JPH0459516B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to pipe connection parts using pipe joints in piping systems buried underground such as gas pipes and water pipes, that is, pipe joints and the like. The present invention relates to a method for constructing a corrosion-proof cover for a pipe joint, which is constructed at a piping site so as to watertightly surround and cover a connected pipe portion with the corrosion-proof cover.

[Prior Art] Generally, as a corrosion prevention measure for underground piping systems such as gas pipes, synthetic resin pipes such as PVC pipes and anti-corrosion treated pipes whose outer surfaces are lined with a synthetic resin layer are used. Measures are taken to surround the pipe connection portion by a pipe joint with an anti-corrosion cover.
Conventional anti-corrosion covers used for such anti-corrosion construction include, for example, a cover body made of synthetic resin that is divided into two parts at the center, and the peripheral edge of one divided cover body part and the peripheral edge of the other divided cover body part. and the parts are butt-adhered to each other with an adhesive, except for the part where the connected pipe part connected to the pipe joint penetrates, and the peripheral edge parts of both split cover main body parts at the part where the connected pipe part penetrates. of,
By adhering the peripheral portion to the pipe to be connected with an adhesive and wrapping the outer surfaces of the peripheral portion and the pipe to be connected, the peripheral portion is sealed and fixed to the pipe to be connected. A predetermined anti-corrosion treatment has been carried out by enclosing the pipe joint and the connected pipe portion from both sides in a watertight manner using the split cover main body portion.

In addition to this, there is also a case where the internal space of the shell covering the pipe connection part is filled with liquid rubber, etc., and this shell is used to surround and cover the pipe connection part (Japanese Patent Laid-Open No. 57-76396
(Refer to Publication No. 2003) or the pipe connection part by applying a self-adhesive layer consisting mainly of butyl rubber and containing polyisobutylene low polymer to the entire inner surface of the corrosion-proof cover to a thickness of 0.2 to 0.5 mm. A case is known in which a cover surrounds a pipe connection portion (see Japanese Patent Application Laid-open No. 54892/1983).

[Problems to be Solved by the Invention] The above conventional case had the following problems. In other words, the soil in which gas pipes are buried often contains many sharp objects such as needles, nails, and debris, and during the soil covering work after piping, the sharp objects contained in the soil are often removed. It may stick to the anti-corrosion cover body and cause holes. In particular, in the case of conventional anti-corrosion covers, if a sharp object pierces the area other than the peripheral edge of the main body of the split cover, that is, the area where no adhesive or adhesive tape is applied, and the hole ruptures. There is a problem in that water in the soil and the like enters the cover body through the holes, impairing the corrosion protection effect on the pipe joint. Furthermore, such holes caused by sharp objects in the cover body are usually not noticed during soil covering work, and the above problem is extremely serious in preventing corrosion prevention measures in piping systems such as gas pipes.

This invention was made in view of the above circumstances.
Even if a hole is created in the cover body by a sharp object such as a needle during soil covering work, the hole can be automatically and reliably sealed to maintain sufficient anti-corrosion effect on the pipe connection part by the pipe fitting. Moreover, it is an object of the present invention to provide a construction method for an anticorrosion cover for a pipe joint that has excellent workability.

[Means for Solving the Problems] In order to achieve the above object, a method for constructing an anti-corrosion cover for a pipe joint according to the present invention is to apply a highly adhesive and highly viscous fluid to the inner surface of the cover body over the entire surface. Form an adhesive layer such as unvulcanized butyl rubber with a thickness of at least 1.5 mm,
When surrounding the pipe connecting portion with the cover body, the adhesive layer having adhesiveness and fluidity is pressed against the outer surface of the pipe connecting portion. be.

[Function] According to the above configuration, if a sharp object such as a needle pierces the cover body during soil covering work after piping and a hole is punctured, the entire inner surface of the cover body remains fluid and sticky. Since the formed adhesive layer portion flows into the hole and seals the hole, water and the like can be reliably prevented from entering the cover body after piping is installed. In addition, when the cover body is placed around the pipe connection part, the adhesive layer is pressed against the outer surface of the pipe connection part, and the adhesive layer flows to match the outer surface condition of the pipe connection part. Regardless of the enclosing position of the
Sealing by the cover body is ensured.

[Example] Hereinafter, a method for constructing an anticorrosion cover according to the present invention will be specifically described based on an example shown in FIGS. 1 to 5. In this example, a pipe fitting A and a T
This figure shows an example in which the present invention is applied to an anti-corrosion cover for covering connected pipe portions B, which are connected in a letter shape.

