JPH10332003A - Gas control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas control valve wherein maintenance of replacement, repair, etc., can be facilitated in a diaphragm, valve seat, etc. SOLUTION: A gas control valve 10 has a valve seat member 63 holding a valve seat 59 to have a first/second flow path hole 65, 66 passed through over ring in/out of the valve seat 59 from a valve base connection surface 63b, a valve base 16 having a valve seat member connection surface 16a connected thereto and a first/second port flow path 21, 22 opened thereto, inner side sealing gasket 61 interposed between the valve base connection surface 63b and the valve seat member connection surface 16a to communicate the first flow path hole 65 and the first port flow path 21 to seal between the second flow path hole 66 and the second port flow path 22, and an outer side sealing gasket 62 communicating the second flow path hole 66 and the second port flow path 22. The valve base 16 is left as connected to a piping system HH', the valve seat member 63 can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas control valve, and more particularly to a gas control valve for controlling the flow of a gas such as a process gas used in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In recent years, in the semiconductor manufacturing process, as to the processing of wafers such as silicon, the number of cases of performing a single processing for processing one wafer at a time in addition to a single-wafer processing for simultaneously processing several wafers is increasing. ing. Accordingly, it is required to reduce the size of various processing apparatuses, and a small gas control valve for controlling the flow of a process gas such as an etching gas used for processing is also required.

FIG. 5 is a sectional view for explaining the vicinity of a diaphragm valve of a conventional gas control valve 100 disclosed in Japanese Patent Application Laid-Open No. 6-341560. The valve body 1 of the valve 100 includes a valve chamber 2 having a circular cross section and a first chamber.
It has a port 8 and a second port 9. A diaphragm holder 5 that holds a stem 4 that is held vertically movable in the figure is inserted into the valve chamber 2.
The diaphragm holder 5 is pressed downward by a nut member (not shown), and holds the diaphragm 6 between itself and the diaphragm holder 13 of the seat ring 7 fitted on the bottom surface 2a of the valve chamber 2. . Diaphragm 6
Is pressed down by the stem 4 in the figure to come into contact with the valve seat 12, or is lifted up by the gas pressure by lifting the stem 4 upward in the figure to separate from the valve seat 12, As a result, the first port 8 opening to the left in the figure and the valve hole 10
And the second port 9 opened to the right in the figure and the communication hole 11 connected to the second port 9 are blocked or communicated.

In such a valve 100, when it is desired to replace the diaphragm 6, the valve seat 12, and the seat member 7, the valve body 1 provided with the first port 8 and the second port 9 is replaced without removing it from the piping system. can do. That is, the diaphragm 6, the valve seat 12, and the seat ring 7 can be replaced by removing the diaphragm holder 5 and the stem 4.

[0005]

However, in the conventional gas control valve 100 as shown in FIG.
When performing maintenance such as replacement / repair, etc., it is necessary to take them out just above the vicinity of the bottom of the valve chamber 2 in the figure, which is difficult. In particular, as described above, since various processing apparatuses are downsized, other apparatuses are often arranged in the vicinity of the gas control valve 100, and the other apparatuses are obstructive, and replacement or the like is more likely. It is troublesome. In addition, there is a possibility that the inner surface of the valve body 1 (the inner surface of the valve chamber 2) may be damaged, or the corroded metal or the like may be peeled off by touching the surface in contact with the highly corrosive gas, which is a process gas. . Further, when the seat ring 7 is pressed downward by the outer peripheral diaphragm holding portion 13, the seal portion 15 is also pressed against the bottom wall surface 2 a of the valve chamber, thereby sealing between the valve hole 10 and the communication hole 11. However, reliable sealing was difficult, the shape was complicated, and production was troublesome.

An object of the present invention is to solve the above-mentioned problems and to provide a gas control valve capable of easily replacing a diaphragm, a valve seat, and the like. Still another object is to provide a gas control valve that can reliably seal by using a seal member having a simple shape and easy to manufacture.

