JPH0783382A - Pipe end anticorrosion structure - Google Patents

Abstract

PURPOSE:To prevent generating red water and decreasing a life of a piping equipment by providing a pipe end anticorrosion structure of mounting a core of high pipe end corrosionproofing performance. CONSTITUTION:A seal agent is applied to an internal thread screwing part 16 and an annular protrusive part 17 in a body main unit 15 of a valve and a pipe fitting, and on the other hand, after the seal agent is applied to also an annular notched part 11 in a point end face 8 of a core 1 of mounting an O ring 10 to a peripheral part 3, the core 1 is screwed to the body main unit 15, next to screw a lining steel pipe 20 to the body main unit 15. After the seal agent is dried, seal parts 23a to 23d are formed, and since the O ring 10 comes into press contact with an internal peripheral surface 21 of the lining steel pipe 20 to form a good seal, red water is prevented from being generated by rusting a pipe end face 211 of the lining steel pipe 20, to enable a piping equipment to hold a good condition over a long period.

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 relates to a pipe for water supply equipment which prevents red water due to corrosion of the pipe end of a lining steel pipe.

[0002]

2. Description of the Related Art Generally, when piping a water supply facility, a lining steel pipe whose inner surface is coated with polyethylene, vinyl chloride or the like is used as a pipe material, and a valve, a pipe joint or the like is corrosion resistant to tap water. Some bronze is used. However, if piping is performed as it is, the pipe end of the lining steel pipe may come into contact with tap water at the connection part such as a valve or pipe joint, or electrolytic corrosion due to contact between metals with different potential differences such as iron and bronze. Red rust is generated, and this red rust elutes in tap water, causing deterioration of water quality and shortening the life of piping equipment. Therefore, as a measure against such red water, a plastic core is attached to the connection between the lining steel pipe and the valve or pipe fitting to block exposed rusty iron from contact with tap water. There is.

The structure of the above-mentioned conventional example is shown in FIG. According to this, in the core 33, an annular lip portion 37 that can be laterally deformed in the insertion direction of the inner surface coated steel pipe 40 is formed in the tubular body portion 35, and further, the outer peripheral portion is formed at the end portion of the body portion 35. Is formed with a collar portion 34 having an external thread 36, which is watertightly screwed into an internal thread 32 of a pipe connecting component 30 such as a valve or a pipe joint, and thereafter, an inner surface of the internal thread 32 of the pipe connecting component 30 is The outer thread 42 of the coated steel pipe 40 is screwed and connected. Thus, when the lip portion 37 of the core 33 is laterally deformed due to the insertion of the inner surface coated steel pipe 40, the lip portion 37 presses the coating layer 41 of the inner surface coated steel pipe 40 to form a seal, and the inner surface coated steel pipe The pipe end surface 43 of 40 is blocked so as not to come into contact with tap water. In addition, the coating layer 31 is also provided inside the pipe connection component 30 so that tap water does not leak from the outer screw 36 of the collar portion 34 of the core 33 to the pipe end face 43 side of the inner surface coated steel pipe 40.

[0004]

However, as in the conventional pipe end anticorrosion structure as described above, the pipe connecting part 3 is provided.
In the threaded portion where the inner screw 36 of 0 and the outer screw 36 of the collar portion 34 of the core 33 are screwed, the coating layer 31 is extended to the portion of the inner screw 36, or these inner screw and outer screw are bonded with an adhesive or the like. Even if it does, it is difficult to form a seal with a high degree of sealing because the portion having such a shape has a small sealing area, and the pipe end surface 43 of the inner surface-coated steel pipe 40 is prevented by tap water infiltrating from this portion. It has the problem of corroding and producing red water. In addition, the lip portion 37 of the core 33
Even if it is configured to press-contact the coating layer 41 of the inner surface coated steel pipe 40, it is difficult to obtain a seal with a high degree of sealing at this portion, and the pipe end surface of the inner surface coated steel pipe 40 due to tap water that has infiltrated from this portion. There is a problem of corroding 43 and generating red water. The plumbing equipment for water facilities
Once laid, it cannot be easily repaired or replaced, and therefore such a pipe end anticorrosion structure is also required to have high performance, and further development of a complete anticorrosion has been desired.

The present invention was developed in order to solve such a conventional problem, and compared with the conventional one,
The purpose of the present invention is to provide a pipe end anticorrosion structure equipped with a core having a higher pipe end anticorrosion property, prevent the generation of red water, and improve the life of piping equipment.

