JPH061970U - Pipe end anticorrosion structure - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent red water from being generated by corroding the pipe end of the inner surface resin lined steel pipe screwed to the pipe connection end of a valve, pipe joint, etc. due to the fluid in the pipe. [Structure] An annular groove provided on an outer peripheral surface 2c of a body portion 2b of a sleeve 2 having a collar-shaped male screw portion 2a which is screwed to a screw portion 1b at a pipe connection end portion 1a of a main body 1 A seal ring 4 having an oblong cross section is attached to 2d to seal the space between the inner surface resin-lined steel pipe 3 and the inner surface 2g of the sleeve 2 and a conical surface 2 slightly recessed toward the center.
A pipe end anticorrosion structure in which h is hermetically brought into contact with an annular flat step portion 1c provided at the innermost portion of the female screw portion 1b of the main body 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pipe end anticorrosion structure, and in particular, an inner resin lined steel pipe used for piping for water supply, hot water supply, etc. generates corrosive rust at the pipe end connected to a valve, pipe joint, etc., and produces red water. The present invention relates to a pipe end anticorrosion structure provided at a pipe connection end of a main body of a valve, a pipe joint or the like in order to prevent the above.

[0002]

[Prior art]

 In order to prevent rust from being generated in pipes for water supply, hot water supply, etc., and the rust being mixed with water to form so-called red water, an inner resin lined steel pipe such as a vinyl chloride lined steel pipe has been widely used. However, the problem was that the cut end of the steel pipe that was not lined with resin was exposed in the water at the pipe end connected to the valve, pipe joint, etc. and rusted, and red water was still generated. For this reason, the pipe connection end of the main body of the valve, pipe joint, etc., has a pipe end anticorrosion structure in which the steel pipe cut surface of the pipe is not exposed in water.

FIG. 6 is a partial vertical cross-sectional view showing a conventional example of a gate valve in which a pipe connection end of a main body has a pipe end anticorrosion structure. In FIG. 6, 21 is a main body of the gate valve, 22 is a sleeve, 23 is an inner resin lining steel pipe, and 24 and 25 are discs and stems of the valve. Reference numeral 21a denotes a pipe connection end of the main body 21, and the pipe connection end 21a is provided with a female threaded portion 21b. The female threaded portion 21b is provided with a male threaded portion 23a provided on the inner surface resin lined steel pipe 23. Is screwed in. Reference numeral 23b is a coating layer for the inner surface resin lined steel pipe 23.

A collar-shaped male threaded portion 22 a formed on the sleeve 22 is screwed into the female threaded portion 21 b of the main body 21, and the male threaded portion 22 a and the female threaded portion 21 b are screwed together to form the main body 21 and the sleeve 22. The outer peripheral surface 22c of the body portion 22b of the sleeve 22 is in pressure contact with the inner peripheral surface 23c of the coating layer 23b of the inner surface resin lining steel pipe 23, and the space between the inner surface resin lining 23 and the sleeve 22 is sealed. is doing. Therefore, the fluid inside the inner resin lined steel pipe 23 and the main body 21 of the gate valve does not come into contact with the metal exposed surface 23d at the pipe end of the inner resin lined steel pipe 23. Therefore, the pipe connection end 21a of the main body 21 is It has a pipe end anti-corrosion structure.

In this structure, the sleeve 22 is generally made of synthetic resin and has some elasticity, but the diameter dimension of the outer peripheral surface 22 c of the sleeve 22 and the inner peripheral surface 23 c of the inner surface resin-lined steel pipe 23. It is difficult to uniformly crimp the outer peripheral surface 22c of the sleeve 22 and the inner peripheral surface 23c of the inner surface resin-lined steel pipe 23 at all contact surfaces due to the relationship, concentricity, surface condition, etc. The fluid in the resin-lined steel pipe 23 leaks from this gap, corrodes the metal exposed surface 23d at the pipe end of the inner resin-lined steel pipe 23, and the rust caused by this corrosion flows into the inner resin-lined steel pipe 23. Therefore, there is a problem that red water is generated.

