  The piping installation method generally includes aerial, ground, and underground underground piping, but the corrosion prevention method for the metal pipe support according to the present invention is particularly useful for preventing corrosion of the aerial piping.

  The support frame is not particularly limited, and a commonly used one can be used, and one made of steel can be used. Specifically, H steel or the like is usually used. As shown in FIG. 8, the support pedestals are installed at regular intervals in oil storage tank yards, shipping facilities, etc., and the pipes are installed in the air.

Rod-like rod-like support member constituting the corrosion prevention structure according to the support member present invention is made of a base metal to the metallic pipe as indicated by the round bar 1 'in FIGS. 5 and 6. Examples of the base metal include aluminum and aluminum alloys, zinc and zinc alloys, magnesium and magnesium alloys, etc., and aluminum and aluminum alloys are particularly suitable (hereinafter referred to as the structure for corrosion prevention in the present specification). When displaying the bar-shaped support member, it may be referred to as “aluminum bar-shaped support member” for convenience.)

  The aluminum rod-like support member preferably has a circular or oval longitudinal cross-sectional shape so as to be in point contact with the pipe.

  The size of the aluminum rod-shaped support member is 1 to 50 mm, preferably 10 to 20 mm in diameter when the diameter of the pipe is 2 to 32 inches, and the length is 0.5 to 1 of the pipe diameter. When multiple pipes are laid 5 times or on the same frame, one corresponding to the total length of the frame is preferable.

  On the other hand, the rod-like support member constituting the corrosion-preventing composite is equivalent to the component (a) of the corrosion-preventing composite according to the present invention, as specifically shown by the round bar 1 in FIGS. To do.

  The shape of the longitudinal cross section of the rod-shaped support member is not particularly limited, but the half tubular covering member surrounded by the rod-shaped support member has a circular cross section in order to achieve point contact with the metal pipe. In view of the strength of the corrosion prevention composite, it is preferable to match the shape of the inner surface of the half tubular covering member. In addition, the material of the rod-like support member is not limited, and steel such as steel and stainless steel is used, but a base metal is selected for the pipe because of contact with the half tubular covering member. Is preferred.

  Furthermore, in the corrosion-preventing composite, the size of the rod-like support member is preferably selected so that it can be fitted inside the half-shaped tubular covering member so that it can be supported. Therefore, when the diameter of the metal pipe is 2 to 32 inches and the shape of the longitudinal section of the rod-shaped support member is circular, the diameter of 5 to 50 mm is preferable. Moreover, what is necessary is just to make the length of a rod-shaped supporting member correspond to the length of a half tubular covering material as mentioned later.

The half tubular covering member The half tubular covering member is exemplified by the aluminum wear ring cover half pipe 2 (hereinafter, referred to as “aluminum half pipe” in the present specification unless otherwise specified). Thus, it has a half tubular shape surrounding the rod-shaped support member, and corresponds to the component (b) of the corrosion-preventing composite according to the present invention. The shape of the longitudinal section of the half tubular covering member is not particularly limited, but a semicircular shape or a semi-elliptical shape is preferable. In such a shape, the metal pipe is in point contact, and the contact area is minimized. The curvature of the half pipe is controlled so that

  In other words, if the contact portion of the half pipe becomes a projection shape, the wear of the pipe is promoted conversely, and if the contact portion is in a horizontal state, moisture and dust are likely to stay and induce corrosion. Since adverse effects occur, it is important that the contact portion of the half pipe with the piping has a longitudinal cross section, that is, a cross section of the half pipe shown by the aa ′ cross section in FIG.

  Moreover, a base metal is selected for the material of the half tubular covering member with respect to the metal pipe. Examples of base metals for steel include aluminum, aluminum alloys, zinc, zinc alloys, magnesium, and magnesium alloys. Since metal pipes are usually made of carbon steel, these metals, particularly aluminum or aluminum alloys, are excellent in workability and economy, as base metals for half tubular covering members, It is particularly preferable because it is easily available.

