JPS59115770A - Coating method of inside surface of pipe - Google Patents

Abstract

PURPOSE:To coat satisfactorily a flowing material on the inside of a pipe by disposing elastic material packings on both sides of a bag formed of a porous film filled therein with the flowing material, inserting the same into a pipe, and pulling one of the packings to move the bag and to compress the bag thereby oozing the flowing material from the bag. CONSTITUTION:The 1st and 2nd packings 31, 32 are disposed before and behind a poreous bag 6, such as a fabric, filled therein with an adhesive agent 2, and are inserted into a pipe 1. A rope 41 is connected to the rear packing 31 and is passed in the front packing 32 so that it is connected to a traction rope 42. When the bag 6 is moved in this state in the pipe 1 by pulling the rope 42, the 1st and 2nd packings approach each other and compress the bag 6, then the agent 2 oozes from the very small holes of the bag and is coated on the inside surface of the pipe 1. The diameter of the 2nd packing 32 is made larger than the 1st packing 31.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of applying a liquid adhesive or paint to the inner surface of a tube.

[Background of the invention]

For example, when water pipes or gas pipes are old, construction methods are used such as lining the inner surface with epoxy paint or applying adhesive and then attaching the tube. It is also common practice to apply a viscous liquid to the inner surface of a tube for purposes other than those mentioned above. If these pipes are short, various coating methods can be considered, but in the case of long pipes, such as 100 m, special methods are required because the operation of climbing onto the coating jig must be performed 50 m from the pipe entrance. A method is needed.

Generally, in order to apply these viscous substances to the inner surface of a long pipe,
A method is used in which a hose with a spraying jig attached to its tip is inserted into a pipe, is run, and the viscous material is delivered by a pump, and the viscous material is sequentially sprayed onto the pipe wall. Another method is to form a coating of a certain thickness by pouring paint or the like into one end of a tube and pressing it with a backing made of an elastic material or the like.

In the former method, uniform coating can be achieved by adjusting the discharge pressure of the pump, the running speed of the injection jig, the viscosity of the viscous material, etc.; however, in order to coat the inside of a 100 m long pipe, A hose of 100 m or more is required, and in order to inject at the tip of this hose, there is a pressure loss due to the length of the hose, so the pressure for feeding the viscous material must be increased accordingly. Therefore, it is necessary to use a high-pressure hose, which has the drawback of requiring a considerably high equipment cost including the pump.

On the other hand, when applying paint by pressing it with a backing,
If a single pig is used, the viscous material in front of the backing will flow due to its own weight, resulting in incomplete application to the inner surface of the upper part of the pipe.

For this reason, for example, a method is used in which paint is placed between two backings and the paint is compressed by the backing so that it can be applied to the entire inner surface of the tube.

By the way, pipes such as water and gas pipes generally have branch points, and if the method described in ``U'' is used, viscous substances such as paint will flow into the branch pipe through the openings in the branch point, causing the branch point to become clogged. There's a problem.

The above conventional method will be explained with reference to the drawings.

As shown in Fig. 1, when a fluid material (2) such as adhesive or anticorrosive paint (adhesive is used as a typical example) is filled into the tube (1) (2) and pushed with a backing (3), Due to its fluidity, the adhesive (2) tends to flow forward, resulting in insufficient application to the upper inner surface of the tube (1), especially when the amount of adhesive decreases as the backing (3) moves forward. . In order to prevent this, it is possible to place a backing in front of the adhesive (2), but if the front and rear backings are simply connected at a certain interval, it may be necessary to press with a single backing when the adhesive decreases. The same phenomenon can be seen. Therefore, as shown in Figure 2, the second backing (3
2) is free from the rear first backing (31) and the rope (4) connected to it, so that the rear first backing (31) presses the adhesive (2). On the other hand, the second backing (32) at the front prevents the adhesive (2) from flowing, thereby creating pressure within the +4 adhesive and allowing it to be applied to the entire inner surface of the tube. However, because a certain pressure is generated in the adhesive, the adhesive (2) sprays out into the branch pipe at the branch part (5) that exists in the middle of the pipe, resulting in the problem that the branch part (5) is blocked. be.

