KR20100107398A - Valve for high-pressure gas vessel and high-pressure gas vessel - Google Patents

Abstract

PURPOSE: A high-pressure gas container and a valve therefor are provided to improve safety by preventing a gas leak and to reduce manufacturing costs. CONSTITUTION: A valve for a high-pressure gas container comprises a valve body(3), a valve stem(5) for changing an opening degree, and a valve seat(6). The valve body is attached on a high-pressure gas container. The valve stem is formed inside the valve body. The valve seat accepts the valve stem. Sealing members(5b) are formed in the valve body and the valve stem and close a gas passage.

Description

VALVE FOR HIGH-PRESSURE GAS VESSEL AND HIGH-PRESSURE GAS VESSEL}

The present invention relates to a valve attached to a high pressure gas container and a high pressure gas container with the valve.

For example, in order to supply the gas used in a semiconductor manufacturing process, the high pressure gas container with a valve is used. Since such gases have a lot of highly toxic gases that damage the human body or the equipment, it is necessary to prevent a small leak, to ensure safety and to not affect the environment. Therefore, the valve for a high pressure gas container is provided with the valve body attached to a high pressure gas container, the valve body for changing the opening degree of the gas flow path formed in this valve body, and the valve seat for accommodating this valve body, At least one of the valve body and the valve seat has a sealing member made of synthetic resin, and the valve body is pressed against the valve seat through the sealing member, so that the gas flow path is closed. Since the synthetic resin sealing member has deformability, even if minute foreign matters are mixed in the gas flow path or minute scratches or the like can be prevented, gas leakage can be prevented.

As the synthetic resin constituting such a sealing member, polychlorotrifluoroethylene (PCTFE) resin is generally used. PCTFE resin is considered to be excellent in durability and corrosion resistance because it is excellent in hardness aptitude and workability and does not cause swelling or strength drop for many gas species.

However, it is pointed out that PCTFE resins have problems in corrosion resistance and durability depending on the gas species, and the sealing performance is deteriorated due to a decrease in physical strength or swelling. Then, what makes a sealing member the polyvinylidene fluoride (PVDF) agent or ethylene tetrafluoride (PTFE) agent is proposed (refer patent document 1, patent document 2).

Patent Document 1: Japanese Unexamined Patent Publication No. 5-223176

Patent Document 2: Japanese Unexamined Patent Publication No. 2005-157913

Since the PVDF resin of patent document 1 has a continuous use temperature of 150 degreeC, there exists a problem that it softens when the inside of a high pressure container is heated and dried after washing | cleaning, and also polar solvents and amines, such as a ketone and an ether, There is also a problem of softening or dissolving.

Since the PTFE resin of patent document 2 is difficult to flow even when heated, it cannot perform injection molding or extrusion molding, and since the thermal deformation at the time of shaping | molding small components like a sealing member is large, a special function is needed for processing, It is not suitable for mass production, and there exists a problem that manufacturing cost increases.

In recent years, when the PCTFE resin is used as a sealing member of a valve for an ammonia gas container, it has been found that cracks and peeling are seen on the sealing member when used for a long time, and it is understood that improvement is needed to increase safety. Could.

An object of the present invention is to provide a valve for a high pressure gas container and a high pressure gas container that can solve the above problems.

A valve for a high pressure gas container to which the present invention is applied includes a valve body attached to a high pressure gas container, a valve body for changing the opening degree of a gas flow path formed in the valve body, and a valve seat for accommodating the valve body. At least one of the valve body and the valve seat has a sealing member made of a synthetic resin, and the gas flow path is closed by pressing the valve body through the sealing member.

The high pressure gas container valve of the present invention is characterized in that at least one of polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) resin and polyether sulfone (PES) resin is used as the synthetic resin.

Especially, PEEK resin and PES resin are preferable and it is more preferable to use PEEK resin.

In a valve using a conventional PCTFE resin sealing member, the flexibility of the PCTFE resin is lowered, and cracking or breaking occurs in the sealing member due to the action of high pressure, and the sealing performance is lost. One. Thus, the inventors of the present invention have diligently studied, and have found that the present invention exhibits excellent sealing performance by using at least one of PEEK resin, PPS resin and PES resin as the material of the sealing member. In addition, PEEK resin, PPS resin, and PES resin have a higher continuous use temperature than PVDF resin, and do not soften when the inside of the high-pressure container is heated and dried after washing, and also softened by a polar solvent or amine such as ketone or ether. It does not dissolve and, moreover, it is more easily flowable by heating than PTFE resin, so that injection molding and extrusion molding can be performed, which is suitable for mass production.

