JP3418256B2 - Anticorrosion ball valve - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an anticorrosion ball valve.

[0002]

2. Description of the Related Art Conventionally, as an anticorrosion ball valve to which a lining steel pipe is connected, there is one described in JP-A-2-134479. That is, as shown in FIG. 5, between a valve box b having a female screw portion a to which a connected pipe (lining steel pipe) is screwed at an end opening, and the female screw portion a (for fitting the connected pipe ) A resin anticorrosion core e having a cylindrical portion d for forming the annular gap portion c.

The connected pipe is generally composed of a metal pipe body and an anticorrosive resin layer covering the inner surface of the pipe body, and the metal pipe body is in direct contact with the inner peripheral surface of the valve box b. It was

The metal tube body is made of, for example, carbon steel or cast iron, and the valve box is made of, for example, gun metal.

[0005]

Therefore, in the above-mentioned prior art, a corrosion current (galvanic current) is generated between the valve box and the pipe to be connected due to the contact of different metals, and the pipe of the pipe to be connected is generated. A part of the main body was corroded and sometimes leaked water.

Therefore, an object of the present invention is to provide an anticorrosion ball valve which can prevent corrosion due to dissimilar metals and can be safely used for a long period of time.

[0007]

In order to achieve the above-mentioned object, an anticorrosion ball valve according to the present invention comprises a resin anticorrosion core having a tubular portion to which an end of a pipe to be connected is fitted. In an anticorrosion ball valve provided inside a cylindrical metal valve box, a tubular metal insert member having an internal thread portion with an internal thread portion to which the male thread end portion of the connected pipe is screwed Through an insulating layer having an insulating property, fixed to the inner peripheral surface of the metal valve box ,
Can rotate the ball closely to the ball inside the metal valve box
It is common to provide a bulge to support the core at the base end of the anticorrosion core.
The inner collar part closely contacting the bulging part of the anticorrosion core with
It is provided at the end of the valve member inside the valve box .

Further , a tubular portion to which the end of the connected pipe is fitted.
A resin anticorrosion core with a
In the provided anticorrosion ball valve, the male thread at the end of the connected pipe
A cylindrical metal cable having an internal thread portion on the inner peripheral surface, with which the threaded portion is screwed.
Insert member through an insulating layer having electrical insulation.
Adheres to the inner surface of the metal valve box, and
The outer surface of the bulging portion at the base end of the core and the metal insert portion
Packing is provided between the end surface of the material and the inner peripheral surface of the metal valve box.
Is installed.

It is also preferable that the pipe to be connected is composed of a metal pipe main body and an anticorrosive resin layer covering the inner surface of the pipe main body, and the insert member is made of the same material as the metal pipe main body of the connection pipe. .

Further, the metal valve box comprises a main body having a threaded portion at the end opening, and a nut member screwed to the threaded portion of the main body and having an insert member fixedly inserted therein. There are cases.

[0011] or provided small protrusion on the outer peripheral surface of the cylindrical portion of the corrosion protection core, yet preferred or fitted a seal ring to the cylindrical portion of the corrosion protection core.

Further , when the insulating layer is made of an adhesive having an electrical insulating property for adhering the insert member to the inner peripheral surface of the valve box, or when the insulating layer is formed by vulcanization baking. It may consist of a rubber layer having.

[0013]

Since the insert member is fixed to the inner peripheral surface of the valve box through the electrically insulating insulating layer, the male screw end portion of the pipe to be connected is formed with the female screw portion of the cylindrical metal insert member. Even if the pipe to be connected is connected by screwing the pipe to the pipe, the pipe to be connected and the valve box are insulated from each other, and a corrosion current due to a dissimilar metal does not flow between them.

Further, if the insert member is made of the same material as the metallic pipe body of the pipe to be connected, no corrosion current due to different metals flows between the insert member and the pipe body of the pipe to be connected.

When the metal valve box is composed of the main body and the nut member, the anticorrosion ball valve can be easily assembled,
In the case where the insert member is provided with the inner flange portion, the inner flange portion is brought into close contact with the bulging portion of the anticorrosion core, so that the space between the anticorrosion core and the insert member can be sealed.

If the anticorrosion core is separated into the core body and the support, the anticorrosion core can be easily manufactured and the anticorrosion core can be easily attached to the valve box.