[Summary of the invention]

The present invention was developed to solve this problem.When pressure is applied from the outside to a bag made of a material with fine holes, such as cloth, filled with a viscous substance, the viscous substance inside oozes out. This method uses backings at the front and rear of the bag, and connects both backings with a rope or rod-like object and pulls it into the pipe, bringing the front and rear backings relatively close to each other to open the bag. This method uses pressure to exude a viscous material and apply it to the inner surface of the tube.

[Detailed description of the invention]

An example of the present invention, as shown in FIG. When the rear first backing (31) is pulled forward by the tow rope (42), the rope (41) passes through the front second backing (32) and connects with the tow rope (42), forming an integrated rope. Natsu ℃ so the second backing (32
) and the knocking (31) come relatively close to each other, compressing the bag (6), which causes the adhesive (2) to ooze out from the micropores of the bag (6) and coat it on the inner surface of the tube. . Further, the portion of the rope (41) that passes through the second backing (32) may be a rod-shaped object. By adjusting the pulling speed of the jig to utilize the seepage of the adhesive, it is possible to apply a constant amount, and there is no sudden ejection even at the branching part, so there is no risk of blocking the branching part. It is something.

The backing is generally disk-shaped or spherical, but is not limited to this.

The material may be flexible and elastic, such as soft rubber or foamed plastic, and the size may be one that fits the inner diameter of the pipe. In addition, the force that presses the bag and causes adhesive, etc. to ooze out is easily transferred to the second backing (32) due to the frictional force acting between the backing (32) and the inner wall of the tube (1).
) does not move forward, so the diameter of the second backing (32) is larger than that of the first backing (32).
1) Larger values are generally desirable. However, this also results in too much pressure depending on the size of the micropores present in the bag, so it is necessary to adjust the size of the second backing (32) appropriately.

Good results were obtained when the bag was made of cloth made of cotton, nylon, tetron, etc., or a plastic sheet made of polyethylene, soft PVC, nylon, etc. with micropores formed therein.

As the coating progresses, the distance between the first backing (31) and the second backing (32) becomes narrower and the bag is compressed, so a flexible one is preferable.

Any number of bags may be used, but it is said that it is better to have multiple bags than one, because when the spacing between backings becomes narrower, the bags will shrink more smoothly, and will fit better into the pipe wall where they are sandwiched between backings. There are advantages.

In the case of one bag, a rope or rod-like object is inserted through the inside of the bag, or a long bag is arranged so as to be wound around the rope or rod-like object.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional method for coating the inside of a tube, and FIG. 2 is a longitudinal sectional view showing a method for coating the inside of a tube that is an improved method of the method shown in FIG. FIG. 3 is a longitudinal sectional view showing a method for coating the inner surface of a tube according to an embodiment of the present invention. (]) Pipe, (2) - adhesive, (31) first backing, (32)... second backing, (41) - rope,
(42) Tow rope, (5) branch pipe, (6) bag.

Claims (4)

[Claims] (1) In a bag made of a porous membrane that can permeate a fluid material,
Filled with a flowable material, the bag is placed between the first and second backings made of an elastic body connected by a loaf or rod M (object), and the loaf or rod is connected to the rod-shaped object. By pulling the bag into the tube with a traction lobe,
A method for coating an inner surface of a tube, comprising applying a fluid material exuding from the bag onto the inner surface of the tube. (2) The method for coating an inner surface of a tube according to claim (1), wherein the porous membrane is a cloth or a mesh-like material. (3) The distance between the first and second backings is 10 mm.
- the first and second
A method for coating an inner surface of a tube according to claim 1 or 2, wherein the bag placed between the backings is compressed. (4) A patent claim in which the rope connecting the first and second backings and the towing rope are an integrated rope, and the integrated rope is inserted through the center of the second backing on the towing rope side. The method for coating the inner surface of a pipe according to item (3).