Further, the sealing between the main body 21 and the sleeve 22 is maintained by the screw connection between the female screw portion 21b of the main body 21 and the male screw portion 22a of the sleeve 22. Although the threaded portion 22a is tightly screwed into the incompletely threaded portion at the end of the threaded portion 21b for tight sealing, this method is not always perfect. In addition, a sealant may be used for the screw connection part, but the seal may be incomplete due to the application state of the sealant or the runoff of the sealant due to long-term use. For this reason, the fluid in the main body 21 leaks out between the female threaded portion 21b and the male threaded portion 22a, corrodes the metal exposed surface 23d at the pipe end of the inner resin lining steel pipe 23, and further, the rust generated by this corrosion is generated. There is a problem that it flows into the main body 21 to generate red water.

[0007]

[Problems to be solved by the device]

 The present invention is intended to solve the problems of the conventional pipe end anticorrosion structure as described above, and completely eliminates the rust at the pipe end of the inner surface resin lined steel pipe and the red water generated thereby. To prevent this, a pipe end anticorrosion structure is provided at the pipe connection end such as a valve or pipe joint.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the pipe end anticorrosion structure of the present invention is provided on the pipe connection end of the main body, and the outer peripheral surface of the sleeve part having the collar-shaped male screw part screwed to the screw part at the inner part. Install an inner surface resin lining that is screwed into the female threaded portion in the annular groove provided on the inner surface of the steel pipe with a seal ring that is oblong in cross section and is made of an elastic material such as rubber that seals between the inner peripheral surface of the steel pipe. I made it up.

In this case, the horizontally elongated oval seal ring is provided with an arbitrary number of annular projections that make sealing contact with the inner peripheral surface of the inner resin lining steel pipe and an arbitrary number of backup annular rings on the inner peripheral surface of the seal ring. A protrusion may be provided, and an annular lip may be provided adjacent to one side or both sides of the annular groove so as to be pressed against the inner peripheral surface of the inner surface resin lined steel pipe. Furthermore, the main body may be a main body of a valve such as a gate valve or a globe valve, or a main body of a pipe joint such as a socket or an elbow.

In addition, an inner resin liner screwed onto the female threaded portion on the outer peripheral surface of the body portion of the sleeve, which is provided at the pipe connection end portion of the main body It has a structure that seals between the inner peripheral surface of the steel pipe and the inner end portion of the sleeve is formed so as to sealingly abut on the stepped portion provided at the innermost portion of the female screw portion of the main body. .

In this case, the inner end portion of the sleeve may be a conical surface slightly recessed toward the center, the step portion of the main body may be an annular flat surface, and the outer peripheral surface of the body portion of the sleeve may be The structure for sealing between the inner peripheral surface of the inner surface resin-lined steel pipe and the inner peripheral surface is preferably the structure described above. Furthermore, the main body may be the main body of a valve such as a gate valve or a globe valve, or the main body of a pipe joint such as a socket or an elbow.

[0012]

In the pipe end anticorrosion structure of the present invention, first, a seal ring having an oblong cross section formed of an elastic material such as rubber is attached to an annular groove provided on the outer peripheral surface of the body of the sleeve. Since the sleeve and the inner surface of the resin lined steel pipe are hermetically sealed, there may be considerable problems such as the diametrical relationship between the outer surface of the sleeve and the inner surface of the inner surface of the resin lined steel pipe, concentricity, and surface condition. Even if there is, it can be sealed. In particular, since the cross section of the sealing ring is almost oblong, it has a larger cross-sectional area than the O-ring, which has a circular cross section, and is durable and has a large amount of deformation, and has a wider contact surface with the sleeve and the inner surface resin-lined steel pipe. So the seal is reliable. Also, since the seal ring has a horizontally long oval cross-section, it does not twist when connecting to the sleeve or when screwing the inner surface resin lined steel pipe into this pipe connection end, and the mounting is reliable and damage is prevented. Never.

