JP3106381B2 - Pipe end corrosion protection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe end anticorrosion structure, and more particularly to an apparatus for preventing red water due to corrosion of a pipe end of a lining steel pipe in a pipe of a water supply facility.

[0002]

2. Description of the Related Art In general, when piping water equipment, a lining steel pipe whose inner surface is coated with polyethylene, vinyl chloride, or the like is used as a pipe material, and valves and pipe joints have corrosion resistance against tap water. A bronze thing is used. However, if piping is performed as it is, the pipe end of the lining steel pipe will be in contact with tap water at the connection parts such as valves and pipe joints, or electrolytic corrosion due to the contact of metals with different potential differences such as iron and bronze. Red rust is generated, and this red rust is eluted in tap water, causing deterioration of water quality and shortening the life of piping equipment. Therefore, as a countermeasure against such red water, a plastic core is attached to the connection between the lining steel pipe and the valve or pipe joint, etc., so that the exposed portion of the rusting iron is prevented from coming into contact with tap water. I have.

FIG. 2 shows the configuration of the above-mentioned conventional example. According to this, in the core 33, an annular lip portion 37 that can be deformed sideways in the insertion direction of the inner surface coated steel pipe 40 is formed on the cylindrical body portion 35, and further, an outer peripheral portion is formed on an end portion of the body portion 35. Is formed with a flange portion 34 having an external thread 36, which is screwed to an internal thread 32 of a pipe connection part 30 such as a valve or a pipe joint in a watertight manner. The external thread 42 of the coated steel pipe 40 is screwed and connected. Thereby, when the lip portion 37 of the core 33 is deformed sideways with the insertion of the inner coated steel tube 40, the lip portion 37 presses the coating layer 41 of the inner coated steel tube 40 to form a seal, and the inner coated steel tube is formed. The tube end surface 43 of the tube 40 is shut off so as not to come into contact with tap water. Further, the coating layer 31 is also provided inside the pipe connection component 30 so that tap water does not leak from the external thread 36 of the flange 34 of the core 33 to the pipe end face 43 side of the inner coated steel pipe 40.

[0004]

However, as in the above-described conventional pipe end anticorrosion structure, the pipe connecting part 3 has a disadvantage.
At the screwing portion between the inner screw 36 of the core 33 and the outer screw 36 of the flange portion 34 of the core 33, the coating layer 31 is extended to the portion of the inner screw 36, or the inner screw and the outer screw are bonded with an adhesive or the like. Even so, it is difficult to form a high-sealing seal because the area of such a shape has a small sealing area. There is a problem of causing corrosion and generating red water. The lip 37 of the core 33
However, it is difficult to obtain a high-sealing seal at this portion even if the coating layer 41 of the inner-coated steel pipe 40 is pressed against the inner surface of the inner-coated steel pipe 40. 43, and has a problem of generating red water. Plumbing equipment for water supply equipment
Once laid, it cannot be easily repaired or replaced. Therefore, such a pipe end anticorrosion structure also requires high performance, and further development of a completely anticorrosion structure has been desired.

[0005] The present invention has been developed to solve such a conventional problem.
An object of the present invention is to provide a pipe end anticorrosion structure equipped with a core having a higher pipe end anticorrosion property, to prevent the generation of red water and to improve the life of piping equipment.

[0006]

In order to achieve the above-mentioned object, the present invention forms a female screw thread at a connection portion of a body body such as a valve or a pipe joint, and forms a female screw thread at the back of the female screw thread. An annular projection is formed at the end of the tubular core , and at one end of the cylindrical core , a flange having an external threaded portion which is screwed to the female threaded portion of the body main body is formed at an outer peripheral portion, and a lining steel pipe tube is formed. A ring member formed at an end portion with a male screw threaded portion to be screwed into the female screw threaded portion of the body main body, and formed at an outer peripheral portion in the middle of the cylindrical core.
Attach an O-ring to the groove, and insert a line through this O-ring.
Seals the inner peripheral surface of the thinning steel pipe and the outer peripheral surface of the cylindrical core
And, by screwing a flange portion of the cylindrical core in the female screw thread portion of the main body, the front end surface of the flange portion of the cylindrical core and abutting the seal via the sealing agent annular projection of the main body, And,
An annular notch is formed in the outer peripheral edge of the tip end surface of the cylindrical core,
Fill the annular cutout with sealing agent
The projection and the flange of the cylindrical core were hermetically sealed . In this case, filled with a sealant between the male screw threaded portion of the flange portion of the female screw threaded portion and the core of the connecting portion of the ball Di body, further,
It is preferable to fill a sealant between the female screw portion of the connection portion of the body main body and the male screw thread portion of the lining steel pipe.

