JP4039533B2 - Rust prevention tool for metal fluid pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, for example, when opening work for connecting a branch pipe or the like to a water pipe or gas pipe buried in the ground, or when a metal part that is easily rusted is exposed inside the pipe, etc. The present invention also relates to a rust preventive tool that can prevent rusting or corrosion at the exposed portion.
[0002]
[Prior art]
In general, taking the example of water supply, when water distribution work is already performed on water pipes already laid in the ground, etc., the water pipe is opened without stopping the water flow in the water pipe, and then branched. A continuous water method for connecting pipes and the like is used. In such a continuous water construction method, since it is impossible to apply a rust prevention treatment such as painting to the metal surface of the opening exposed by drilling, it is common to leave the opening in a perforated state. It is.
[0003]
As a result, the exposed metal surface of the opening may be rusted or corroded, causing deterioration of water quality.
[0004]
This is due to the action of the oxygen concentration cell due to the difference between the dissolved oxygen concentration in running water in the water pipe and the oxygen concentration of water in the soil, etc. A macro cell with a potential difference between the metal surface of the opening that is made into running water and the surface of the water pipe in contact with the soil, with the metal surface exposed by drilling being the anode part and the surface of the water pipe being the cathode part This is because a corrosion current flows from the metal surface.
[0005]
In order to solve the above problems, in recent years, a sleeve made of a synthetic resin and fitted with a sleeve made of a synthetic resin is provided on the inner surface of the opening after the opening is perforated.
[0006]
[Problems to be solved by the invention]
However, in the above-described rust prevention treatment with the sleeve, if the inner surface of the opening is not a smooth surface, a gap is formed between the outer peripheral surface of the sleeve, and water penetrates into this gap and the metal surface after drilling is formed. There is a risk of rusting.
[0007]
In addition, the operation of attaching the sleeve to the opening is troublesome, and a dedicated tool for attaching the sleeve is required, which increases the cost.
[0008]
The present invention was made in order to solve the above-mentioned problems, and rust and the like are generated in the exposed portion without subjecting the above-described opening or the exposed portion of the metal formed for some reason to special rust prevention treatment. An object of the present invention is to provide a rust preventive tool that can surely prevent the rusting.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the rust preventive tool of the present invention surrounds a metal exposed portion where a metal material of a metal fluid pipe is directly exposed to the fluid with a case, and rust-proofing the metal exposed portion . A rust preventive tool that has a larger ionization tendency than the metal constituting the fluid pipe, and
A metal having a smaller ionization tendency than the metal mass and a high potential metal, screwed into a screw cylinder provided in the case, and a fixing bolt whose tip is pressed against the outer peripheral surface of the fluid pipe; and a screw cylinder of the case An iron cap that is screwed to the outer peripheral surface of the open end of the metal plate to conceal the fixing bolt and has a flat surface in which a screw hole is formed at the top portion, and a metal with a high potential that is less ionized than the metal lump. A bolt to be screwed into the screw hole of the cap, one attachment portion fixedly connected to the metal block, and the other attachment portion fixedly connected to the flat portion of the cap by the bolt, the bolt And a conductive material that conducts between the bolt and the fixing bolt when the screw is screwed into the screw hole of the cap .
[0013]
It is preferable that the surface of the rust preventive tool is electrically shielded except for the metal block and the fluid pipe .
[0014]
The shield is preferably a film body formed by painting.
[0015]
According to the present invention, a dissimilar metal battery is formed using the metal mass as an anode and the metal exposed portion of the fluid tube as the cathode, and the metal mass is consumed as a sacrificial anode, and rust is generated in the metal exposed portion. Is prevented.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 shows a rust preventive tool 1 of the present invention, which is a rectangular plate made of zinc or a zinc alloy having a lower potential and a higher ionization tendency than ductile cast iron (or steel pipe) which is a material of a water main pipe 8 to be described later. A metal block 2 and a coated conductive wire 4 having ring-shaped mounting parts 3 and 3 at both ends, and one mounting part 3 is a bolt-shaped connection screwed to the top corner of the metal block 2 It is inserted into the terminal 5 and fixed by a nut 6.