Further, as described above, since the seal ring has the cross section of the oblong oval shape and does not twist, the seal ring can be provided with any number of annular protrusions for sealing the inner peripheral surface of the inner surface resin-lined steel pipe. , Which makes the seal more secure. Furthermore, the annular lips provided adjacent to one side or both sides of the annular groove directly contact the inner coating layer of the resin-lined steel pipe by pressure contact or by overturning deformation to support the seal of the seal ring. , Hold and protect the seal ring. In addition, if this pipe end anticorrosion structure is provided on valves such as gate valves, globe valves, etc. made of corrosion-resistant materials such as stainless steel, bronze, etc. or pipe joint bodies such as sockets, elbows, etc. The valves and pipe fittings of the above can be connected to the inner resin lined steel pipe to prevent corrosion of the pipe end and prevent the generation of red water.

Next, since the inner end portion of the sleeve is brought into sealing contact with the stepped portion provided at the innermost portion of the female screw portion of the main body, it is possible to reliably seal between the sleeve and the main body. . In this case, if the inner end portion of the sleeve is formed into a conical surface slightly recessed toward the center and the step portion of the main body is formed into an annular flat surface, the contact between the two becomes extremely strong at the outer peripheral portion, and the seal becomes reliable. Further, if the structure for sealing between the outer peripheral surface of the sleeve and the inner surface resin-lined steel pipe is the structure described above, both the sleeve and the main body and the sleeve and the inner surface resin-lined steel pipe can be reliably sealed. It is possible to prevent corrosion of the pipe end of the inner surface resin lining steel pipe, and there is no generation of red water.

Further, this pipe end anticorrosion structure is provided on a valve such as a gate valve or a globe valve, which is made of a corrosion resistant material such as stainless steel or bronze, or which is internally lined, or a body of a pipe joint such as a socket or an elbow. Moreover, these valves and pipe joints can be connected to the inner surface resin-lined steel pipe to prevent corrosion of the pipe end and to more reliably prevent the generation of red water.

[0016]

【Example】

 An embodiment of the pipe end anticorrosion structure of the present invention will be described with reference to the drawings. 1 is a vertical sectional view of a gate valve provided with an embodiment of a pipe end anticorrosion structure of the present invention, FIG. 2 is a vertical sectional view of a similar socket, and FIG. 3 is a partially enlarged vertical sectional view of FIG. . 1 to 3, 1 is a main body of a gate valve or a socket, 2 is a sleeve, 3 is an inner resin lined steel pipe, and 4 is a seal ring. Reference numeral 1a denotes a pipe connecting end portion provided on both sides of the main body 1. The pipe connecting end portion 1a is provided with a female screw portion 1b. The female screw portion 1b is provided on the inner surface resin-lined steel pipe 3. The threaded portion 3a is screwed in, and 3b is a coating layer of the inner surface resin lined steel pipe 3. Further, the sleeve 2 is provided with a collar-shaped threaded portion 2a, and this beveled portion 2a is screwed to the female threaded portion 1b of the main body 1 at the inner portion.

The outer peripheral surface 2c of the body portion 2b of the sleeve 2 is provided with an annular groove 2d and annular lips 2e and 2f adjacent to both sides of the annular groove 2d. The annular groove 2d has a cross section as shown in FIG. A horizontally elongated oval rubber seal ring 4 is mounted, and the elastic force of the seal ring 4 seals between the annular groove 2c of the sleeve 2 and the covering layer 3b of the inner surface resin-lined steel pipe 3. There is. 4 and 5 are enlarged partial cross-sectional views showing another embodiment of the seal ring 4 used in the pipe end anticorrosion structure of the present invention. The seal ring 4 shown in FIG. 4 includes an inner resin lined steel pipe. One annular protrusion 4a that is in sealing contact with the inner peripheral surface 3c of the seal 3 is provided, and the seal ring 4 shown in FIG. 5 is provided with two similar annular protrusions 4a. Moreover, the inner peripheral surface of the seal ring 4 is provided with one or two backup annular protrusions 4b.