[0007]

According to the present invention constructed as described above, the O-ring provided on the cylindrical core uniformly presses the inner peripheral surface of the lining steel pipe to obtain a complete hermetic seal. Tap water can be prevented from seeping. On the other hand, an annular projection is formed on the body, and a sufficient sealing area is secured between the annular projection and the front end surface of the flange formed on the core. The sealing portion is formed to prevent infiltration of tap water from the tip end side of the core. At this time, an annular notch is formed on the outer peripheral edge of the tip end surface of the core, and when a sealant is filled therein, an appropriately thick ring-shaped seal portion is formed in this portion, and waterproofing is more complete. It can be.

Further, if a sealant is formed between the female screw portion of the main body and the male screw portion of the core to form a seal portion, waterproofing from the tip end side of the core is more complete. Things. Further, when a sealing agent is filled between the female screwed portion of the body main body and the male screwed-in portion of the lining steel pipe to form a seal portion, infiltration of moisture or moisture from the outside of the body main body can be prevented. At the same time, the contact of the dissimilar metal can be cut off, so that the outer surface of the pipe end and the pipe end face of the lining steel pipe do not undergo electrolytic corrosion. In this way, the interaction between the hermetic seal formed by the O-ring mounted on the core and the seal formed by the sealant can completely prevent rust on the pipe end surface of the lining steel pipe where rust is most likely to occur. Red water is not generated by elution in tap water, and the piping equipment can be kept in a good state for a long period of time.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an embodiment of a pipe end anticorrosion structure to which the present invention is applied. In this embodiment, as shown in FIG. 1, a body main body 15 such as a valve or a pipe joint, a tubular core for protecting the pipe end (hereinafter simply referred to as a core).
1 ) and a lining steel pipe 20. The body body 15 is made of a metal having corrosion resistance to tap water,
For example, it is cast by bronze, and a female screw portion 16 is formed on the connection portion 15a.
An annular protruding portion 17 is formed from the back to the flow path 18. The body main body 15 can form a so-called threaded joint, and can be applied to various piping materials including, for example, various valves such as gate valves and check valves, various pipe joints such as cheeses and elbows, and piping devices such as strainers. it can.

The core 1 has a flange 2 at one end of an outer periphery 3.
And the female screw threaded portion 16 of the body body 15 described above is formed.
Is formed on the outer peripheral edge of the distal end surface 8 of the flange portion 2. A ring engaging groove 7 is formed in the outer peripheral portion 3 by two annular ridges 6, 6, and an O-ring 10 is mounted therein. The core 1 is formed so as to penetrate the fluid flow path 4 in the coaxial direction, and is integrally formed of a corrosion-resistant material such as plastic. In this embodiment, a plurality of, for example, six ribs 9 are formed integrally with the core 1 in the fluid flow path 4 of the core 1 to increase the strength of the core 1. The lining steel pipe 20 is formed by coating the inner surface of the steel pipe with polyethylene powder or hard vinyl chloride. At the pipe end, a male screw threaded part 22 that is screwed into the female screw threaded part 16 of the body body 15 is formed. Is done.

Next, the operation of this embodiment will be described. First,
The sealant S is applied over the entire surface of the female screw portion 16 and the annular protrusion 17 of the body body 15, while the sealant S is also applied to the annular notch 11 formed on the outer peripheral edge of the distal end surface 8 of the core 1. After S is applied so as to be filled, the flange portion 2 of the core 1 is inserted into the female screw threaded portion 16 of the body body 15 so that the distal end surface 8 of the core 1 faces the annular projection 17 of the body body 15. Then, the male screw threaded portion 22 of the lining steel pipe 20 is inserted into the female screw threaded portion 16 of the body main body 15, and the pipe end face 24 is positioned at an appropriate position, for example, the flange 2 of the core 1.
Until the sealant S has dried, and after the sealant S has dried, the seal portions 23a, 23b, 23c, and 23d are formed to be ready for use. Although not shown, the sealing agent S is preferably applied to the pipe end face 24 of the lining steel pipe 20. The sealant S used in this embodiment
It is necessary to use a material which does not shrink in volume during drying, has an appropriate elasticity even after drying, and does not elute components of the sealant S into tap water.

The O-ring 10 provided on the outer peripheral portion 3 of the core 1 uniformly presses the inner peripheral surface 21 of the lining steel pipe 20 to obtain a complete hermetic seal, thereby completely preventing permeation of tap water from this portion of the core. Can be prevented. In this embodiment, the core 1
Since the outer peripheral portion 3 is reinforced by forming the rib 9 in the fluid flow path 4, the outer peripheral portion 3 of the core 1 is distorted in the inner diameter direction when the lining steel pipe 20 is screwed into the body main body 15, O
The sealing performance between the ring 10 and the inner peripheral surface 21 of the lining steel pipe 20 is not reduced.