Further, if a small ridge is provided on the outer peripheral surface of the tubular portion of the anticorrosion core or a seal ring is externally fitted to the tubular portion of the anticorrosion core, the water tightness between the pipe to be connected and the anticorrosion core can be obtained. If the packing is interposed between the outer surface of the bulging portion at the base end of the anticorrosion core, the end surface of the insert member, and the inner peripheral surface of the valve box, the anticorrosion core, insert member, and valve box The watertightness between the inner surface and the inner surface of the

In the case where the insulating layer is made of an adhesive, if the adhesive is interposed between the outer peripheral surface of the insert member and the inner peripheral surface of the valve box, the adhesive is solidified to easily form the insulating layer. can do. Further, in the case where the insulating layer is formed by vulcanization baking, unvulcanized rubber is interposed (injected) between the outer peripheral surface of the insert member and the inner peripheral surface of the valve box. By vulcanizing, the insulating layer can be easily formed.

[0019]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

FIG. 1 shows an anticorrosion ball valve according to the present invention,
This valve has a cylindrical portion 2 to which the end portion 1a of the connected pipe 1 is fitted.
The resin anticorrosion core 3 having the above is provided inside a cylindrical metal valve box 4.

The pipe 1 to be connected is composed of a metal pipe body 5 and an anticorrosion resin layer 6 covering the inner surface of the metal pipe body 5, and an end male screw portion 7 is formed. The metal pipe body 5 is made of carbon steel, cast iron or the like, and the anticorrosion resin layer 6 is made of hard vinyl chloride, polyethylene, epoxy or the like.

Thus, the valve box 4 is provided with a tubular main body 9 having threaded portions 8 and 8 at the end opening and a nut member 10 screwed onto the threaded portion 8 of the main body 9.

A through hole 11 is formed in the main body 9, and a valve rod 13 connected to a ball 12 arranged in the valve box 4 is inserted into the through hole 11. An operating lever 14 is connected to the valve rod 13, and the ball 12 is rotated through the valve rod 13 by operating the lever 14. The rotation of the ball 12 opens and closes the valve.

The nut member 10 is made of a cylindrical body having a cutout portion 15 on the outer peripheral surface thereof.
A screw portion 16 that is screwed into the screw portion 8 is provided.

Therefore, as shown in FIG. 1, if the threaded portion 16 of the nut member 10 is screwed into the threaded portion 8 of the body 9 to integrate the body 9 and the nut member 10, the nut member 10 is cut off. The end portion 17 of the main body 9 is fitted into the notch portion 15 so that the outer peripheral surface of the main body 9 and the outer peripheral surface of the nut member 10 are continuous.

The anticorrosion core 3 includes the above-mentioned tubular portion 2 and
And a bulge portion 18 provided at the base end portion. Bulge 18
Is for rotatably supporting the ball 12 inside the valve box 4, and a cutout portion is provided at an outer end portion of the inner peripheral surface thereof, and the ball 12 is provided on the cutout surface 19 of the cutout portion. Make sliding contact. The anticorrosion core 3 is made of, for example, a resin such as PTFE.

Thus, the tubular metal insert member 20
Is fixed to the valve box 4, specifically, the nut member 10 via an insulating layer 21 having an electrically insulating property. Insert member 20
Has an internal thread portion 22 formed on its inner peripheral surface.
The threaded portion 7 of the pipe 1 to be connected is screwed into the pipe 22.

In this case, the material of the insert member 20 is preferably the same as the material of the pipe body 5 of the pipe 1 to be connected.
For example, the insert member 20 and the pipe body 5 are made of carbon steel or cast iron.

An inner flange portion 23 is provided at the base end portion of the insert member 20 (that is, the end portion on the inner side of the valve box 4),
The inner collar 23 is in close contact with the bulging portion 18 of the anticorrosion core 3. That is, the inner end surface 25 of the inner flange portion 23 is in close contact with the contact surface 24 formed of the outer end surface of the bulging portion 18 or the outer peripheral surface of the base portion of the tubular portion 2.

Therefore, the threaded portion 7 of the connected pipe 1 is screwed into the female threaded portion 22 of the insert member 20, and the end portion 1a of the connected pipe 1 is fitted onto the tubular portion 2 of the anticorrosion core 3. For example, the tubular portion 2 of the anticorrosion core 3 comes into close contact with the anticorrosion resin layer 6 of the connected pipe 1, and the connected pipe 1 is connected to this valve.