  Such an aluminum or aluminum alloy has a base potential that is always lower than that of the steel pipe and has an effective sacrificial anode effect, so that corrosion of the pipe can be effectively prevented by corrosion of the aluminum of the half tubular covering member.

  Since the half tubular covering member is in contact with the metal pipe by point contact at the support portion, moisture and dust are prevented from entering and staying at the support portion, and corrosion caused by these is effectively prevented. The

  In addition, the size of the half tubular covering member is selected so that the contact with the metal pipe is a point contact, and when the diameter of the metal pipe is 2 to 32 inches, the half tubular covering member Is determined in the range of 5 to 50 mm + thickness of the half tubular covering member, preferably 10 to 20 mm + thickness of the half tubular covering member. Further, the length of the half tubular covering member is not limited and can be arbitrarily selected. However, the pipe diameter is 0.5 to 1.5 times the pipe diameter or a plurality of pipes are laid on the same frame. If it is, the one corresponding to the total length of the gantry is preferable.

Corrosion-preventing structure and means for fixing the corrosion-preventing complex The means for fixing the corrosion-preventing structure and the corrosion-preventing composite according to the present invention to the supporting frame is indicated by reference numeral 4 in FIGS. As described above, a soft metal strip member that can be freely deformed is used. That is, the corrosion prevention structure includes (a) an aluminum rod-like support member and (b) a bracket structure for fixing the aluminum rod-like support member on the support frame. One end of the fixing means is joined to the aluminum bar-like member by welding or the like, and the other end is bent along the end of the gantry to fix the bar-like support member on the gantry.

  In the composite for preventing corrosion, the fixing means is used for fixing (a) the rod-like support member and (b) the half tubular covering member on the support frame. Usually, specifically, a bracket structure is preferable. One end of the fixing means is joined to the half tubular covering member by welding, and the other end is fixed to the gantry by bending. The material of the fixing means is not particularly limited, but an aluminum material is suitable from the viewpoints of weldability with the half tubular covering member, avoidance of damage due to dissimilar gold corrosion, ease of bending, and the like.

Further, the fixing means can easily prevent deformation of the half tubular covering member due to its own weight, in addition to preventing the half tubular covering member from dropping due to expansion and contraction of the pipe and vibration.
Hereinafter, the present invention will be described more specifically with reference to the drawings.

FIG. 1 is a plan view showing a state in which a corrosion-preventing complex used in the method for preventing corrosion of metal pipes according to the present invention is installed on a support frame 3. In the figure, 1 ... a round bar made of carbon steel, 2 ... an aluminum half pipe, 3 ... a frame, 4 ... a bracket and 5 ... a welded part are shown.
FIG. 1 shows a structure in which a round bar 1 constituting a corrosion preventing composite according to the present invention and an aluminum half pipe 2 surrounding the round bar 1 are fixed on a support base 3 by a bracket 4. ing. The bracket 4 is joined to the aluminum half pipe 2 by welding 5, and is fixed to the gantry 3 by bending the other end.

  FIG. 2 is an explanatory view showing a state in which a corrosion-preventing composite is inserted in the contact portion between the support base 3 and the metal pipe 6. In the figure, in the same manner as in FIG. 1, 1 ... round bar, 2 ... aluminum half pipe, 3 ... mount, 4 ... in addition to bracket, 6 ... pipe is shown. A portion indicated by a symbol A is a point contact portion between the pipe 6 and the aluminum half pipe 2. As shown in FIG. 7, the corrosion-preventing composite is arranged so as to cross the pipe axis direction of the pipe 6, that is, in a sleeper shape.