[0018]
The mounting portion 3, the conductive wire 4, the connection terminal 5, and the nut 6 are made of a metal having a higher potential than the metal lump 2 and having a smaller ionization tendency, for example, a copper-based metal, in order to prevent them from being consumed. ing.
[0019]
The other attachment portion 3 of the conductive wire 4 is directly or indirectly connected to the vicinity of the opening 8a in the water main pipe 8 so as to be electrically conductive.
[0020]
Hereinafter, the connection example of the other attachment part 3 and the rust preventive action of the opening by the rust preventive tool 1 will be described.
[0021]
FIG. 2 shows the two openings exposed by cutting when the main valve 8 such as ductile cast iron embedded in the soil 7 is removed by cutting to a required length and then the gate valve device 9 is installed in an unreserved water state. The example of a connection in the case of carrying out rust prevention of the metal surface of the part 8a is shown.
[0022]
In addition, although installation of the said gate valve apparatus 9 is performed by the inserting method, since detailed description about this method is not directly related to this invention, it abbreviate | omits.
[0023]
In the case 10 attached to the outer peripheral surface of the water main pipe 8 so as to surround both openings 8a, the tips of the fixing bolts 12 screwed into a plurality of female screw cylinders 11 protruding from the outer peripheral surface are connected to the water main. It is fixed by being brought into pressure contact with the outer peripheral surface of the tube 8.
[0024]
Even when the outer peripheral surface of the water main pipe 8 is coated with rust prevention, the fixing bolt 12 strongly presses against the outer peripheral surface of the water main pipe 8, so that the coating film in that portion is peeled off, and the water main The pipe 8 and the fixing bolt 12 come into contact with each other.
[0025]
Reference numeral 13 denotes a special push ring with a detachment prevention fitting, which has a function of pressing the packing 22 to achieve water tightness and a function of preventing the water main pipe 8 from coming off.
[0026]
The other attachment portion 3 of the conductive wire 4 in the rust preventive tool 1 is connected to an iron cap 14 that is screwed onto the outer peripheral surface of the open end portion of the female screw cylinder 11 in order to conceal the fixing bolt 12.
[0027]
That is, as shown in an enlarged view in FIG. 3, a female screw hole 14 a is formed in the flat surface of the cap 14, and the bolt 15 is screwed into the cap 14 to fix the mounting portion 3 to the cap 14 and the fixing bolt 12. And the bolt 15 are electrically connected via the conductive material 40.
[0028]
The material of the fixing bolts 12 and 15 is preferably iron or the like having a lower ionization tendency and higher potential than the metal lump 2 in order to prevent wear. Further, if the entire surface is coated so that the cap 14, the attachment portion 3, the connection terminal 5, etc. are not directly exposed to the soil, the effect is further improved. In the following examples, it is effective to provide electrical insulation to the soil 7 except for the metal lump 2. A resin-based coating is effective as a shielding method.
[0029]
Thus, when the rust preventive tool 1 is connected to the cap 14, the metal lump 2 and the water main 8 are electrically connected, and the metal lump 2 is used as an anode and the opening 8 a of the water main 8 is used as a cathode. A dissimilar metal battery is formed.
[0030]
Therefore, when the excavated working pit is backfilled and the water main 8 and the rust preventive tool 1 are buried in the soil 7 as an electrolyte, a potential difference is generated between the metal lump 2 and the water main 8 and the anode side The metal lump 2 is dissolved in the soil 7 as zinc ions. As a result, only the metal lump 2 is consumed as a sacrificial anode, and the flow of electricity from the opening 8a is prevented, so that the oxygen concentration cell action between the running water in the water main 8 and the water in the soil 7 is prevented. Even if this occurs, rusting or corrosion of the metal surface of the opening 8a exposed by cutting is reduced.