[0006]

In order to achieve the above object, a female screw threaded portion is formed at a connection portion of a body of a valve, a pipe joint or the like, and an annular projection is formed in the inner portion of the female screw threaded portion. And a flange portion having an external threaded portion that is screwed to the female threaded portion of the body body is formed on one end of the cylindrical core, and the outer peripheral part of the cylindrical core is formed. An O-ring is attached to the ring locking groove formed on the inner part of the lining steel pipe, and a male screw threaded portion that is screwed into the female screw threaded portion of the body is formed at the pipe end of the lining steel pipe. The surface is hermetically sealed via the O-ring, the flange portion of the core is inserted into the internally threaded portion of the body body, and the end surface of the flange portion of the core is inserted into the annular protrusion of the body body with a sealant. A contact seal is provided.
In this case, an annular notch is formed on the outer peripheral edge of the front end surface formed on the core, the annular notch is filled with a sealant, and the female screw engaging portion of the connecting portion of the body body and the flange of the core are formed. Fill the sealant between the male screw part of the part,
It is preferable to fill a sealant between the female screw threaded portion of the connecting portion of the body body and the male screw threaded portion of the lining steel pipe.

[0007]

According to the present invention thus constructed, the O-ring provided on the tubular core uniformly presses the inner peripheral surface of the lining steel pipe to obtain a complete hermetic seal. It is possible to prevent the infiltration of tap water. On the other hand, an annular protrusion is formed on the body body, and a sufficient sealing area is secured between this annular protrusion and the tip surface of the flange formed on the core. A transparent seal portion is formed, and it is possible to prevent tap water from infiltrating from the tip surface 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 sealing agent is filled therein, a ring-shaped seal having an appropriate thickness is formed in this part, and waterproofing is more complete. Can be

Further, if a sealing material is formed between the female screwed portion of the body body and the male screwed portion of the core to form the seal portion, the waterproofing from the tip side of the core is more complete. Can be one. Furthermore, if a sealant is formed between the female threaded portion of the body body and the male threaded portion of the lining steel pipe to form a seal portion, it is possible to prevent moisture and moisture from entering the body body from the outside. At the same time, the contact of dissimilar metals can be cut off, so that the outer surface of the pipe end portion and the pipe end surface of the lining steel pipe are not electrolytically corroded. In this way, the interaction between the hermetic seal formed by the O-ring mounted on the core and the seal portion formed by the sealant can completely prevent rusting of the pipe end surface of the lining steel pipe where rust is most likely to occur, so that rust can be prevented. Red water does not elute in tap water, and the piping equipment can be kept in good condition for a long period of time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the pipe end anticorrosion structure to which the present invention is applied will now be described in detail with reference to the drawings. In this embodiment, as shown in FIG. 1, a body 15 such as a valve and a pipe joint, a core 1 for pipe end anticorrosion, and a lining steel pipe 20 are provided. The body body 15 is cast from a metal having a corrosion resistance against tap water, for example, bronze,
A female screw screwing portion 16 is formed on the connecting portion 15a, and an annular protrusion 17 is further formed from the inner portion of the female screw screwing portion 16 to the flow path 18. The body 15 is capable of forming a so-called threaded joint, and can be applied to all kinds of piping materials including various valves such as gate valves and check valves, various pipe joints such as cheese and elbow, and piping equipment such as strainers. it can.

The core 1 has a flange portion 2 at one end of an outer peripheral portion 3.
To form the female screw engaging portion 16 of the body body 15 described above.
A male screw threaded portion 5 that is screwed to is formed, and an annular cutout portion 11 is formed on the outer peripheral edge of the tip surface 8 of the flange portion 2. Further, the outer peripheral portion 3 is formed with a ring engaging groove portion 7 formed by two annular protrusion portions 6 and 6, and an O-ring 10 is attached thereto. 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 integrally formed 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, and at the pipe end portion, a male screw threaded portion 22 that is screwed into the female screw threaded portion 16 of the body body 15 is formed. To be done.

Next, the operation of this embodiment will be described. First,
The sealing agent S is applied over the entire surface of the female threaded engagement portion 16 and the annular protrusion 17 of the body body 15, and at the same time, the sealing agent is applied to the annular notch portion 11 formed on the outer peripheral edge of the tip surface 8 of the core 1. After applying so as to fill S, the flange portion 2 of the core 1 is inserted into the female screw engaging portion 16 of the body body 15 so that the tip end surface 8 of the core 1 faces the annular protrusion 17 of the body body 15. Then, the male threaded portion 22 of the lining steel pipe 20 is inserted into the female threaded portion 16 of the body 15, and the pipe end face 24 is positioned at an appropriate position, for example, the flange 2 of the core 1.
The sealing agent S is dried until the sealing agent 23 d is formed, and the sealing portions 23 a, 23 b, 23 c, and 23 d are formed so that the sealing agent S is ready for use. Although not shown, it is preferable to apply the sealing agent S to the pipe end surface 24 of the lining steel pipe 20 as well. The sealant S used in this example is
Is a material that does not shrink in volume during drying, has appropriate elasticity after drying, and does not elute the components of the sealant S into tap water.