That is, the anticorrosion cover 1 of this embodiment includes a cover body 2 made of synthetic resin that can surround the pipe joint A and each connected pipe portion B connected thereto in a bag shape.
and a binding band 3 made of synthetic resin for securing the cover body 2 to the connected pipe portion B.
It consists of...

As shown in FIGS. 1 and 2, the cover main body 2 is configured so that it can be folded in two along a bending line 2a at the center. 4 has a symmetrical shape around the bending line 2a. At the center of the inner surface of each split cover main body portion 4, there is a pipe fitting surrounding recess 4 into which one side portion of the pipe fitting A can be inserted.
In addition, tube surrounding recesses 4c are formed in the peripheral edge 4a, into which one side portion of B of each connected portion can be inserted, and in the peripheral edge 4a, portions near both sides of each tube surrounding recess 4c are formed. A pair of bondage band insertion holes 4d, 4d are formed in each of the holes. In addition, a pair of positioning holes that can be engaged with each other are provided at appropriate positions on the inner surfaces of the peripheral edges 4a, 4a of the two split cover main body portions 4, 4, and at corresponding portions across the bending line 2a. Concave portions 4e, 4e and convex portions 4f, 4f are formed, respectively. Incidentally, in this embodiment, the cover main body 2 is constructed by bending a relatively thin plate-shaped piece of low-density polyethylene at the center as described above, and subjecting it to uneven processing.

Then, as shown in FIG. 2, this cover body 2
In other words, the inner surfaces of the two divided cover main body parts 4, 4 are coated with an adhesive layer 5 having high adhesiveness, high viscosity, and fluidity over the entire surface thereof. This adhesive layer 5 is formed by applying unvulcanized butyl rubber to a pressure of about 1.5 mm over the entire inner surface of the cover body 2. In addition, as shown in FIG. 3, the adhesive layer 5
A vinyl chloride release film 6 of approximately 0.5 mm is attached to the entire surface of the container to prevent the adhesive layer 5 from adhering during transportation.

In addition, as shown in FIGS. 1 and 5, each bondage band 3 has a saw-blade-shaped engagement convex portion 7a formed on the surface of one end portion 3a, and the one end portion 3a is formed on the other end.
It is formed by integrally forming an annular locking part 3b for inserting and locking the cover body 2, and is inserted into each binding band insertion hole 4d of the cover body 2. Inside the locking portion 3b, a locking tongue 7c is provided which faces the insertion path of the one end portion 3a and forms a saw-toothed engagement recess 7b, as shown in FIG. The engagement between the mating protrusion 7a and the engaging recess 7b allows the one end portion 3a of the binding band 3 to be freely pulled out from the locking portion 3b, but prevents it from being pulled out, that is, reducing the amount of pulling out. It's getting old. In other words, each bondage band 3 is
By simply inserting the one end portion 3a through the locking portion 3b and pulling it out from the locking portion 3b, the cover body 2 can be tied tightly and the tied state can be maintained irreleasably.

Next, the anti-corrosion cover 1 configured as described above will be explained.
The construction procedure for covering the pipe fitting A and each connected pipe portion B connected thereto in a watertight manner will be explained.

That is, after peeling off the release film 6 from the adhesive layer 5, the cover body 2 is bent along the bending line 2, and the peripheral edge 4 of the two divided cover body parts 4, 4 is separated.
a, 4a, and both pipe joint surrounding recesses 4b, 4.
The pipe joint A and each connected pipe portion B are positioned in the space formed by the pipe fitting A and the space formed by the pipe enclosing recesses 4c and 4c, respectively. At this time, the adhesive layer 5 applied to the inner surface of the cover body 2
flows to match the external surface condition of the connected pipe portion B, and as a result, both the divided cover body portions 4, 4
The adhesive layer 5 is inserted without a gap between the peripheral edges 4a, 4a and the outer surface of the corresponding connected pipe portion B, so that the peripheral edges 4a, 4a are bonded against each other, and each tube surrounding The concave portions 4c, 4c are bonded to the outer surface of each connected tube portion B in such a manner as to hold it. In addition, proper abutment between the two split cover main body parts 4, 4 is made using the respective concave portions 4e and convex portions 4.
This can be done reliably and easily by engaging f.

After that, one end portion 3a of each bondage band 3 is inserted through the locking portion 3b and pulled out by a predetermined amount.
By tensioning each bondage band 3 in an annular manner, the cover body 2 surrounds each tube end side portion a.
Each part is tightly secured to each tube end side portion a (see Fig. 4). Note that the surplus portion of the one end side portion 3a of each binding band 3 may be cut off after binding.