[0031]
Since this rust prevention effect continues until the metal lump 2 is exhausted, the size of the metal lump 2 may be appropriately set according to the service life of the water main pipe 8 or the like.
[0032]
FIG. 4 is an enlarged view showing an example in which the rust preventive tool 1 is connected to the special push ring 13 instead of the cap 14.
[0033]
The special pusher wheel 13 is pressed toward the outer peripheral surface of the water main pipe 8 by a plurality of flanges 19 that can be fastened to the flange 16 on the case 10 side with a T-head mounting bolt 17 and a nut 18 and a plurality of push bolts 20. A sharp blade portion that can bite into the outer peripheral surface of the water main pipe 8 is formed at the tip of the bow-shaped claw 21.
[0034]
Reference numeral 22 denotes a packing that is pressed by the special pusher wheel 13 to maintain watertightness.
[0035]
The attachment portion 3 of the conductive wire 4 in the rust preventive tool 1 is connected to the push bolt 20 in a conductive state, and the push bolt 20 is brought into contact with the bow claw 21 in a conductive state. The sharp shape cuts into the water main 8.
[0036]
As described above, when the attachment portion 3 is fixed to the flange 19, the arcuate claw 21 peels off the rust preventive coating film of the water main 8 and comes into contact with each other, so that the metal lump 2 and the water main 8 Is electrically conductive through the special push wheel 13, and a dissimilar metal battery having the metal lump 2 as an anode and the opening 8a (see FIG. 2) of the water main pipe 8 as a cathode is formed as described above.
[0037]
Thereby, the metal lump 2 is consumed as a sacrificial anode, and the rust prevention action of the opening 8a occurs.
[0038]
The constituent member of the special push ring 13 is preferably made of a material having a smaller ionization tendency than the metal lump 2 in order to prevent its consumption.
[0039]
FIG. 5 shows the side wall of the water main 8 by a perforator inserted from the branch pipe portion 24 side after the split T-shaped pipe 23 is attached to the outer peripheral surface of the iron water main 8 embedded in soil (not shown). In the construction method in which a circular opening 8a is drilled and the running water in the water main pipe 8 is branched to the branch pipe 24 in an undisturbed state, the metal surface of the opening 8a exposed by drilling is removed by the rust preventive tool 1. An example of rust prevention is shown. 25 is a gate valve device.
[0040]
In this example, the connection portion 3 of the conductive wire 4 of the rust preventive tool 1 is made of metal on the right flange 23a by a part of T-head bolts 26 and nuts 27 that fasten the flanges 23a of the steel split T-tube 23. They are connected so that they touch each other.
[0041]
In addition, when the anti-corrosion coating is given to the split T-shaped tube 23, in order to improve the electrical continuity between the mounting portion 3 and the flange 23a, the contact surface of the flange 23a with the mounting portion 3 is improved. It is preferable to remove a part of the rust preventive coating film or to form a sharp protrusion on the contact surface of the mounting portion 3.
[0042]
Even when the outer peripheral surface of the water main 8 is coated with rust prevention, the inner surface of the split T-shaped pipe 23 on the side to which the mounting portion 3 is fixed and the outer peripheral surface of the water main 8 are made of metal. It is better to remove a part of the rust preventive coating on the contact surfaces so that they contact each other.
[0043]
When the rust preventive tool 1 is connected in this way, the metal lump 2 and the water main pipe 8 are electrically connected through the split T-shaped pipe 23, and the metal lump 2 serves as the anode and the opening of the water main pipe 8. A dissimilar metal battery having 8a as a cathode is formed.
[0044]
As a result, as described above, the metal lump 2 is consumed as a sacrificial anode, and rust is prevented from occurring in the opening 8a.