  FIG. 3 is a cross-sectional view taken along the line aa ′ of FIG. 1 and shows the cross-sectional structure of the corrosion-preventing composite according to the present invention. In the figure, the carbon steel round bar 1 surrounds the round bar 1. The aluminum half pipe 2, the supporting frame 3, and the bracket 4 are shown. The combination of the round bar 1, the aluminum half pipe 2 and the bracket 4 constitutes a corrosion prevention composite B. The aluminum half pipe 2 is joined to the bracket 4 by a welded portion 5. The other end is bent along the end of the gantry 3, and the corrosion-preventing composite B is fixed to the gantry 3 by the bracket 4. The support frame 3 is made of H steel.

  FIG. 4 is a partially enlarged perspective view of the composite B for corrosion prevention according to the present invention. An aluminum half pipe 2 surrounding a carbon steel round bar 1 is shown.

FIG. 5 is a plan view showing a state in which the structure for preventing corrosion used in the method for preventing corrosion of metal pipes according to the present invention is installed on the support frame 3. In the figure, 1 '... aluminum round bar, 3 ... gantry, 4 ... bracket and 5 ... weld are shown.
According to FIG. 5, an aluminum round bar 1 ′ is arranged in a direction perpendicular to the pipe axis direction of the pipe 6, and the pipe 6 is placed on the aluminum round bar 1 ′ arranged in a sleeper shape.

  FIG. 6 is a cross-sectional view taken along the line a-a ′ of FIG. 5 and shows a state in which the aluminum round bar 1 ′ is fixed on the pedestal by a bracket.

  FIG. 7 is a plan view showing an implementation status of the corrosion prevention method in the support portion of the metal pipe according to the present invention. According to the figure, a state where the pipe 6 is placed on the corrosion-preventing composite is shown. The aluminum half pipe 2 is arranged on the mount 3 in a direction perpendicular to the pipe axis direction of the pipe 6, and the pipe 6 is placed on the aluminum half pipe 2 arranged in a sleeper shape.

  FIG. 8 is a schematic diagram of an aerial pipe showing a state of application of a corrosion prevention method in a support part of a metal pipe according to the present invention to a pipeline for transporting petroleum products or the like. The interval between the corrosion-preventing composites is not particularly limited, and is arbitrarily determined depending on the size of the pipe diameter. According to the figure, a metal pipe 6 is mounted on a gantry 3 on a corrosion-preventing composite comprising a carbon steel round bar 1, an aluminum half pipe 2, and a blanket 4 to which these are fixed. Such corrosion-preventing composites are installed at arbitrary intervals.

  FIG. 9 illustrates the contents of Comparative Example 1 as the prior art for the present invention, and shows a state in which the pipe 6 is directly placed on the carbon steel round bar 1. A ′ is a contact portion between the pipe and the carbon steel round bar 1. In addition, the conventional carbon steel round bar 1 is fixed on the pedestal by welding 5.

  FIG. 10 shows the anticorrosion method described in Patent Document 2 listed as an example of the prior art. In the figure, reference numeral 13 denotes an adhesive layer containing zinc powder, which shows a fluid anode method with a sacrificial anode metal interposed, but it is possible to avoid corrosion due to mixing and retention of rainwater, dust, etc. with the anticorrosive member. In addition, there is a problem that the anticorrosion effect cannot be inspected unless the adhesive layer attached to the pipe is peeled off, which requires a huge amount of work.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to such examples.

[Examples 1 to 6]
(1) Manufacture of composite for corrosion prevention The carbon steel round bar with an outer diameter of 12.5 mm on the H steel support base and the outer diameter of 1 inch enclosed and enclosed on the round bar, the thickness of the contact portion with the pipe A composite for preventing corrosion was produced by combining 3.0 mm aluminum halves. The composite for corrosion prevention was installed on an H steel frame and fixed with a bracket as shown in FIG.
Place the following metal pipes on the aluminum half pipe of the composite for corrosion prevention, and measure the remaining thickness of the aluminum half pipe and visually inspect the bracket as detailed below. The corrosion and wear state at the contact part with the aluminum half pipe was evaluated.
Metal pipes were tested for several different types of transport oil types such as carbon steel 10B pipe, 8B pipe, 4B pipe, etc., without changing or moving aluminum half pipes at approximately 31 locations. The amount of remaining aluminum half pipe was measured in October 2000 at the start and in September 2004, four years later. The amount of remaining meat was determined by measuring the distance between the lowermost surface of the pipe and the upper surface of the support base (mm)...