The high pressure gas container of this invention is equipped with the high pressure gas container valve of this invention. According to the high pressure gas container of the present invention, no cracking or breaking occurs in the sealing member even when the high pressure is applied, and the sealing performance can be maintained to prevent the leakage of gas.

The inventors of the present invention have found that by using at least one of PEEK resin, PPS resin and PES resin as the material of the sealing member, excellent corrosion resistance against ammonia is exhibited and durability is excellent due to a small decrease in flexibility. Therefore, in the high pressure gas container of the present invention, it is particularly preferable that the liquefied ammonia gas is filled as the high pressure gas. Thereby, the leakage of the gas from the high pressure gas container filled with ammonia gas can be prevented.

The high-pressure gas filled in the high-pressure gas container of the present invention is, for example, a compressed gas having a pressure (a gauge pressure, which is the same below) of 1 to 15 megapascals at a commercial temperature. Compressed gas of 15 megapascals or pressure of 1 to 15 megapascals at a temperature of 35 ° C. or liquefied gas of 1 to 15 megapascals of pressure at a commercial temperature. Or a liquefied gas having a temperature of 35 ° C. or lower when the pressure is 1 to 15 megapascals.

According to the present invention, a valve for a high pressure gas container which is excellent in durability and corrosion resistance, improves safety by preventing gas leakage, reduces environmental impact, reduces manufacturing costs, and contributes to the production or consumption of high pressure gas. And a high pressure gas container.

1 is a cross-sectional view of a valve for a high pressure gas container according to an embodiment of the present invention.
2 is a plan view of a sealing member according to an embodiment of the present invention.

The valve 2 attached to the high pressure gas container 1 shown in FIG. 1 includes a valve body 3 attached to the high pressure gas container 1, a gas flow path 4 formed on the valve body 3, and a gas flow path. The valve body 5 for opening degree change of (4), the valve seat 6 for accommodating this valve body 5, and the operation mechanism 7 are provided.

Although the container 1 is filled with liquefied ammonia gas as high pressure gas in this embodiment, it is not limited to this. Although the material of the container 1 is stainless steel in this embodiment, it is not specifically limited. In addition to the stainless steel, it is preferable to polish the inner surface of the container 1 using, for example, tempered manganese steel, aluminum, chromium-molybdenum steel, etc., which is excellent in rust prevention property, to prevent generation of fine foreign matter.

In the present embodiment, the valve body 3 is made of stainless steel and attached to the high pressure gas container 1 through the male screw portion 3a, and attached to the gas supply pipe (not shown) via the male screw 3b.

The gas flow passage 4 includes a first flow passage 4a, a second flow passage 4b, and a valve body storage chamber 4c. One end of the first flow passage 4a serves as a gas inlet 4d which leads to the inside of the high pressure gas container 1, the other end is connected to the valve body storage chamber 4c, and the middle part is connected to the relief valve 8. do. One end of the second flow passage 4b is a gas discharge port 4e leading to the gas supply pipe, and the other end is led to the valve body storage chamber 4c. The gas discharge port 4e is closed by the cover 9 which is screwed to the connection screw portion 3b until the valve body 3 is connected to the gas supply pipe.

The valve body 5 has a cylindrical valve rod 5a and a sealing member 5b attached to the valve rod 5a, and the valve body storage chamber is formed from the recess 3c formed in the valve body 3. Is inserted into (4c). The valve rod 5a is made of stainless steel, for example. As shown in Fig. 2, the sealing member has a ring shape and fits into an annular groove formed at one end of the valve rod 5a.

The valve seat 6 is comprised by the annular area | region which surrounds the connection port of the 1st flow path 4a in the valve main body 3, and the valve body storage chamber 4c.