[0007]

According to a first aspect of the present invention, there is provided a gas control valve in which a valve body and a ring-shaped valve seat are configured to be able to contact and separate from each other. A valve seat member for holding a valve seat, wherein a first flow passage hole penetrating the valve seat member from a valve base connection surface to the inside of the ring of the ring-shaped valve seat and the valve seat member from the valve base connection surface. A valve seat member having a second flow passage hole penetrating outside the ring of the ring-shaped valve seat, a valve seat member connecting surface for connecting to the valve seat member, and a first opening to the valve seat member connecting surface. A valve base having a port flow path and at least one second port flow path, and disposed between the valve base connecting surface of the valve seat member and the valve seat member connecting surface of the valve base in a double ring shape. Seal member, wherein An inner sealing member that communicates the first flow path hole with the first port flow path and seals them between the second flow path hole and the second port flow path; And an outer seal member communicating with the port flow path and sealing between the outside and the outside.

According to the present invention, the valve base having the first and second port flow paths and the valve seat member for holding the valve seat include:
The connecting surfaces of both are sealed by a seal member which is formed separately and arranged in a double ring shape. Therefore, the valve seat member (and the valve body except for the valve base formed thereon) without removing the valve base from the piping system.
Can be removed. Thus, it is not necessary to take out the valve seat or the like from the bottom of the valve chamber which is difficult to take out as in the above-described prior art. The removed valve seat member (or the valve body) is transported to an appropriate place, and is then removed from the valve seat member or the like. The diaphragm, the valve seat and other parts can be removed, and maintenance such as replacement and repair of these parts becomes easy.

In addition, there is less danger of damaging the connection surface of the valve seat of the valve base and each port flow path, and of contacting the process gas contact surface to cause contamination of the process gas.
Also, if the valve seat and the diaphragm are attached (attached) to the valve seat member, the valve seat and the like are also attached by attaching the valve seat member to the valve base. That is, removal and attachment become easy. Furthermore, since it is attached to and detached from the valve seat member connection surface of the valve base, the seal member can be easily removed and attached. Moreover, since the sealing member is a ring-shaped sealing member, the shape is simple and easy to form,
The seal member can be reliably sealed because both the inner seal member and the outer seal member are sandwiched between the valve seat member and the valve base.

It is more preferable that the valve seat member be fastened to the valve base with a bolt through a through hole formed in the valve seat member, since the valve seat member can be removed from the valve base by removing the bolt. In this case, the bolts may be tightened from the surface opposite to the valve base connection surface. The bolts can be tightened and removed regardless of the presence or absence of the gas control valve and other devices arranged adjacently, so that the gas control valve and other devices can be arranged adjacently at a high density, and these devices were used. This is because the size of the device can be reduced.

[0011] To achieve the above object, a second aspect is provided.
The gas control valve according to claim 1, wherein the inner seal member and the outer seal member are arranged in a concentric double ring shape.

According to the present invention, since the inner seal member and the outer seal member are concentric, when a plurality of second port passages are formed in the valve base (for example, from two directions perpendicular to each other) Even when there are two extending second port flow paths), there is no need to change the valve seat member and the inner and outer seal members, so that the valve seat member and the seal member can be shared to accommodate various types of valve bases. .

[0013] In order to further achieve the above object, a third aspect is provided.
The means according to claim 1, wherein the inner seal member and the outer seal member are removed together with the valve seat member when the valve seat member is removed from the valve base. The gist is the gas control valve according to 2.

According to the present invention, when the valve seat member is removed from the valve base, the inner and outer seal members are removed together with the valve seat member, so that the seal member can be removed from the valve seat member connecting surface of the valve base. It becomes unnecessary.
When the seal member is removed, the connection surface of the valve seat member of the valve base and each port flow path are not damaged, and the process gas contact surface does not become a cause of contamination of the process gas.

[0015] In order to further achieve the above object, a fourth aspect is provided.
The ring-shaped resin, wherein at least one of the inner seal member and the outer seal member is partly press-fitted into a seal member recess provided in a ring shape on a valve base connection surface of a valve seat member. The gist of the gas control valve according to claim 3 is:

According to the present invention, since the seal member is partially press-fitted into the seal member concave portion, the valve seat member can be removed and the seal member can be removed. Further, since the seal member is made of resin, the seal member can be easily attached to and detached from the seal member recess, and the seal member can be easily replaced. In addition, since the sealing member is made of resin, the deformability is large and the sealing can be reliably performed. Specifically, a fluorine-based resin, for example, PCTFE (ethylene chloride trifluoride resin), PTFE (ethylene tetrafluoride resin) and the like are mentioned, and these are preferable because of high corrosion resistance.