(2) Evaluation method a. Experiment contents 1. Experiment period 4 years
・ Experiment started October 2000
・ End of experiment September 2004 2. experimental method
A) Measurement of remaining amount of aluminum half pipe in contact with piping
B) Visual inspection of brackets Number of experiments 181 (from 10B to 31 locations, from 8B to 150 locations)
B. Experimental Results The annual wear rate was determined from the average remaining thickness measurement results at two locations at each contact area, and the expected life and corrected life were calculated. These measurement results are shown in Tables 1 and 2, including the results of visual inspection of the brackets.

注１）配管のカッコ内のＡ〜Ｆの表示は輸送油種を示す。Ａ〜Ｃは重質油であり、配管は、高温となる。Ｄ〜Ｆは軽質油であり、低温で輸送されるという条件下にある。
注２）年摩耗率の算出方法;
次の式により求める。

Note 1) A to F in the parentheses of piping indicate the type of transport oil. AC is heavy oil, and piping becomes high temperature. D to F are light oils and are in a condition of being transported at a low temperature.
Note 2) Annual wear rate calculation method;
Obtained by the following formula.

ここで、
ｔ ：アルミウェアリングカバー半割管の配管接触部の摩耗量（ｍｍ）
Ｙγ：アルミウェアリングカバー半割管の使用年数
注３）補正寿命の算出方法;
年摩耗率に基き、アルミウェアリングカバー半割管の肉厚が０ｍｍになる予想寿命を算出し、その結果が一般的な装置設計の指標となる２０年を超えた場合は寿命を２０年に切り下げ補正する。

here,
t: Wear amount (mm) of the pipe contact portion of the aluminum wear ring cover half pipe
Yγ: Service life of aluminum wear ring cover half pipe Note 3) Method for calculating the corrected life;
Based on the annual wear rate, the expected life when the thickness of the aluminum wear ring cover half pipe is 0 mm is calculated, and if the result exceeds 20 years, which is a general index for equipment design, the life will be 20 years. Correct the devaluation.

Comparative Example 1
As shown in FIG. 7, only a carbon steel round bar was used and an experiment was conducted in the same manner as in Example 1. As a result, the pipe had a maximum wear rate of 0.3 mm / year at the contact portion with the round bar. Meat was produced.

Comparative Example 2
When only a half pipe of an aluminum wear ring cover is used without using a round bar, the aluminum wear ring cover half pipe deforms due to warping due to the weight of the pipe, making visual inspections such as wear and corrosion difficult by visual inspection. It became. In addition, some of the half pipes dropped from the gantry under the external force of expansion and expansion of the pipe.

(3) Evaluation Results The following matters were found from the measurement results shown in Tables 1 and 2 as described above.
1) According to the prior art (Comparative Example 1), carbon steel piping is the largest
However, corrosion and wear occurred at an annual wear rate of 0.3 mm / year.
And according to Examples 1-6, the aluminum wear ring cover
Almost no corrosion or wear at the contact part with the half pipe
It was.
2) The bracket was securely fixed and never detached.
3) Aluminum wear ring cover half pipe depends on the weight of the pipe
There was no deformation such as warping, and sufficient practicality was ensured.
4) Aluminum wear ring cover half of the contact area with the support base
For wear resistance performance of the pipe, if the pipe is 8B or less,
Can be used continuously without maintenance for over 10 years
It was confirmed that