In this manner, the core 1 is connected to the body 15
When the lining steel pipe 20 is screwed into the female screw threaded portion 16, the gap between the annular projection 17 of the body main body 15 and the distal end face 8 of the core 1 is increased. Female screw thread 16 of main body 15 and flange 2 of core 1
Thin seal portions 23a, 23c, and 23d are formed between the male screw portion 5 of the main body 15 and the male screw portion 22 of the lining steel pipe 20. Further, since an annular notch 11 is formed on the outer peripheral edge of the distal end surface 8 of the core 1 so as to fill with the sealing agent S, a ring-shaped sealing portion 23 having an appropriate thickness is provided in this portion.
b is formed , the annular projection of the body body and the flange of the core
The part is hermetically sealed. In addition, these seal parts 23a to 23d are formed integrally.

In the present embodiment, an annular projection 17 is formed on the body body 15, and the annular projection 17 and the distal end face 8 of the core 1 are formed.
Since the sealing agent S is interposed while ensuring a sufficient sealing area therebetween, a complete sealing portion 23a can be obtained, and infiltration of tap water from the distal end surface 8 side of the core 1 can be prevented. At this time, the waterproofness can be made more complete by the seal 23b made of the sealant S filled in the annular notch 11 of the distal end surface 8 of the core 1. When the sealant S is also filled between the female screw portion 16 of the body 15 and the male screw portion 5 of the core 1 to form the seal portion 23 c, waterproofing from the distal end surface 8 side of the core 1 is achieved. Can be more complete. Further, when the sealant S is formed by filling the sealant S between the female screw threaded portion 16 of the body main body 15 and the male screw threaded portion 22 of the lining steel pipe 20, moisture or moisture from the outside of the body main body 15 is formed. Of the lining steel pipe 20 and the end face of the lining steel pipe 20 and the pipe end face. 24 does not cause electrolytic corrosion.

As described above, in the present embodiment, the interaction between the hermetic seal by the O-ring 10 attached to the core 1 and the seal portions 23a to 23d formed by the sealant S causes the lining steel pipe 20 in which rust is most likely to occur. Since the rust preventive measures for the pipe end surface 24 can be completely performed, rust does not elute into tap water and red water is not generated, and the piping equipment can be kept in a good state for a long time.

[0016]

As is apparent from the above description, according to the pipe end anticorrosion structure of the present invention, an annular projection is formed in the inner part of the connection part of the body body such as a valve or a pipe joint, and the sealant is distributed. And
In addition, an annular notch is formed on the outer peripheral edge of the tip surface of the cylindrical core
Then, fill the annular notch with sealant
The annular projection and the cylindrical core flange are hermetically sealed.
Between the annular projection and the tip of the flange of the cylindrical core.
After securing a sufficient sealing area,
And an appropriately thick ring on the outer peripheral edge of the tip surface of the cylindrical core.
Is formed, so that the cylindrical core tip surface side
Such water can be reliably prevented from entering. In addition, a sealing agent is disposed on the female screw threaded portion of the connection portion of the body main body to seal the threaded portion of the tubular core and the threaded portion of the lining steel pipe, and further, the outer peripheral portion of the tubular core. The inner peripheral surface of the lining steel pipe is completely hermetically sealed by the O-ring provided in the pipe, so that the pipe end face of the lining steel pipe does not corrode at all, and provides a pipe end corrosion prevention structure with higher performance than before. And achieve the intended purpose effectively.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the structure of one embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core 2 Flange part 3 Peripheral part 5 Male screw thread part 7 Ring locking groove part 8 Tip surface 10 O-ring 11 Annular notch part 15 Body main body 15a Connection part 16 Female screw thread part 17 Annular protrusion 20 Lining steel pipe 21 Inner peripheral surface 22 Male screw thread S Sealant

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 58/18 F16K 25/04

Claims (3)

(57) [Claims] 1. A valve, to form a female screw threaded portion to the connecting portion of the main body such as a pipe joint, forming an annular projection on the inner part of the female screw thread portion, whereas, the cylinder Joko A At one end, a flange portion having an external threaded portion screwed to the female threaded portion of the body main body is formed on the outer peripheral portion, and is screwed into the female threaded portion of the body main body at the pipe end of the lining steel pipe. Ring member formed on the outer peripheral part in the middle of the cylindrical core
Attach an O-ring to the groove, and insert a line through this O-ring.
Seals the inner peripheral surface of the thinning steel pipe and the outer peripheral surface of the cylindrical core
And, by screwing a flange portion of the cylindrical core in the female screw thread portion of the main body, the front end surface of the flange portion of the cylindrical core and abutting the seal via the sealing agent annular projection of the main body, And,
An annular notch is formed in the outer peripheral edge of the tip end surface of the cylindrical core,
Fill the annular cutout with sealing agent
A pipe end anticorrosion structure in which a projection and a flange of a cylindrical core are hermetically sealed . 2. A female threaded portion of a connection portion of a body main body and a female screw portion.
2. The pipe end anticorrosion structure according to claim 1 , wherein a sealant is filled between the male screw threads of the flange portion . 3. A female screw threaded portion of the connecting portion of the main body and La
The pipe end anticorrosion structure according to claim 1 or 2 , wherein a sealant is filled between the inner thread and the male screw threaded portion.