JP2577540Y2 - Pipe end corrosion protection structure - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a pipe end anticorrosion structure,
In particular, the inner resin-lined steel pipes used for water supply and hot water supply pipes are corroded and rusted at pipe ends connected to valves, pipe joints, etc. The present invention relates to a pipe end corrosion protection structure provided at a pipe connection end of a main body.

[0002]

2. Description of the Related Art In order to prevent rust from being generated in pipes for water supply, hot water supply, etc., and to mix the rust 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. became. However, there has been a problem that a cut section of a steel pipe that is not resin-lined is exposed to water at a pipe end connected to a valve, a pipe joint, or the like, and rusts there, and red water is still generated. For this reason, the pipe connection end portion of the main body such as a valve or a pipe joint has a pipe end corrosion prevention structure in which the cut section of the steel pipe of the pipe is not exposed to water.

FIG. 6 is a partial longitudinal sectional view showing a conventional example of a gate valve in which a pipe connection end of a main body has a pipe end corrosion prevention 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 a disc and a stem of the valve. 21a is a pipe connection end of the main body 21,
An internal thread 21b is provided at the pipe connection end 21a, and an internal resin lining steel pipe 23 is provided on the internal thread 21b.
Is screwed in. 23
b is a coating layer of the inner resin-lined steel pipe 23.

[0004] A flange-shaped external thread portion 22a formed on the sleeve 22 is screwed into the female thread portion 21b of the main body 21, and the main body 21 and the sleeve 22 are connected to each other by a screw connection between the external thread portion 22a and the internal thread portion 21b. The outer periphery 22c of the body 22b of the sleeve 22 is pressed against the inner periphery 23c of the coating layer 23b of the inner resin-lined steel pipe 23 to seal the space between the inner resin lining 23 and the sleeve 22. I have. For this reason, the fluid in 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, and therefore, the pipe connection end 21a of the main body 21 is It has a pipe end anticorrosion structure.

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

The seal between the main body 21 and the sleeve 22 is maintained by a screw connection between the female thread 21b of the main body 21 and the external thread 22a of the sleeve 22, and in general, the female is provided. Although the screw portion 22a is tightly screwed into the incomplete thread portion at the end of cutting of the screw portion 21b, the screw portion 22b is tightly sealed. However, this method is not always perfect. Although a sealant may be used for the threaded joint, the seal may be incomplete due to the state of application of the sealant or the loss of the sealant due to long-term use. For this reason, the fluid in the main body 21 is
a, the metal exposed surface 23d at the end of the inner resin-lined steel pipe 23 is corroded, and the rust generated by the corrosion flows into the main body 21 to generate red water. doing.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the conventional pipe end anticorrosion structure, and is intended to solve the problem of the occurrence of rust at the pipe end of an inner resin-lined steel pipe. It is an object of the present invention to provide a pipe end corrosion prevention structure provided at a pipe connection end of a valve, a pipe joint, or the like in order to completely prevent red water generated thereby.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a pipe end anticorrosion structure of the present invention is provided at a pipe connection end of a main body.
A collar provided at the end of the sleeve at the back of the threaded part
The external thread of this sleeve is connected by screwing
The inner surface screwed into the female thread part in the annular groove formed in
Sealing for sealing between the inner peripheral surface of the resin-lined steel pipe
The sleeve, and form the inner end surface of the sleeve into a conical surface.
The inner end surface of this conical surface to the innermost part of the female thread of the main body.
So that it abuts against the annular flat surface of the step provided in
Was .

[0009] In this case, adjacent to one side or both sides of the annular groove,
To be pressed against the inner peripheral surface of the inner resin lining steel pipe
Lip is provided.

Further, the main body includes a gate valve and a globe bar.
This is the main body of a valve such as a lube.

In addition, the main body is a tube such as a socket or an elbow.
It is the body of the joint.

[0012]

[Action] pipe end anticorrosive structure of the present invention, since sealed by a seal ring formed of an elastic material such as rubber which is mounted in an annular groove provided in the body portion outer peripheral surface of the sleeves, scan
Reliable seal between the sleeve and the inner resin-lined steel pipe
It is.

Further, an annular lip provided adjacent to one side or both sides of the annular groove directly presses or sideways deforms and presses against the coating layer on the inner surface of the inner resin-lined steel pipe to back up the seal of the seal ring. In addition, the seal ring is held and protected. In addition, when this pipe end corrosion-resistant structure is made of a corrosion-resistant material such as stainless steel or bronze , or provided on a valve such as a gate valve or a globe valve lined with an inner lining , or a socket or a body of a pipe joint such as an elbow, such a structure is provided. The valve and the pipe joint can be connected to the inner resin-lined steel pipe to prevent corrosion of the pipe end and to prevent generation of red water.