At this time, since the bulging portion 18 of the anticorrosion core 3 and the inner flange portion 23 of the insert member 20 are in close contact with each other, the anticorrosion core 3
A reliable seal can be made between the insert member 20 and the insert member 20.

Thus, the insert member 20 and the nut member
The insulating layer 21 interposed between the insulating member 21 and 10 is, for example, a solidified adhesive having an electrically insulating property such as epoxy, and the insert member 20 forms the nut member 10 in the insulating layer 21.
Stuck to.

Therefore, the insert member 20 and the valve box 4 are electrically insulated, and the valve box 4 is made of the most versatile gun metal among the copper alloys used as the material of the valve box. Even if the insert member 20 and the valve box 4 are made of different metals, no corrosion current is generated due to the contact of the different metals.

As the insulating layer 21, for example, NB
The rubber-based inclusions made of R, EPDM, CR, etc. are attached to the outer peripheral surface of the insert member 20 and the valve box 4 (that is, the nut member 1).
It may be formed by interposing it between the inner peripheral surface of 0) and fixing it with the above-mentioned adhesive.

Further, between the outer peripheral surface of the insert member 20 and the inner peripheral surface of the nut member 10 of the valve box 4, a raw rubber (for example,
(Including NBR, EPDM, CR, etc.), and then the raw rubber is vulcanized and baked to form the insulating layer 21. Also in this case, the insulating layer 21 has its outer peripheral surface closely contacted with the inner peripheral surface of the nut member 10 of the valve box 4, and its inner peripheral surface closely adhered with the outer peripheral surface of the insert member 20 so that the insert member 20 and the nut member And 10 are integrated. The insulating layer 21
May be formed by injection molding. That is, the insert member
Between the outer peripheral surface of 20 and the inner peripheral surface of the nut member 10 of the valve box 4, a resin (for example, vinyl chloride, polyethylene, polybutene,
The insulating layer 21 may be formed by injecting (made of polyamide or the like).

Thus, the outer surface 26 of the bulging portion 18 of the anticorrosion core 3
A ring-shaped packing 30 is interposed in a gap 29 between the end surface 27 of the insert member 20 and the inner peripheral surface 28 of the valve box 4.
The packing 30 is made of, for example, a synthetic resin such as PTFE or NB.
It is made of rubber such as R, EPDM, and CR.

Therefore, the packing 30 ensures a reliable seal between the valve box 4, the insert member 20 and the anticorrosion core 3. The outer surface 26 of the bulging portion 18 is in close contact with the protrusion 32 provided on the inner peripheral surface 28 of the main body 9.

According to the anticorrosion ball valve configured as described above, if the pipes 1 and 1 to be connected are respectively screwed to the insert members 20 and 20 at both ends, the pipes 1 and 1 to be connected are connected to each other. It can be connected through an anticorrosion ball valve, and as shown in FIG. 1, the through hole 12a of the ball 12 is connected to the hole 3 of the anticorrosion core 3,3.
Corresponding to a and 3a, the anticorrosion cores 3 and 3 are connected to each other through the through holes 12a of the balls 12 to open the valve box passage 31.
Is formed, whereby the pipes 1, 1 to be connected are communicatively connected. Further, if the operation lever 14 is operated to rotate the ball 12 so that the through hole 12a of the ball 12 does not correspond to the holes 3a, 3a of the anticorrosion cores 3, 3, the holes 3a of the anticorrosion cores 3, 3 are formed. , 3a are not connected for communication, the valve box flow path 31 is closed, and the connected pipes 1, 1 are not connected for communication.

As described above, even if the connected pipe 1 is connected, the insert member 20 and the valve box 4 are insulated by the insulating layer 21, and the insert member 20 and the pipe body 5 of the connected pipe 1 are separated from each other. Since they are made of the same material, no corrosion current (galvanic current) flows between the insert member 20 and the valve body 4, and between the insert member 20 and the pipe body 5, so that corrosion is effectively prevented.