The O-ring 10 provided on the outer peripheral portion 3 of the core 1 uniformly press-contacts the inner peripheral surface 21 of the lining steel pipe 20 to obtain a complete hermetic seal, and complete infiltration of tap water from this portion of the core. Can be prevented. In this embodiment, the core 1
Since the rib 9 is formed in the fluid passage 4 to reinforce the outer peripheral portion 3, when the lining steel pipe 20 is screwed into the body body 15, the outer peripheral portion 3 of the core 1 is distorted in the inner diameter direction, O
The sealability between the ring 10 and the inner peripheral surface 21 of the lining steel pipe 20 is not deteriorated.

In this way, the core 1 is attached to the body body 15
When the lining steel pipe 20 is screwed into the female screw threaded portion 16 of the body body 15, the lining steel pipe 20 is screwed into the female threaded threaded portion 16, and between the annular projection 17 of the body body 15 and the tip surface 8 of the core 1, Female threaded portion 16 of main body 15 and flange portion 2 of core 1
The thin seal portions 23a, 23c, 23d are formed between the male screw threaded portion 5 and the female threaded portion 16 of the body 15 and the male threaded portion 22 of the lining steel pipe 20. Further, since the annular notch portion 11 is formed on the outer peripheral edge of the tip surface 8 of the core 1 and applied so as to fill the sealing agent S, the ring-shaped sealing portion 23 having an appropriate thickness is applied to this portion.
b is formed. In addition, these seal portions 23a to 2
3d is integrally formed.

In this embodiment, the body main body 15 is formed with an annular projection 17, and the annular projection 17 and the tip surface 8 of the core 1 are formed.
Since a sufficient sealing area is secured between the two and the sealing agent S is interposed, a complete sealing portion 23a can be obtained, and tap water can be prevented from infiltrating from the tip surface 8 side of the core 1. At this time, waterproofing can be made more complete by the seal 23b made of the sealing agent S filled in the annular cutout portion 11 of the tip surface 8 of the core 1. Further, when the sealing agent S is filled between the female screw engaging portion 16 of the body 15 and the male screw engaging portion 5 of the core 1 to form the seal portion 23c, the waterproof from the tip surface 8 side of the core 1 is obtained. Can be more complete. Further, when the sealing agent S is filled between the female screw threaded portion 16 of the body body 15 and the male threaded portion 22 of the lining steel pipe 20 to form the seal portion 23d, moisture and moisture from the outside of the body body 15 are formed. Since it is possible to prevent the infiltration of foreign matter and to prevent the dissimilar metal contact between the body body 15 made of bronze and the lining steel pipe 20 made of iron to perform good insulation, the outer surface of the pipe end portion of the lining steel pipe 20 and the pipe end surface 24 is not electrolytically corroded.

As described above, in this embodiment, the lining steel pipe 20 that is most likely to be rusted due to the interaction between the hermetic seal formed by the O-ring 10 mounted on the core 1 and the seal portions 23a to 23d formed of the sealant S. Since the rustproofing of the pipe end surface 24 can be completely performed, rust does not elute into tap water to generate red water, and the pipe 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, the annular projection is formed in the inner portion of the connecting portion of the body such as the valve or the pipe joint to distribute the sealant. Then
In addition, a sealant is arranged on the female screwed portion of the connection portion of the body body to seal the threaded portion of the core and the threaded portion of the lining steel pipe, and the O-ring provided on the outer periphery of the core further secures the lining steel pipe Since the inner peripheral surface is completely hermetically sealed, the pipe end face of the lining steel pipe is never corroded, and it is possible to provide a pipe end anticorrosion structure with higher performance than the conventional one. Can be effectively achieved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 core 2 flange part 3 outer peripheral part 5 male screw screwing 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 engaging part 17 annular protrusion 20 lining steel pipe 21 Inner peripheral surface 22 Male screw threaded portion S Sealant

Claims (4)

[Claims] 1. A female screw threaded portion is formed at a connecting portion of a body such as a valve or a pipe joint, and an annular protrusion is formed in a deep portion of the female screw threaded portion. A flange portion is formed at one end having a male screw threaded portion that is screwed to the female threaded portion of the body body on the outer peripheral portion, and an O-ring is provided in the ring locking groove portion formed on the outer peripheral portion in the middle of this tubular core. Wear it, and
A male screw threaded portion that is screwed into a female threaded portion of the body is formed at the pipe end of the lining steel pipe, and the inner peripheral surface of the lining steel pipe is hermetically sealed via the O-ring and the female body body is A pipe end anticorrosion structure characterized in that a flange portion of a core is inserted into a screw threaded portion, and an end surface of a flange portion of the core is brought into contact with and sealed to an annular projection of a body body through a sealant. 2. The pipe end anticorrosion structure according to claim 1, wherein an annular notch is formed on the outer peripheral edge of the tip surface formed on the core, and the annular notch is filled with a sealant. 3. The pipe end anticorrosion structure according to claim 1, wherein a sealant is filled between the female screw engagement portion of the connection portion of the body body and the male screw engagement portion of the flange portion of the core. 4. The pipe end anticorrosion structure according to claim 1, wherein a sealant is filled between the female screw threaded portion of the connection portion of the body body and the male screw threaded portion of the lining steel pipe.