[0045]
In FIG. 6, a saddle 28 is attached to an iron water main pipe 8 embedded in soil (not shown), a circular opening 8 a is drilled on the upper surface of the pipe wall, and a water faucet 29 is formed above the saddle 28. In the construction method in which the rust preventive tool 1 is attached in an unreserved water state, an example is shown in which the metal surface of the opening 8a exposed by perforation is rusted by the rust preventive tool 1.
[0046]
In this example, the upper and lower flanges 28a are fixed by bolts 30 and nuts 31 for fastening the flanges 28a of the iron saddle 28 together. The saddle 28 is provided with a female threaded portion 51, to which the connecting portion 3 of the conductive wire 4 of the rust preventive tool 1 is fixed via a bolt 50, and the tip of the bolt 50 is brought into contact with the water main pipe 8 to be conductive. It is in a state.
[0047]
That is, even when the outer peripheral surface of the water main 8 is coated with rust prevention, the bolt 50 partially removes the coating film on the surface of the water main 8.
[0048]
When the rust preventive tool 1 is thus connected, the metal lump 2 and the water main 8 are electrically connected via the saddle 28, the metal lump 2 is the anode, and the opening 8a of the water main 8 is the cathode. Thus, a dissimilar metal battery is formed.
[0049]
As a result, as described above, the metal lump 2 is consumed as a sacrificial anode, and rust is prevented from occurring in the opening 8a.
[0050]
In this example as well, in order to prevent the bolts 30 and the nuts 31 from being consumed, it is preferable that these materials be metals having a smaller ionization tendency than the metal lump 2.
[0051]
FIG. 7 shows that an iron branch case 32 having a bifurcated structure 32a having a branch pipe portion 32a is attached to the outer peripheral surface of an iron water main pipe 8 embedded in soil (not shown) while maintaining watertightness. With the inserted drilling machine, an opening 8a having a C-shaped cross section is drilled in the side wall at a position eccentric from the center of the pipe axis of the water main pipe 8, and the running water in the water main pipe 8 is continuously fed to the branch pipe section 32a side. In the method of branching in a state, an example is shown in which the metal surface of the opening 8a exposed by drilling is rusted by the rust preventive tool 1 of another embodiment of the present invention. 33 is a gate valve device.
[0052]
In the rust preventive tool 1 of this embodiment, the conductive wire 4 as described above is omitted, and the metal lump 2 is directly fixed to the iron branch case 32 with a plurality of bolts 2a.
[0053]
By providing such a bolt 2a, the coating film of the water main 8 is cut off by 2a, so that a dissimilar metal battery having the metal lump 2 as an anode and the opening 8a of the water main 8 as a cathode is formed. . Thereby, like the above-mentioned, the metal lump 2 is consumed at the expense, and it is prevented that rust is generated in the opening 8a.
[0054]
As described above, the rust preventive tool 1 according to the present invention has the conductive wire 4 attached to the connection terminal 5 of the metal lump 2 made of zinc or the like as long as the water main and its accessories are already conductive. Connected to the accessory part of the case 10 to be mounted in contact with the main pipe 8, that is, the cap 14 or the special push ring 13, or the bolts 26, 30 and the nut 27, It is possible to reliably prevent the rust from being generated in the opening 8a simply by forming the dissimilar metal battery with the metal lump 2 as an anode and the opening of the water main pipe 8 as a cathode. .
[0055]
The present invention is not limited to the above embodiments.
[0056]
The connected part of the conductive wire 4 may be other than the cap 14 and the special push ring 13 as long as it is an attached part that is electrically connected to the water main pipe 8 on a split T-shaped pipe or the like.
[0057]
The fluid pipe to which the present invention is applied may be a fluid pipe laid so as to come into contact with an electrolyte medium such as concrete, seawater, groundwater, etc., outside the water main pipe 8 buried in the soil.
[0058]
Moreover, in addition to the rust prevention of the opening 8a drilled in the above-described continuous water construction method, it can be applied to rust prevention measures for the opening of other existing pipes that cannot be rust-prevented after drilling.