Between the outer peripheral surface of the anticorrosion core 3 and the inner peripheral surface of the end 1a of the pipe 1 to be connected, the outer surface of the bulging portion 18 of the anticorrosion core 3.
Between the inner surface 26 of the insert member 20 and the inner surface 28 of the insert member 20, etc., the fluid in the pipe, such as water, does not enter, effectively preventing the fluid in the pipe from flowing out, and at the same time, the insulating layer The fluid in the pipe does not go around to 21 and the adhesive force of the adhesive or the like is not reduced.

However, as the anticorrosion core 3, as shown in FIG. 2A, it is also preferable to provide a spiral or independent small protrusion 33 on the outer peripheral surface 2a of the tubular portion 2.

That is, when the male screw portion 7 of the pipe 1 to be connected is screwed to the female screw portion 22 of the insert member 20, the small protrusions 33 bite into the inner peripheral surface of the anticorrosion resin layer 6 of the pipe 1 to be connected. , Or the small protrusions 33 themselves are crushed. Therefore,
Due to the small protrusions 33, the outer peripheral surface of the tubular portion 2 and the connected pipe 1
The watertightness between the inner surface of the is increased.

A seal ring 34 such as an O-ring may be fitted on the tubular portion 2 of the anticorrosion core 3. That is, the tubular portion 2
A circumferential recessed groove 35 is formed on the outer peripheral surface 2a, and the seal ring 34 is fitted into the recessed groove 35.

Therefore, the seal ring 34 is interposed between the outer peripheral surface 2a of the tubular portion 2 of the anticorrosion core 3 and the inner peripheral surface of the pipe 1 to be connected to form the outer peripheral surface 2a of the tubular portion 2. The sealing effect between the inner peripheral surface of the connected pipe 1 can be enhanced.

Next, FIG. 3 shows another embodiment. In this case, a male screw portion 36 is formed on the valve box 4. That is, valve box 4
Comprises a body 9 and a nut member 10. The body 9 has a tubular portion 37 having a threaded portion 8 with which the nut member 10 is screwed on one end side and a male threaded portion 36 on the other end side. It is provided.

Therefore, in this case, the anticorrosion core 3 and the insert member 20 are provided one by one, and the annular resin for rotatably supporting the balls 12 is provided on the cylindrical portion 37 side in the valve box 4. A support 38 made of steel is attached. The support 38 has the same shape as the bulging portion 18 of the anticorrosion core 3, and the ball 12 is in sliding contact with the notch surface 39.

The right half of the valve shown in FIG. 3 is shown in FIG.
The description is omitted because it is the same as the right half.

That is, in this case, the end male screw portion 7 of the pipe 1 to be connected can be screwed to the female screw portion 22 of the insert member 20 to connect the pipe 1 to be connected to this valve, and to the male screw portion. It is possible to connect an unillustrated connected pipe having an end female screw portion.

Therefore, when the connected pipe 1 is connected, as in the case of FIG. 1 described above, corrosion is effectively prevented, and the fluid in the connected pipe 1 is effectively prevented from flowing out. Moreover, the adhesive strength of the insulating layer 21 is not reduced.

Next, FIG. 4 shows another embodiment. In this case, the anticorrosion core 3 is in close contact with the core body 40 having the cylindrical portion 2 and the support for rotatably supporting the ball 12. body
It is separated into 41 and.

That is, the core body 40 of the anticorrosion core 3 is composed of the base end boss portion 42 and the tubular portion 2, and the base end boss portion 42 is in close contact with the inner flange portion 23 of the insert member 20. Also the support
Reference numeral 41 has the same shape as the bulging portion 18 of the anticorrosion core 3 shown in FIG. 1, and the ball 12 is in sliding contact with the cutout surface 43.

Thus, the ring-shaped spacer 45 having the interposition part 44 interposed between the core body 40 of the anticorrosion core 3 and the support 41 is fixed to the valve box 4, specifically, the body 9. .
In this case, the support body 41 is fitted into the notch portion 46 of the spacer 45, and the axial center of the hole portion 41 a of the support body 41 and the hole portion 45 of the spacer 45.
The axis of a and the axis of the hole 40a of the core body 40 are aligned, and the hole diameters of the holes 41a, 40a, and 45a are substantially the same.

Therefore, also in this valve, as in the valve shown in FIG. 1, the female screw portions 22, 22 of the insert members 20, 20 at both ends are formed.
If the threaded portions 7 and 7 of the pipes 1 and 1 to be connected are screwed to the two pipes, the two pipes 1 and 1 to be connected can be connected via this anticorrosion ball valve. The box flow path 31 can be opened and closed.