According to another aspect of the present invention, the above object is achieved.
Means, at least one of the inner seal member and the outer seal member is formed by a ring-shaped pipe having a substantially C-shaped cross section with an opening directed toward an outer peripheral side or an inner peripheral side; A part of the opening is elastically inserted into the provided recess, and the opening is engaged with at least a part of the holding member detachably held by the holding member, whereby the opening is held by the valve seat member. The gist of the present invention is a gas control valve according to a third aspect.

According to the present invention, at least a part of the opening of the C-shaped pipe is engaged and held by the holding member, and the holding member is held by the valve seat member. The seal member can be removed together with the member. In addition, since a part of the holding member is elastically inserted into the concave portion provided in the valve seat member and held detachably, the sealing member together with the holding member can be detached from the valve seat member, and replacement of the sealing member is easy. is there. Further, since the cross-sectional shape of the seal member is substantially C-shaped, the seal can be reliably formed with a large deformability.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. (Example 1) FIG. 1 is a longitudinal sectional view of a pilot type gas control valve according to an embodiment of the present invention. Gas control valve 1
0 is the gas control valve body 10a and the valve base 1
Consists of six. The gas control valve body 10a includes a valve seat member 63, an intermediate member 57, a pilot valve cylinder 51, and the like. On the other hand, the valve base 16 has a first port 21 opening to the right in the figure and a second port 2 opening to the left in the drawing.
2, the first port vertical flow channel portion 21a and the second port vertical flow channel portion 22a are opened in the valve base upper surface (valve seat member connection surface) 16a.

The valve seat connection surface 1 of the valve base 16
6a and the valve base connection surface 63b of the valve seat member 63 are connected. In this example, the valve seat member 63 is fastened to the valve base 16 by a bolt 64 inserted through a through hole (not shown) penetrating the valve seat member vertically in the drawing.
A first flow passage hole 65 formed substantially at the center of the valve seat member 63
And the second flow path holes 66 formed beside the first port vertical flow path portion 21a and the second flow path
It communicates with the port vertical flow path 22a. A ring-shaped inner sealing gasket 61 and an outer sealing gasket 62 arranged concentrically between the valve base 16 and the valve seat member 63 are provided with a first port flow path 21 and a first flow path hole 65, In addition, the second port flow path 22 and the second flow path hole 66 communicate with each other, and the seal between both ports and the outside is maintained.

On the upper surface of the valve seat member 63, there is formed a projection 63a having a substantially bottomed cylindrical shape.
A first flow path hole 65 and a second flow path hole 66 are opened at the bottom inside. A ring-shaped valve seat 59 is provided at the bottom of the protrusion 63a.
The first flow path hole 65 is opened in the ring of the valve seat 59, and the second flow path hole 66 is opened outside the ring. It is trying to block.

Above the valve seat 59, the diaphragm 5
The valve body 58 is held so as to be able to abut or separate from the valve seat 59 via 4 to form a poppet valve type diaphragm valve body. Further, a diaphragm fixing bracket 56 pressed downward in the figure by an intermediate member 57 screwed into a female screw formed on the inner periphery of the protruding portion 63a, and a valve seat member 6
3, the outer periphery of the diaphragm 54 is fixed. This prevents the gas flowing between the first and second flow path holes from leaking upward.

A through hole 57 formed in the center of the intermediate member 57
A piston rod 53 is inserted into and held in a in a vertically slidable manner. A piston 52 is attached to the piston rod 53, and both are integrated.

Above the intermediate member 57, a pilot valve cylinder 51 is screwed and fixed to the intermediate member 57.
Inside the pilot valve cylinder 51, a piston 52 and a return spring 55 for urging the piston rod 53 and the valve body 58 downward (to close the valve) via the piston 52 are attached. A driving air port 60 is formed along the central axis of the pilot valve cylinder 51 and opens to the upper surface in the figure. A rod center hole 53c is formed in the center axis of the piston rod 53 at a depth reaching below the rod bulging portion 53a from the upper end of the piston rod 53 in the drawing, and further, directly below the rod bulging portion 53a. Is a communication hole 53 that penetrates the piston rod 53 in the radial direction (left-right direction in the figure) and crosses the rod center hole 53c.
d is formed. As a result, the space V formed by the upper surface of the intermediate member 57 and the lower surface of the piston 52 becomes a communication hole 53d,
It is configured to communicate with the driving air port 60 through the rod center hole 53c.