As shown in FIG. 3, the inner end portion 2g of the sleeve 2 has a conical surface 2h that is slightly inclined toward the center and is recessed, and is located at the innermost portion of the female screw portion 1b of the main body 1. It is in sealing contact with the annular plane of the provided step 1c. Although the sleeve 2 is made of synthetic resin, it may be made of a corrosion resistant material such as stainless steel or bronze.

Next, the operation will be described based on the embodiment of the pipe end anticorrosion structure of the present invention shown in FIGS. 1 to 3. First, a seal ring 4 made of rubber and having a substantially oblong cross section, which is mounted in an annular groove 2d provided on the outer peripheral surface 2c of the body portion 2b of the sleeve 2, connects the sleeve 2 and the inner surface resin lining steel pipe 3 to each other. Since it is hermetically sealed, the outer peripheral surface 2c of the sleeve 2 and the inner surface 3c of the coating layer 3b of the resin-lined steel pipe 3 have a diametrical relationship, concentricity, surface condition, etc. can do. In particular, since the cross section of the seal ring is almost oblong, it has a larger cross-sectional area than the O-ring with a circular cross section and is durable and has a large amount of deformation, and has a wider contact surface with the sleeve 2 and the inner resin lining steel pipe 3. Because it has, the seal is sure. Further, since the seal ring 4 has a horizontally long oval cross section, it does not twist when mounted on the sleeve 2 or when the inner surface resin-lined steel pipe 3 is screwed into the pipe connection end 1a to be connected, and thus the seal ring 4 can be mounted easily. Reliable and not damaged.

As described above, the seal ring 4 has a horizontally elongated cross section and does not twist. Therefore, the seal ring 4 is provided with an annular protrusion 4a that is closely attached to the inner peripheral surface 3c of the inner resin lined steel pipe 3. Any number may be provided as shown in the partial cross-sectional view of FIG. 4 or 5, which further enhances the seal. Further, the annular lips 2e, 2f provided on one side of the annular groove 2d or adjacent to both sides as in the embodiment are directly or laterally pressure welded to the coating layer 3b on the inner surface of the inner resin lining steel pipe 3. Then, the seal of the seal ring 4 is backed up, and the seal ring 4 is held and protected.

Next, since the inner end portion 2g of the sleeve 2 is in sealing contact with the step portion 1c provided at the innermost portion of the female screw portion 1b of the main body 1, the gap between the sleeve 2 and the main body 1 is surely secured. Seal it. In the illustrated embodiment, the inner end portion 2g of the sleeve 2 is slightly inclined toward the center to form a concave conical surface 2h, and the step portion 1c of the main body 1 is an annular flat surface. The part is extremely strong and the seal is more reliable. In this way, both the sleeve 2 and the main body 1 and the sleeve 2 and the inner surface resin lining steel pipe 3 are reliably sealed, so that the metal exposed surface of the pipe end 3d of the inner surface resin lining steel pipe 3 is exposed. Does not come into contact with the fluid inside the pipe, the pipe end does not corrode, and red water does not occur.

Further, as shown in FIGS. 1 and 2, the pipe end anticorrosion structure of the present invention is made of a corrosion resistant material such as stainless steel or bronze, or is internally lined such as a gate valve or a globe valve. When installed in the main body 1 of pipe fittings such as sockets and elbows, these valves and pipe fittings can be connected to the inner resin lined steel pipe 3 to prevent corrosion of the pipe ends and prevent the generation of red water. .

[0023]

[Effect of device]

 As described above, in the pipe end anticorrosion structure of the present invention, the seal between the sleeve and the inner surface resin lined steel pipe is performed by using the seal ring formed of an elastic material such as rubber, and the seal ring has a cross section. Since it is almost oblong in shape and is not twisted during mounting and piping, the seal is reliable and the seal ring is less likely to be damaged. A highly reliable seal can be made between the inner surface of the resin lined steel pipe and its reliability is high. In addition, the sleeve and the body are sealed by sealingly abutting them, and the abutment surface of the sleeve is a conical surface slightly recessed toward the center, and the abutment surface of the body is an annular flat surface, and the outer peripheral portion Since it is made to abut strongly with, the seal is reliable. Since the seal is reliably sealed between the sleeve and the inner surface resin-lined steel pipe and between the sleeve and the main body, the pipe ends of the inner surface resin-lined steel pipe do not come into contact with the fluid in the pipe and corrode, and therefore red water is generated. Can be completely prevented. A pipe system in which a valve, pipe joint, etc. having such a pipe end anticorrosion structure is connected to an inner resin lined steel pipe has no possibility of generating red water.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a gate valve provided with an embodiment of a pipe end anticorrosion structure of the present invention.