Between the insert member 20 and the valve box 4,
Also, a corrosion current (galvanic current) does not flow between the insert member 20 and the pipe body 5, corrosion can be effectively prevented, and leakage of fluid in the pipe can be surely prevented.

Further, the anticorrosion core 3 includes a core body 40 and a support.
Separated from 41, it is easy to manufacture, easy to assemble, and easy to repair.

By the way, in the anticorrosion ball valve according to the present invention, the connected pipe 1 into which the material of the insert member 20 is screwed
It is possible to provide an anticorrosion ball valve that can prevent corrosion and can be connected to various types of pipes by appropriately selecting it according to the type. For example, if the insert member 20 is made of stainless steel, it is possible to connect the connected pipe whose metallic pipe body 5 is made of stainless steel.

[0057]

Since the present invention is constructed as described above,
The following effects are achieved.

Corrosion current (galvanic current) due to contact of dissimilar metals does not flow between the connected pipe 1 and the valve box 4,
Corrosion of the connected pipe 1 is effectively prevented, and water leakage can be prevented. In particular, if the insert member 20 is made of the same material as the metal pipe body 5 of the connected pipe 1, a corrosion current does not flow between the insert member 20 and the connected pipe 1, and corrosion can be reliably prevented. You can

The metal valve box 4 includes a main body 9 and a nut member.
With the structure of 10 and 10, the valve can be easily assembled, and the insert members made of different materials can be easily assembled to easily adapt to various pipe types.

If the inner flange portion 23 of the insert member 20 is in close contact with the bulging portion 18 of the anticorrosion core 3, the insert member 20
It is possible to prevent the in-tube fluid from entering between the anticorrosion core 3 and the anticorrosion core 3, and to prevent the fluid from leaking to the outside.

[0061]   On the outer peripheral surface 2a of the tubular portion 2 of the anticorrosion core 3.
Small protrusions 33 are provided, or the cylindrical portion 2 of the anticorrosion core 3 is sealed.
If the ring 34 is externally fitted, the cylindrical portion 2 of the anticorrosion core 3
Infiltration of fluid between the outer peripheral surface 2a and the inner peripheral surface of the connected pipe 1
Can be more reliably prevented, and an excellent waterproof function is issued.
Volatile.

[0062]   By inserting packing 30
The outer surface 26 of the bulge 18 of the edible core 3 and the end of the insert member 20
A reliable seal is provided between the surface 27 and the inner peripheral surface 28 of the valve box 4.
It is possible to achieve a better waterproof function.

[0063]   The insulating layer 21 is formed by solidifying the adhesive.
Then, with the outer peripheral surface of the insert member 20 and the inner peripheral surface of the valve box 4,
If an adhesive is interposed between the two, the adhesive will solidify and the insert
The insulating member 21 is formed by integrating the valve member 20 and the valve box 4.
In addition, the insulating layer 21 is formed by vulcanization baking
Then, between the outer peripheral surface of the insert member 20 and the inner peripheral surface of the valve box 4,
Raw rubber is infiltrated (interposed) in between and vulcanized and baked in this state.
If it is done, the insert member 20 and the valve box 4 will be integrated and
Since the edge layer 21 is formed, it is easy to assemble and
Be sure to insulate between the insert member 20 and the valve box 4.
You can

[Brief description of drawings]

FIG. 1 is a sectional view of an anticorrosion ball valve according to the present invention.

FIG. 2 is a cross-sectional view showing a modified example of the anticorrosion core.

FIG. 3 is a sectional view of another embodiment.

FIG. 4 is a cross-sectional view of another embodiment.

FIG. 5 is a sectional view of a conventional anticorrosion ball valve.