Next, the conical inner end surface of the sleeve is brought into line contact with the step provided at the innermost portion of the internal thread portion of the main body in a line contact state.
Since the surfaces are sealed to abut against each other, the space between the sleeve and the main body can be reliably sealed. In this case, the contact portions of the two contact in a line contact state and are extremely strong.
It becomes the end face seal, and the seal becomes reliable. Also mentioned earlier
It was by sealing between the outer peripheral surface and the inner surface plastic lined steel pipe sleeve by the structure, because it is possible to reliably seal both between and between the sleeve and the inner surface plastic lined steel pipe between the sleeve and the body, it is possible to prevent corrosion of the pipe end of the inner surface plastic lined steel pipe, is red water
There is no possibility that this will occur.

Further, the pipe end anticorrosion structure is made of stainless steel,
Gate valves and glove valves made of corrosion-resistant materials such as bronze , or provided inside the body of pipe fittings such as sockets, elbows, etc., when these valves and pipe fittings are installed on the inner resin-lined steel pipe The connection can prevent corrosion of the pipe end, and can more reliably prevent the generation of red water.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a pipe end anticorrosion structure according to the present invention. FIG. 1 is a longitudinal sectional view of a gate valve provided with one embodiment of a pipe end anticorrosion structure of the present invention, FIG. 2 is a longitudinal sectional view of a similar socket, and FIG. 3 is a partially enlarged longitudinal sectional view of FIG. . 1 to 3, reference numeral 1 denotes a gate valve or socket main body, 2 denotes a sleeve, 3 denotes an inner surface resin-lined steel pipe, and 4 denotes a seal ring. 1a is the body 1
A pipe connection end portions provided on opposite sides of the female screw portion 1b is provided we are in the pipe connection end 1a, the female screw portion 1b
Male thread 3a provided on the inner surface resin-lined steel pipe 3
3b is an inner resin-lined steel pipe 3
Is a coating layer. Further, the sleeve 2 is provided with a flange-shaped threaded portion 2a, and the male threaded portion 2a is screw-coupled to the female threaded portion 1b of the main body 1 at the back.

An annular groove 2d is formed on the outer peripheral surface 2c of the body 2b of the sleeve 2 and annular lips 2e and 2f are provided adjacent to both sides thereof.
A rubber seal ring 4 having a substantially oblong cross section as shown in FIG. 3 is mounted in the annular groove 2 d, and the elastic force of the seal ring 4 causes the annular shape of the sleeve 2. The space between the groove 2c and the coating layer 3b of the inner resin-lined steel pipe 3 is sealed. 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. 5 is provided with one annular projection 4a that comes into sealing contact with the inner peripheral surface 3c of FIG.
The seal ring 4 shown in FIG.
a is provided. Moreover, one or two backup annular projections 4b are provided on the inner peripheral surface of the seal ring 4.

As shown in FIG. 3, the inner end surface 2g of the sleeve 2 has a conical surface 2h that is slightly inclined toward the center and is concave.
, And hermetically contacts the annular flat surface of the step portion 1c provided at the innermost portion of the female screw portion 1b of the main body 1. The sleeve 2 is made of a synthetic resin, but 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. First, the sleeve 2 and the inner resin-lined steel pipe 3 are sealed by a rubber-made seal ring 4 having a substantially oblong cross section which is fitted in an annular groove 2d provided on an outer peripheral surface 2c of a body 2b of the body 2b of the sleeve 2. Therefore, even if there is a considerable defect in the relation between the outer peripheral surface 2c of the sleeve 2 and the inner peripheral surface 3c of the coating layer 3b of the inner resin lining steel pipe 3, the degree of concentricity, the surface state, etc., sealing is performed. be able to. In particular, since the cross-section of the seal ring is substantially oblong and oblong, the cross-sectional area is larger than that of the O-ring having a circular cross-section, and the cross-sectional area is durable and has a large amount of deformation. Because it has, the seal is reliable. Also, since the cross section of the seal ring 4 is oblong and oblong, when it is attached to the sleeve 2 or when the inner resin lining steel pipe 3 is screwed and connected to the pipe connection end 1a,
No twisting, secure mounting and no damage.

Further, since the seal ring 4 has a horizontally long and oblong cross section and does not twist as described above, the annular projection 4a for bringing the seal ring 4 into close contact with the inner peripheral surface 3c of the inner resin-lined steel pipe 3 is shown in FIG. Any number can be provided as shown in the partial cross-sectional view of FIG. 4 or FIG. 5, which makes the seal more secure. Further, annular lips 2e, 2f provided adjacent to one side of the annular groove 2d or both sides as in the embodiment are directly pressed or laterally pressed against the coating layer 3b on the inner surface of the inner resin-lined steel pipe 3 to seal. The seal of the ring 4 is backed up and the seal ring 4 is held and protected.