It is a top view which illustrates the corrosion prevention complex concerning the present invention. It is explanatory drawing which illustrates the case where the corrosion prevention method using the corrosion prevention composite_body | complex which concerns on this invention is implemented. It is sectional drawing of a-a 'of FIG. It is a partial expansion perspective view of the complex for corrosion prevention concerning the present invention. It is a top view which illustrates the structure for corrosion prevention which consists of an aluminum rod-shaped support member concerning the present invention. It is sectional drawing of a-a 'of FIG. It is a top view which illustrates the case where the corrosion prevention method using the composite for corrosion prevention which concerns on this invention is implemented. It is a schematic diagram of the aerial piping which shows the application condition to the pipeline of the corrosion prevention method in the support part of the metal piping which concerns on this invention. It is explanatory drawing which illustrates the case where the corrosion prevention method of metal piping using a carbon steel round bar is implemented. 6 is an explanatory diagram illustrating a pipe pedestal described in Patent Document 2. FIG.

Explanation of symbols

1-9
DESCRIPTION OF SYMBOLS 1 Carbon steel round bar 1 'Aluminum round bar 2 Aluminum half pipe 3 Base 4 Bracket 5 Welded part 6 Carbon steel piping A Base contact part A' Base contact part B Corrosion prevention composite
FIG.
11 Piping 12 Base 13 Corrosion protection plate 14 Mounting band

Claims (10)

A method for preventing corrosion of a metal pipe supported by a support frame,
In the contact portion between the metal pipe and the support frame,
(A) a rod-like support member;
(B) a corrosion-preventing composite comprising a base metal half tubular covering member surrounded by the rod-shaped support member and surrounded by the base metal pipe;
A method for preventing corrosion at a support portion of a metal pipe, wherein the metal pipe is inserted so as to intersect with a pipe axis direction of the metal pipe. A method for preventing corrosion of a metal pipe supported by a support frame,
In the contact portion between the metal pipe and the support frame,
A structure for preventing corrosion comprising a base metal rod-like support member for the metal pipe,
A method for preventing corrosion at a support portion of a metal pipe, wherein the metal pipe is inserted so as to intersect with a pipe axis direction of the metal pipe.   The method for preventing corrosion at a support portion of a metal pipe according to any one of claims 1 and 2, wherein the base metal for the metal pipe is aluminum or an aluminum alloy. The method for preventing corrosion in a support portion of a metal pipe according to claim 1, wherein a shape of a longitudinal section of the half tubular covering member of the composite for corrosion prevention is a shape that can be point-contacted with the metal pipe. The method for preventing corrosion at a support portion of a metal pipe according to claim 2, wherein a shape of a longitudinal section of the rod-shaped support member of the structure for corrosion prevention is a shape that can be in point contact with the metal pipe.   The method for preventing corrosion in a support portion of a metal pipe according to claim 1, wherein the means for fixing the half tubular covering member of the composite for corrosion prevention to the support base is a bracket structure. The method for preventing corrosion at a support portion of a metal pipe according to claim 2, wherein the means for fixing the rod-like support member of the corrosion prevention structure to the support base is a bracket structure. A corrosion-preventing composite used in the method for preventing corrosion of a metal pipe supported by a support base, in the support part of the metal pipe ,
1) a rod-like support member;
2) A half tubular covering member made of aluminum, aluminum alloy, zinc, zinc alloy, magnesium, or magnesium alloy surrounding the rod-shaped support member;
3) A metal pipe corrosion prevention composite comprising the bracket for fixing the 1) rod-like support member and the 2) half tubular covering member to the support frame. A corrosion prevention structure used in a method for preventing corrosion of a metal pipe in a support part of a metal pipe supported by a support frame,
(A) a rod-like support member made of aluminum, aluminum alloy, zinc, zinc alloy, magnesium, or magnesium alloy ;
(B) (a) a bracket for fixing the rod-like support member to the support base;
A structure for preventing corrosion of metal pipes, characterized by comprising: The composite for corrosion prevention of metal piping according to claim 8 or 9 , wherein a material of the bracket is aluminum or an aluminum alloy.

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