[Explanation of symbols]

1 Connected pipe 1a end 2 tubular parts 2a outer peripheral surface 3 Resin anticorrosion core 4 metal valve box 5 Metal tube body 6 Anticorrosion resin layer 7 End male thread 8 screw part 9 body 10 Nut member 12 balls 18 bulge 20 Insert member 21 insulating layer 22 Female thread 23 Inner collar 26 exterior 27 Edge 28 Inner surface 30 packing 33 Small ridge 34 seal ring 40 core body 41 Support

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyoshi Ohata 5-1074 Nishikiori, Tondabayashi City, Osaka Prefecture (72) Inventor Akio Hota 2-95-14 Hikino-cho, Sakai City, Osaka Prefecture (56) Reference Japanese Patent Laid-Open No. 2- 134479 (JP, A) JP-A 2-159492 (JP, A) JP-A 60-208687 (JP, A) Actually open 4-111983 (JP, U) Actually open 59-6683 (JP, U) Actually open 56-166390 (JP, U) Actually open 64-4985 (JP, U) Actually open 2-69184 (JP, U) Actually open 1-139193 (JP, U) Actually open 63-139373 (JP, U) Actual opening Sho 63-146266 (JP, U) Actual opening Sho 60-47981 (JP, U) Actual opening Sho 62-115581 (JP, U) Japanese Patent Publication 6-46077 (JP, B2) Actual Kohei 2-31668 (JP, Y2) Actual Kohei 2-337014 (JP, Y2) British Patent 2186649 (GB, B) West Germany Patent Application Publication 2634228 (DE, A1) (58 ) investigated the field (Int.Cl. ^7, DB name) F16K 27/00 - 27/12 F16K 5/00 - 5/22 F16L 25/00 F16L 33/00

Claims (8)

(57) [Claims] 1. A resin anticorrosion core 3 having a tubular portion 2 to which an end 1a of a pipe 1 to be connected is externally fitted, and a tubular metallic valve box 4
In the anticorrosion ball valve provided inside, the cylindrical metallic insert member 20 having the female threaded portion 22 with which the male threaded portion 7 of the connected pipe 1 is screwed on the inner peripheral surface is electrically insulated. through the insulating layer 21 having, fixed to the inner peripheral surface 28 of the metallic valve body 4, the ball in close contact with the ball 12 within the metallic valve body 4
The bulging portion 18 that rotatably supports the 12 is formed on the base end of the anticorrosion core 3.
And is closely attached to the bulging portion 18 of the anticorrosion core 3
Insert the inner collar 23 into the end of the insert member 20 inside the valve box 4.
An anti-corrosion ball valve characterized by being provided . 2. A tubular shape to which the end portion 1a of the connected pipe 1 is fitted.
A resin-made anticorrosion core 3 having a portion 2 and a tubular metal valve box 4
In the anticorrosion ball valve provided inside the
The inner peripheral surface has a female screw portion 22 with which the end male screw portion 7 is screwed.
The cylindrical metal insert member 20 has electrical insulation.
Through the insulating layer 21 on the inner surface 28 of the metal valve box 4
And the outer surface 26 of the bulging portion 18 at the base end of the resin anticorrosion core 3 described above.
An end surface 27 of the metal insert member 20, and the metal
The packing 30 is interposed between the inner peripheral surface 28 of the valve box 4 and
Anticorrosion ball valve characterized by . 3. A connected pipe (1) comprises a metallic pipe body (5) and an anticorrosion resin layer (6) covering the inner surface of the pipe body (5),
The anticorrosion ball valve according to claim 1 or 2 , wherein the insert member (20) is made of the same material as the metallic pipe body (5) of the connected pipe (1). 4. The metal valve box 4 has a threaded portion 8 at the end opening.
3. The anticorrosion ball valve according to claim 1, further comprising: a main body 9 having a main body 9; and a nut member 10 that is screwed into the threaded portion 8 of the main body 9 and has an insert member 20 fixed therein in an inserted state. 5. A method according to claim small protrusion 33 is provided on the outer circumferential surface 2a of the tubular portion 2 of the anticorrosive core 3 1 or 2 anticorrosive ball valve according. 6. A seal ring 34 is attached to the tubular portion 2 of the anticorrosion core 3.
The anticorrosion ball valve according to claim 1 or 2, wherein the valve is fitted outside. 7. An insulating layer 21, an insert member 20 and a valve box 4
The anticorrosion ball valve according to claim 1 or 2, which is made of an electrically insulating adhesive that is adhered to the inner peripheral surface 28 of the. 8. The insulating layer 21 is, according to claim 1 or 2 anticorrosive ball valve according made of a rubber layer having an electrical insulating property which is formed by pressurizing硫焼with.