In this way, both the split cover body parts 4, 4
When the pipe joint A and each connected pipe portion B connected thereto are surrounded and covered from both sides, pipe surrounding recesses 4c are formed among the peripheral edges 4a, 4a of both cover main body portions 4, 4. The parts other than the parts where the adhesive layers 5, 5 are bonded together are strongly butt-adhered, and the parts where the pipe surrounding recesses 4c are formed after the peripheral parts 4a, 4a are formed by the adhesive layers 5. Since it is strongly sealed and fixed to the outer surface of the connected pipe portion B by adhesion and binding by the binding band 3, the pipe connecting portion by the pipe joint A can be reliably and well waterproofed or corrosion-proofed. Moreover, if the cover body 2 is punctured by a sharp point such as a needle in the soil during soil covering work after construction of the piping and anti-corrosion cover 1, the adhesive made of unvulcanized butyl rubber that has adhesiveness and fluidity The layer 5 quickly flows and enters the hole and seals it, thereby preventing water in the soil from entering the cover body 2 and impairing the waterproofing or anticorrosion effect.

Note that the structure of the anticorrosion cover is not limited to the above embodiment, and the design can be changed as appropriate depending on the shape of the pipe joint to be covered. For example, the cover body 2 may be foldable into three or more divided cover body parts,
Alternatively, the cover may be separated into a plurality of main body parts.

Further, the binding band 3 does not have the structure as in the embodiment described above, but may be one in which a string or band-like member is simply tied in a ring shape and bound. However, if the structure is as in the embodiment described above, there is an advantage that the binding work can be performed extremely easily and quickly. The material of the binding member is not limited to synthetic resin, but may also be metal.

Furthermore, various synthetic resins other than low-density polyethylene can be selected as the constituent material of the cover body 2, but when molding is performed using a low-density polyethylene plate as in the above embodiment, molding is easy. It is economically advantageous in terms of production.

[Effect of the invention] As described above, according to this invention, at least
The pipe connection part is covered with a cover body, which is made of an adhesive layer made of adhesive and fluid unvulcanized butyl rubber or the like, formed to a thickness of about 1.5 mm, over the entire inner surface of the cover body. If a sharp object such as a needle or nail pierces the cover body during soil covering work after piping, and a hole is punctured, the hole can be reliably and quickly sealed by the flow of the adhesive layer. It is possible to prevent water and the like from entering and maintain the desired anticorrosion effect reliably and well.

In addition, when enclosing the cover body, by applying a fluid and sticky adhesive layer to the outer surface of the pipe connection part while enclosing the cover body, the anti-corrosion cover body is covered with a single synthetic resin plate. Even if the cover is constructed by bending, as the bending progresses, the adhesive layer will flow to match the outer surface of the pipe connection part, and the gap between the cover body and the pipe connection part will become smaller. Even if the coating is applied without changing uniformly around the entire circumference, the cover body can be adhered to the outer surface of the pipe connection portion without any gaps after coating. Therefore, the anticorrosive cover does not require any special technique or skill, and can be easily and efficiently applied, and the anticorrosion effect of the pipe joint can be significantly enhanced.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the method for constructing a corrosion-proof cover for a pipe joint according to the present invention.
The figure is a plan view showing the state in which the anti-corrosion cover is unfolded, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is an enlarged detailed view of the part in Fig. 2, and Fig. 4 is a pipe joint with the anti-corrosion cover. FIG. 5 is an external perspective view showing a state in which the pipe connecting portion is covered by the method, and FIG. A...Pipe fitting A (pipe connection part by pipe fitting), B
...Connected pipe part (pipe connection part by pipe fitting),
1... Corrosion protection cover, 2... Cover body, 2a...
Bending line, 3... Bondage band, 4... Divided cover body portion, 4a... Periphery, 4b... Pipe joint surrounding recess, 4c... Pipe surrounding recess, 5... Adhesive layer, 6...
...Peelable film.

Claims (1)

[Claims] 1. In a method of constructing an anti-corrosion cover for a pipe joint that surrounds and watertightly covers the pipe connection part of the pipe joint, an unvulcanized material with high adhesiveness and viscosity and fluidity is applied to the inner surface of the cover body over the entire surface. An adhesive layer such as butyl rubber is formed to a thickness of at least about 1.5 mm, and when the cover body is applied to surround the pipe connection part, the adhesive layer in a state with adhesiveness and fluidity is A method for constructing an anti-corrosion cover for a pipe joint, which is characterized by covering the outer surface of a pipe joint while being pressed against it.