The gas control valve 10 constructed as described above
When the compressed air is not sent from the drive air port 60, the valve is closed. That is, since the piston 52 and the piston rod 53 are urged downward (the valve closing direction) by the return spring 55, the piston rod 53 pushes the valve body 58 downward in the drawing, and the first or second port is opened. The valve element 58 is brought into contact with the valve seat 59 via the diaphragm 54 against the gas pressure of the process gas or the like. Therefore, the first
The port flow path 21 and the second port flow path 22 are shut off (sealed).

Next, when compressed air is sent from the driving air port 60 into the space V defined by the upper surface of the intermediate member 57 and the lower surface of the piston 52 through the rod center hole 53c and the communication hole 53d, the piston 52 and the piston 52 The rod 53 moves upward. Then, the diaphragm 54 and the valve body 58 are moved upward by the gas pressure of the process gas, the purge gas, or the like, and the valve is opened, so that the first port flow path 21 and the second port flow path 22 communicate with each other so that the first port flow path 21 and the second port flow path 22 communicate with each other. The gas circulates. By controlling the compressed air sent to the drive air port 60 in this manner, the diaphragm valve (diaphragm 54, valve 58) is opened and closed, and the gap between the first port flow path 21 and the second port flow path 22 is opened. Can be controlled.

After such a gas control valve 10 is attached to the piping system HH 'shown by a broken line in the figure, for example, it is assumed that a case where it is desired to replace the valve seat 59 occurs. In this case, by removing the bolt 64 that fastens the valve seat member 63 to the valve base 16, the valve seat member 63 and the intermediate member 57 located above the valve seat member 63 from the valve seat member connecting surface 16 a are removed. Remove the pilot valve cylinder 51 and the like. That is, the gas control valve 10 (gas control valve main body 10a) other than the valve base 16 is removed from the piping system HH '. Then, the removed gas control valve body 1
Oa is further decomposed at an appropriate place. That is, after removing the intermediate member 57 from the valve seat member 63 and taking out the valve body 58, the diaphragm fixing bracket 56, and the diaphragm 54, the valve seat 59 is taken out from the upper surface 63a side of the valve seat member 63 and replaced. By doing so, the valve seat member 63 and the like can be removed from the valve base 16 simply by loosening and removing the bolt 64 from above in the figure, so that even if other equipment is nearby, it can be easily removed.

Further, the inner sealing gasket 61 and the outer sealing gasket 62, which are ring-shaped sealing members, remain on the valve seat member connecting surface 16a, but are substantially planar, unlike the above-mentioned prior art. These gaskets 61 and 62 are located on the valve seat member connecting surface 16a.
Can also be easily removed. Further, since the inner seal gasket 61 and the outer seal gasket 62 have a simple ring shape, their manufacture is easy. In addition,
In this example, the inner seal gasket 61 is made of PCTFE.
A stainless steel ring was used for the outer seal gasket 62. By using two gaskets 61 and 62 having different deformability, that is, using a resin having a high deformability for one of them (in this example, the inner sealing gasket 61), a dimensional error of the gasket or the like is absorbed. This is to ensure that even a gasket can be sealed.

Next, after replacing the valve seat 59, the valve seat member 6 is replaced.
3, the gas control valve body 10a is assembled by assembling the diaphragm 54, the valve body 58, the diaphragm fixing bracket 56, the intermediate member 57, and the like. When necessary, the inner seal gasket 61 and the outer seal gasket 62 are replaced with new ones and mounted on the valve seat member connection surface 16a. Thereafter, the valve seat member 63 (gas control valve body 1)
0a) was set such that the valve base connection surface 63b and the valve seat member connection surface 16a faced each other via the gaskets 61 and 62, and the bolt 64 was tightened to replace the valve seat 59 of the gas control valve 10. It will be.

Therefore, since the valve seat member 63 (gas control valve body 10a) can be removed without removing the valve base 16, the removal operation can be easily performed even in a narrow place. Further, since the valve seat 59 and the like can be replaced and repaired at another place, the valve seat 59 and the like can be easily removed, and the risk of damaging the first flow passage hole 65 and the like can be reduced. Further, gaskets 61 and 6 for inner and outer seals are provided.
Desorption of 2 is also easy. Further, it is easy to connect the valve seat member 63 to the valve base 16. It should be noted that another gas flow path may be provided on the valve base 16 so that a plurality of gas control valve bodies 10a and other devices can be attached, so as to have a so-called manifold function.