Next, since the inner end surface 2g of the sleeve 2 is in sealing contact with the stepped portion 1c provided at the innermost portion of the internal thread portion 1b of the main body 1, the space between the sleeve 2 and the main body 1 is ensured. Seal. In the illustrated embodiment, the inner end face 2 of the sleeve 2
Since g is slightly inclined toward the center to form a concave conical surface 2h, and the step portion 1c of the main body 1 is formed into a ring-shaped flat surface, the contact between the two becomes extremely strong at the outer peripheral portion, and the sealing is more reliable. As described above, since both the space between the sleeve 2 and the main body 1 and the space between the sleeve 2 and the inner surface resin-lined steel pipe 3 are securely sealed, the metal exposed surface of the pipe end 3d of the inner surface resin-lined steel pipe 3 is reduced. There is no contact with the fluid in the pipe, the pipe end does not corrode, and no red water is generated.

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 internally lined with a valve such as a gate valve or a globe valve. , Sockets, elbows, etc., provided on the main body 1 of the pipe joint, these valves and the pipe joint are connected to the inner surface resin-lined steel pipe 3 to prevent corrosion of the pipe end,
The generation of red water can be prevented.

[0023]

As has been described above devised], pipe end anticorrosive structure of the present invention, the re-seal the sealing ring formed of an elastic material such as rubber between the sleeve and the inner surface plastic lined steel pipe
The seal is secure and the seal ring is not easily damaged because it is installed in the annular groove having a gap. The gap can be sealed very reliably, and its reliability is high. In addition, the seal between the sleeve and the main body is performed by sealingly contacting the two,
The inner end surface of the sleeve is a conical surface, and the contact surface of the main body is an annular flat
And the conical inner end face and the step of the annular plane are lined
Seal the end face in the contact state to make strong contact at the site
As a result, the seal is secure and the sleeve shaft
The end face is sealed by absorbing the shake. Since the reliably tight seal between the two and between the sleeve and the body of the sleeve and the inner surface plastic lined steel pipe, without the pipe end of the inner surface plastic lined steel pipe is corroded touch the fluid inside the tube, this end The generation of red water can be completely prevented. A piping system in which a valve, a pipe joint, or the like having such a pipe end corrosion prevention structure is connected to an inner resin-lined steel pipe has no possibility of generating red water.

[Brief description of the drawings]

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

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

FIG. 3 is a partially enlarged longitudinal sectional view of FIG. 1;

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 corrosion protection structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body 1a Pipe connection end part 1b Female thread part 1c Step part 2 Sleeve 2a Male thread part 2b Body part 2c Outer peripheral surface 2d Annular groove 2e, 2f Lip 2g Inner end surface 3 Inner resin lining steel pipe 3c Inner peripheral surface 4 Seal ring 4a Annular projection 4b Annular projection

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masachika Inoue 153, Tajimecho, Kishiwada-shi, Osaka Nippon Steel Pipe Fitting Co., Ltd. (56) References Japanese Utility Model 2-140089 (JP, U) Japanese Utility Model 2 −119585 (JP, U) Japanese Utility Model Application Hei 4-80992 (JP, U) (58) Fields surveyed (Int.Cl. ⁶ , DB name) F16L 15/04 F16L 58/18

Claims (4)

(57) [Scope of request for utility model registration] 1. A flange-shaped thread provided at the tip of a sleeve is provided at the back of the thread to be provided at the pipe connection end of the main body.
An annular ring formed on the outer peripheral surface of the body of this sleeve by screw connection
Internal resin lining screwed into the female thread in the groove
Attach a seal ring to seal between the inner peripheral surface of the steel pipe
At the same time, the inner end surface of the sleeve is formed into a conical surface,
The flat inner end surface is set at the step provided at the
A pipe end anticorrosion structure characterized in that it comes into sealing contact with the annular flat surface of the part . 2. An inner surface tree on one or both sides of the annular groove.
An annular lip that presses against the inner peripheral surface of the grease-lined steel pipe
The pipe end anticorrosion structure according to claim 1 provided . 3. The apparatus according to claim 2, wherein the main body is a gate valve, a globe.
The valve according to claim 1 or 2, which is a main body of a valve such as a valve.
Pipe end corrosion protection structure. 4. The main body is a tube such as a socket, an elbow, etc.
The pipe end anticorrosion structure according to claim 1 or 2, which is a main body of the joint.
Build.