FIG. 2 is a vertical sectional view of a socket provided with an embodiment of a pipe end anticorrosion structure of the present invention.

3 is a partially enlarged vertical sectional view of FIG.

FIG. 4 is a partial cross-sectional view showing another embodiment of the seal ring of the pipe end anticorrosion structure of the present invention.

FIG. 5 is a partial cross-sectional view showing another embodiment of the seal ring of the pipe end anticorrosion structure of the present invention.

FIG. 6 is a partial vertical sectional view showing an example of a gate valve provided with a conventional pipe end anticorrosion structure.

[Explanation of symbols]

 1 Main Body 1a Pipe Connection End 1b Female Thread 1c Step 2 Sleeve 2a Male Thread 2b Body 2c Outer Surface 2d Annular Grooves 2e, 2f Lip 2g Inner End 3 Inner Surface Resin Lining Steel Pipe 3c Inner Surface 4 Seal Ring 4a Annular protrusion 4b annular protrusion

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masachika Inoue One day at 153 Tajime-cho, Kishiwada-shi, Osaka

Claims (10)

[Scope of utility model registration request] 1. An internal groove is provided in an outer peripheral surface of a body of a sleeve having a collar-shaped male threaded portion which is threadedly connected to a threaded portion at a pipe connection end of a main body. A pipe end anticorrosion structure, characterized in that a seal ring having an oblong cross section formed of an elastic material such as rubber for sealing a gap between the inner surface of a resin-lined steel pipe and a resin-lined steel pipe screwed into is attached. 2. The laterally elongated oval seal ring is provided with an arbitrary number of annular projections that come into sealing contact with the inner peripheral surface of the inner resin lined steel pipe and an arbitrary number of backup annular projections on the inner peripheral surface of the seal ring. It is provided, It is characterized by the above-mentioned.
The described pipe end anti-corrosion structure. 3. An annular lip provided adjacent to one side or both sides of the annular groove so as to be in pressure contact with the inner peripheral surface of the inner surface resin-lined steel pipe. Pipe end anti-corrosion structure. 4. The pipe end anticorrosion structure according to claim 1, wherein the main body is a main body of a valve such as a gate valve or a globe valve. 5. The pipe end anticorrosion structure according to claim 1, wherein the main body is a main body of a pipe joint such as a socket or an elbow. 6. An inner surface resin-lined steel pipe screwed onto the female screw portion on the outer peripheral surface of the body portion of a sleeve having a collar-shaped male screw portion which is provided at the pipe connecting end portion of the main body and is threadedly coupled to the screw portion at the inner portion. Has a structure that seals between the inner peripheral surface of the sleeve and the inner peripheral surface of the sleeve, and the inner end portion of the sleeve is formed so as to sealingly abut on a stepped portion provided at the innermost portion of the female screw portion of the main body. Characteristic pipe end anti-corrosion structure. 7. The pipe end anticorrosion structure according to claim 6, wherein the inner end of the sleeve is a conical surface slightly recessed toward the center, and the step of the body is an annular flat surface. . 8. A structure for sealing between the outer peripheral surface of the body portion of the sleeve and the inner peripheral surface of the inner surface resin-lined steel pipe is the structure according to any one of claims 1 to 3. The pipe end anticorrosion structure according to claim 6 or 7. 9. The pipe end anticorrosion structure according to claim 6, wherein the main body is a main body of a valve such as a gate valve or a globe valve. 10. The pipe end anticorrosion structure according to claim 6, wherein the main body is a main body of a pipe joint such as a socket and an elbow.