(Embodiment 2) In this embodiment, as shown in FIG. 2, two second port passages (22, 2
2 ′) is formed, and there is no difference from the above-described gas control valve 10 of the first embodiment except for the valve base 16, and a description of similar parts will be omitted. In this example, the two second port flow paths 22, 22 'are formed at right angles to each other (rightward and upward in the figure), and the second port vertical flow paths 22a, 22a' Openings are provided between the inner sealing gasket 61 and the outer sealing gasket 62 which are arranged concentrically. Thus, for example, the process gas flowing from the first port flow path 21 can be controlled by the gas control valve 10 to flow out and shut off to the second port flow path 22, and can be discharged from another second port flow path 22 '. An inert gas (purge gas) can be made to flow through the second port flow path 22.

Thus, the two gaskets 61, 62
Are arranged in a concentric double ring shape, it is not necessary to change the shapes of the gaskets 61 and 62 and the valve seat member 63 even if a plurality of second port channels 22 are opened between them.
Therefore, the gaskets 61 and 62 and the valve seat member 63 (or the gas control valve main body 10a) can be made common, so that various types of valve bases 16 can be supported. In addition, in order to increase the number of types of the valve base 16, in addition to the case where the number and the position of the second port flow path are different, the case where the shape of the joint of each port is different such as a metal gasket joint or a double bite joint. and so on. In FIG. 2, at each corner,
A screw hole 16b for fastening with the bolt 64 is formed.

(Embodiment 3) The present embodiment shown in FIG.
Is a gas control valve 10 ′ similar to that of FIG.
With the attachment and detachment of the (gas control valve body 10b), the inner seal gasket 61 'and the outer seal gasket 6'
2 'is different in that it can be attached and detached, and the others are the same. Therefore, the same parts are denoted by the same reference numerals, and the description of the same parts will be omitted.

In this embodiment, the first passage hole 65 of the valve seat member 63 is provided.
Immediately below the gasket, a gasket recess 63d formed coaxially with the first passage hole 65 and slightly larger in diameter than the first passage hole is formed. An inner sealing gasket 61 'made of PCTFE resin is press-fitted into the gasket recess 63d, and is detachably integrated with the valve seat member 63. Also, the gasket recess 6
3d is formed such that the upper side surface is concavely formed in a ring shape and engages with the upper side surface portion of the inner sealing gasket 61 'which is formed so as to be slightly bulged, thereby making it difficult for the gasket 61' to come off. ing. In addition, in this example, the case where the gasket concave portion 63d is formed in a substantially cylindrical shape is shown, but the gasket concave portion 63d is not limited to this, and may be configured with, for example, a ring-shaped groove. Further, a similar structure may be employed for the outer seal gasket.

On the other hand, the outer sealing gasket 62 ′
As shown in FIG. 4 (a), this is a ring-shaped gasket made of stainless steel having a substantially C-shaped cross section in which an opening P is formed on the outer peripheral side. Such a gasket having a substantially C-shaped cross section has a large deformability and can reliably seal. The gasket 62 'is engaged with the retainer 70 by integrally inserting the central opening edge 70a of the gasket retainer 70 shown in the plan view and the sectional view in FIGS. 4B and 4C into the opening P thereof. (See FIG. 4D). This gasket Retinaa 70,
4 (b) is a substantially square stainless steel plate, and the center of the left and right sides in FIG. 4 (b) is substantially U in the thickness direction.
The spring portion 70b is bent in a letter shape. An insertion hole 70c for inserting the bolt 64 is formed at each corner.

The spring part 7 of this gasket retainer 70
0b is inserted into the retainer holding recess 63c formed on the valve base connection surface 63b of the valve seat member 63,
The gasket retainer 70 and the outer seal gasket 6 are elastically engaged with the spring portion 70b.
2 ′ is detachably held by the valve seat member 63. Note that a similar structure may be employed for the inner seal gasket.

In this manner, the inner seal gasket 6
1 'and the outer sealing gasket 62'
3, when the valve seat member 63 (gas control valve body 10b) is removed from the valve base 16, the gaskets 61 'and 62' together with the valve seat member 63.
Also, the gasket does not need to be removed from the valve seat member connection surface 16a as in the first embodiment described above.
Maintenance such as replacement and repair of the valve seat 59 and the like becomes easier. Further, since the outer seal gasket 62 'can be replaced by attaching and detaching the gasket retainer 70, the replacement operation can be more easily performed.