[0059]
The material of the metal lump 2 can be not only zinc or its alloy, but also aluminum or its alloy, magnesium or its alloy, or a combination of these three, etc. Any metal can be used.
[0060]
Needless to say, the shape of the metal lump 2 is not limited to that of the above embodiment.
[0061]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0062]
(A) The fixing bolt that is pressed against the outer peripheral surface of the fluid pipe without performing the troublesome work of attaching a rust prevention sleeve to the opening as in the prior art has a greater ionization tendency and lower By simply connecting the connection terminals of a potential metal lump, the metal lump and the exposed metal part of the metal fluid pipe are in a low resistance conduction state, and it is possible to reliably prevent rust from occurring in the opening. .
[0065]
(B) According to the invention described in claims 2 to 3 , electrons are effectively supplied only to the exposed metal portion, and the rust prevention effect is improved.
[0066]
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of a rust preventive tool according to the present invention.
FIG. 2 is a central longitudinal sectional side view of the rust preventive tool of the present invention applied when rusting an opening cut for installing a gate valve device.
3 is an enlarged cross-sectional view of a main part showing details of a connection example of the cap mounting portion and the metal block in FIG.
4 is an enlarged cross-sectional view of a main part showing a connection example of the special push ring and the metal block corresponding thereto in FIG.
FIG. 5 is a longitudinal front view showing an example in which a metal lump is connected to a bolt and nut for fastening a split T-shaped tube.
FIG. 6 is a longitudinal front view showing an example in which a metal lump is connected to a bolt and a nut for fastening a saddle.
FIG. 7 is a longitudinal front view showing an example in which a rust preventive tool according to another embodiment of the present invention is integrally fixed to a branch case.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rust prevention tool 2 Metal lump 2a, 5 Connection terminal 3 Connection part 4 Conductive wire 6 Nut 7 Soil 8 Water main (fluid pipe)
8a Opening (metal exposed part)
9 Gate valve device 10 Case 11 Female thread cylinder 12 Fixing bolt 13 Special push ring 14 Cap 14a Female thread hole 15 Bolt 16 Flange 17 T-head mounting bolt 18 Nut 19 Flange 20 Push bolt 21 Arch claw 22 Packing 23 Split T-shaped pipe 23a Flange 24 Branch pipe part 25 Gate valve device 26 T head bolt 27 Nut 28 Saddle 28a Flange 29 Water faucet 30 Bolt 31 Nut 32 Branch case 32a Branch pipe part 33 Gate valve device 40 Conducting material 50 Bolt 51 Female thread part

Claims (3)

The metal material of the metal fluid pipe is a rust preventive tool that surrounds a metal exposed part exposed directly in the fluid with a case, and rust-proofs the metal exposed part ,
A metal mass having a larger ionization tendency than the metal constituting the fluid pipe;
A metal having a smaller ionization tendency than the metal mass and a high potential metal, screwed into a screw cylinder provided in the case, and a fixing bolt whose tip is pressed against the outer peripheral surface of the fluid pipe;
An iron cap screwed to the outer peripheral surface of the open end of the screw cylinder of the case, concealing the fixing bolt, and having a flat surface in which a screw hole is formed in the top portion;
A metal having a smaller ionization tendency than the metal mass and a high potential, and a bolt screwed into the screw hole of the cap;
One mounting portion is fixedly connected to the metal block, and the other mounting portion is fixedly connected to the flat portion of the cap by the bolt, and a conductive wire,
A conductive material for conducting the bolt and the fixing bolt when the bolt is screwed into the screw hole of the cap;
Rust tool metal fluid tube, characterized in that it comprises a. The rust preventive tool for a metal fluid pipe according to claim 1, wherein the metal block and the surface of the fluid pipe are electrically shielded except in the fluid pipe. The rust preventive tool for a metal fluid pipe according to claim 2, wherein the shield is a film body formed by painting .

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