JPS62161972A - Attaching method for galvanic anode for preventing electric corrosion - Google Patents

Abstract

PURPOSE:To easily and surely attach the titled anode, by providing plural ends of terminals attached to structural material on surface of a coating material and connecting a suitable end with a galvanic anode after construction of structure. CONSTITUTION:The terminals 3 providing plural insulatedly covered lead wires 3a are attached to a sea bottom pipe 1 at a fixed interval prior to construction. The wire 3a is introduced to surface of the coating material 2 through a space between arranged ribs 6 of the material 2 such as concrete. Next, the terminals 7 are provided to top end of the wires 3a respectively, and the terminals 7 are thinly covered with the material 2. After layering the pipe 1 of the construction to a prescribed sea bottom, one of plural ends of each terminal 3 are exposed by scraping the material 2 and connected to the titled anode 4 through a lead wire 4a.

Description

[Detailed Description of the Invention] [Industrial Application] The present invention relates to a galvanic anode for cathodic protection of submarine pipes, steel pipe piles, etc., and in particular, a method for installing a galvanic anode for cathodic protection of submarine pipes and submarine pipes. It is related to.

[Conventional technology]

Conventionally, the following methods have been generally used to attach galvanic anodes for cathodic protection to rolled structures made of concrete, mortar, etc., such as submarine pipes and submarine pipes.

(1) As shown in FIG. 2, after laying the submarine pipe 1, attach the terminal 3 to an appropriate location on land, raise the lead 1j4a, and connect it to the galvanic anode 4. In the figure, 2 indicates a coating made of concrete or mortar, and 5 indicates the sea surface.

(2) As shown in Fig. 3, a method of directly welding a galvanic anode 4 having a thickness equivalent to the thickness of the concrete 1 or mortar coating 2 to the seabed g1 before laying the submarine pipe 1 ( bracelet method).

In the figure, bar 6 shows reinforcement embedded within the coating 2.

(3) As shown in FIG. 4, after laying the submarine pipe 1, terminals 3 are welded at regular intervals along the extension of the pipe, and lead wires 4a are raised and connected to the galvanic anode 4.

[Problem that the invention seeks to solve]

The conventional method had the following problems.

(1) In the method shown in Figure 2, electricity is supplied from a limited dark place on land, so the object to be protected from corrosion (in this example, submarine pipe 1)
If the area to be protected against corrosion is large, the ability of the galvanic anode 4 may be insufficient, and the anticorrosion effect may be significantly degraded.

(2) In the method shown in Fig. 3, there is no problem in terms of corrosion protection as a galvanic anode method for the submarine pipe 1, but the coating is divided due to the insertion of the galvanic anode 4, and this also causes the continuity of the reinforcement 6. As a result, strength problems may occur in structures where reinforcement is a strength factor.

(3) The method shown in Fig. 4 can be a solution to the problem in the case of Fig. 2, but since the terminal 3 is installed underwater, a coating of concrete or mortar, etc.
In addition to having to peel off the material, it is difficult to install. Furthermore, repair becomes impossible.

As a solution to this problem, it may be possible to have the terminal 3 protrude outside the coating 2 of the submarine pipe 1 while it is on land, but this may become an obstacle when moving on the rollers when it is pulled into the seabed, and the terminal 3 It is difficult to implement because it will cause damage.

[Means for solving problems]

The present invention has been made to solve these problems, and includes terminals each having a plurality of insulated lead wires each having a terminal at the tip attached at regular intervals to a structure before installation. The lead wires are guided through the reinforcement of the coating material to the surface of the coating material, and the terminals at the tip of the lead wires are coated with a thin coat of coating material. After the structure is installed, the terminals of each terminal are connected underwater. The present invention provides a method for installing a galvanic anode for cathodic protection by scraping the coating to expose one of the galvanic anodes and connecting it to the galvanic anode.

[Effect]

When pulling out a structure on a laying rack or roller, the terminal of the lead wire from the terminal is protected by a coating material and there is nothing protruding, so the structure can be moved safely without damage. I can do it.

Furthermore, after installation, by slightly scraping the coating material, the terminals can be exposed and the galvanic anode can be easily attached.

Furthermore, since the positive electrodes at this time are attached evenly over the entire area of the structure to be protected against corrosion, the anticorrosion effect can be extremely enhanced.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which (A) is a side view and (B) is a cross-sectional view. In the figure, a terminal 3 is welded to the outer peripheral surface of a submarine pipe 1.
From there, a plurality of insulated lead wires 3a are wired in the outer circumferential direction passing between the reinforcing bars 6. Each lead wire 3a has a terminal 7 near the surface of the coating material 2, and the lead wire 4a from the galvanic anode 4 is connected to one of the plurality of terminals 7 arranged in the circumferential direction while being buried in the coating material 2. is connected.

Next, this effect will be explained.

Before laying, terminals 3 are welded to the submarine pipe 1 at regular intervals on land, a plurality of terminals 7 guided from the terminals 3 by leads 1i13a are arranged in the circumferential direction of the submarine pipe 1, and the coating material 2 is installed near the surface of the After this, the coating will be applied to the entire surface and it will be pulled into the seabed and laid down. In this way, the terminal 7 will be coated with the coating material 2.
, so it will not be damaged in any way.
They are arranged at regular intervals in the length direction of the submarine pipe 1.

After that, among the plurality of terminals 7 arranged in the circumferential direction, a terminal 7 suitable for attaching the galvanic anode 4 is selected, the coating 2 on the surface of this terminal is scraped off, and the terminal 7 is guided from the galvanic anode 4 to the exposed terminal 7. Connect the lead wire 4a. By doing as shown in (B), galvanic anodes 4' can be installed on the submarine pipe 1 laid in the sea at regular intervals and on the average over the corrosion-protected area.

〔Effect of the invention〕

According to the present invention, since the terminal led from the terminal is arranged in advance near the coating surface, it is possible to install the cable without any obstruction to the structure, and it is also possible to easily attach the main anode downstream of the cable. Not only is this possible, but it can also be arranged evenly over the entire anti-corrosion surface, resulting in the effect of increasing anti-corrosion efficiency.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention, (A) is a side view, (B) is a cross-sectional view, and FIGS. 2 to 4 are schematic diagrams of a conventional example. 1: NPIf, W, 2 = coating material, 3: terminal, 4: i*electrode anode, 6: reinforcement, 7: terminal. Agent Patent Attorney Tadashi Sato Figure 3

Claims (1)

[Claims] Terminals each having a terminal at the tip and a plurality of insulated lead wires are attached to the structure before installation at regular intervals, and the lead wires are guided through between the reinforcements of the coating material to the surface of the coating material. After protecting the terminal at the tip of the lead wire with a thin coating material and then installing the structure, one of the multiple terminals of each terminal was
1. A method for attaching a galvanic anode for cathodic protection, comprising: scraping off a coating material to expose the galvanic anode and connecting it to the galvanic anode.