In the above embodiment, an example was shown in which a resin such as PCTFE was used for the inner seal gaskets 61 and 61 ', and a metal such as stainless steel was used for the outer seal gaskets 62 and 62'. Good. The present invention is not limited to the above embodiment, and can be appropriately modified and applied without departing from the spirit of the invention.

[0039]

As described in detail above, according to the first aspect of the present invention, the valve seat member and the gas control valve body can be removed without removing the valve base from the piping system, and the parts can be repaired. And maintenance such as replacement becomes easy. Further, the sealing member can be easily removed and attached. According to the second aspect of the present invention, even when a valve base having a plurality of second port passages formed therein is used, the valve seat member and the sealing member are shared to provide various types of valve bases. Can respond to.

Further, according to the third aspect of the present invention,
When the valve seat member is removed, both the inner and outer seal members can be removed. Further, according to the invention described in claim 4, the valve seat member can be removed and the seal member can be removed. Further, since the seal member is made of resin, the seal member can be easily attached to and detached from the concave portion for the seal member, and the seal member can be easily replaced. According to the fifth aspect of the invention, when the valve seat member is removed, the seal member can be removed together with the holding member.
The seal member together with the holding member can be attached to and detached from the valve seat member, and replacement of the seal member is easy. Furthermore, the seal member having a substantially C-shaped cross section has a large deformability and can reliably seal.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pilot type gas control valve according to a first embodiment.

FIG. 2 is a plan view of a valve base according to a second embodiment.

FIG. 3 is a vertical sectional view of a pilot type gas control valve according to a third embodiment.

4 (a) is a cross-sectional view of an outer seal gasket 62 ′, (b) is a plan view of a gasket retainer 70, (c) is a cross-sectional view of a gasket retainer 70, and (d) is a gasket and a retainer used in the third embodiment. It is sectional drawing of the assembly state of.

FIG. 5 is a longitudinal sectional view of a conventional gas control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Gas control valve 10a, 10b Gas control valve main body 16 Valve base 16a Valve seat member connection surface 21 First port flow path 22 Second port flow path 21a First port vertical flow path part 22a Second port vertical flow path part 51 Pilot Valve cylinder 52 Piston 53 Piston rod 54 Diaphragm 55 Return spring 56 Diaphragm fixing bracket 57 Intermediate member 58 Valve element 59 Valve seat 60 Port for driving air 61, 61 'Gasket for inner seal 62, 62' Gasket for outer seal 63 Valve seat member 63b Valve base connection surface 63c Retainer holding recess 63d Gasket recess 65 First flow passage hole 66 Second flow passage hole 70 Gasket retainer H, H 'Piping system

Claims (5)

[Claims] 1. A gas control valve in which a valve body and a ring-shaped valve seat are configured to be able to contact and separate from each other, wherein the valve seat member holds the ring-shaped valve seat, and the valve seat member is a valve base. A valve having a first flow passage hole penetrating from the connection surface to the inside of the ring of the ring-shaped valve seat, and a second flow passage hole penetrating the valve seat member from the valve base connection surface to the outside of the ring of the ring-shaped valve seat. A seat member, a valve base having a valve seat member connection surface for connecting to the valve seat member, a first port flow path and at least one second port flow path opening to the valve seat member connection surface, A seal member interposed between a valve base connecting surface of a valve seat member and a valve seat member connecting surface of the valve base and arranged in a double ring shape, wherein the first flow passage hole and the first port flow And the second flow path hole And the second
An inner seal member that seals between the port flow path and an outer seal member that communicates the second flow path hole with the second port flow path and seals between the outside and the outside. Gas control valve. 2. The gas control valve according to claim 1, wherein the inner seal member and the outer seal member are arranged in a concentric double ring shape. 3. The valve according to claim 1, wherein when the valve seat member is removed from the valve base, the inner seal member and the outer seal member are also removed together with the valve seat member. A gas control valve according to claim 1. 4. At least one of the inner seal member and the outer seal member is a ring-shaped resin partly press-fitted into a seal-shaped concave portion provided in a ring shape on a valve base connecting surface of a valve seat member. The gas control valve according to claim 3, wherein: 5. At least one of the inner seal member and the outer seal member is formed by a ring-shaped pipe having a substantially C-shaped cross section with an opening directed toward an outer peripheral side or an inner peripheral side, and is provided on the valve seat member. The at least one opening is engaged with at least a part of the opening by a holding member which is elastically inserted into the recessed portion and held detachably, and is held by the valve seat member. Item 4. A gas control valve according to Item 3.