The operation mechanism 7 includes a diaphragm 7a for closing the valve body storage chamber 4c and the recessed portion 3c in an airtight state, a spring 7b for pressing the valve body 5 against the diaphragm 7a, Rod 7c receiving elasticity of spring 7b through diaphragm 7a and spacer, handle 7d attached to rod 7c, and support cylinder 7e attached to valve body 3 via a screw member. The rod 7c is screwed to the support cylinder 7e.

By rotating the handle 7d in one direction, a rod 7c which is screwed to the support cylinder 7e presses the valve body 5 toward the valve seat 6, and the sealing member 5b moves the valve seat 6. ), The gas flow passage 4 is closed. By rotating the handle 7d in the other direction, the pressure toward the valve seat 6 of the valve body 5 by the rod 7c is released, and with the valve body 5 by the elasticity of the spring 7b. The gas passage 4 is opened by the sealing member 5b displaced away from the valve seat 6. In addition, rotation of the handle 7d in the other direction is regulated by contact of the rod 7c with the stopper portion formed in the support cylinder 7e at a predetermined position where the gas flow passage 4 is fully opened.

The sealing member 5b is made of a synthetic resin, and any one of PEEK resin, PPS resin and PES resin is used as the synthetic resin, and commercially available as an engineering plastic can be used. In addition, the material of the sealing member 5b may be resin which mixed two or all of PEEK resin, PPS resin, and PES resin. Alternatively, a plurality of ring-shaped sealing members 5b may be disposed, and concentrically arranged with different radial dimensions, and may be arbitrarily selected from PEEK resin, PPS resin, and PES resin as the respective materials. In short, as the material of the sealing member 5b, one or more of PEEK resin, PPS resin and PES resin may be used. In addition, the shape of a sealing member is not limited, For example, you may make a disk-shaped sealing member adhere to a valve body.

Example

The following test is done as Example 1, Example 2, and the comparative example 1 using the valve 2 of the said embodiment, and the result is shown in the following Table 1.

(Example 1)

The sealing member 5b made of four PEEK resins (PK-450 made by Japan Polyphenco) was immersed in liquefied ammonia for 90 days, and the total length of the sealing member 5b before and after the test (following the moving direction of the valve body 5). Dimension], the mass and the surface hardness by the "Asuka-rubber hardness meter type D durometer" manufactured by Polymer Weigher Co., Ltd. were measured, and the change in appearance was also observed.

(Example 2)

The same test as in Example 1 was carried out except that the sealing member 5b was made of PPS resin (TPS-PPS (NS) -SC manufactured by Toyo Plastic Hole).

(Comparative Example 1)

The same test as in Example 1 was conducted except that the sealing member 5b was made of PCTFE resin.

From Table 1, although the sealing member 5b had little swelling and the total length change rate and the mass change rate were small in both an Example and a comparative example, the hardness change after immersion in liquefied ammonia was not confirmed in Example 1 and Example 2, In contrast, in Comparative Example 1 it was confirmed. In addition, discoloration was not confirmed in Example 1 and Example 2, but brown discoloration was confirmed in Comparative Example 1. As a result of performing X-ray photoelectron spectroscopy (XPS analysis) on the surface of the resin of Comparative Example 1, which turned brown, deterioration of the surface of the resin occurred due to detachment, nitriding and oxidation of chlorine (C1). Thereby, it can be confirmed that the sealing member 5b of the embodiment maintains the properties of the resin and has corrosion resistance against ammonia.

Moreover, the same test was done also about the sealing member 5b made from PES resin (4100G made from Yasojimaproside), and it confirmed that it had corrosion resistance with respect to ammonia.

The following test is performed as Example 3, Example 4, Example 5, and the comparative example 2 using the valve 2 of the said embodiment, and the result is shown in the following Table 2.

(Example 3)

The same PEEK resin sealing member 5b as used in Example 1 was attached to the valve body 5, the handle 7d was reciprocally rotated in a non-pressurized state, and the gas flow path 4 was rotated in one cycle / minute. The test which opens and closes 5000 times is performed, and the handle required for closing the entire length of the sealing member 5b (dimensions along the moving direction of the valve body 5) and the gas flow passage 4 from the fully open state before and after the test ( The rotation angle of 7d) was measured. In addition, at the time of closing of the gas flow path 4, in order to press the sealing member 5b to the valve seat 6 with a constant force, the torque made to act on the handle 7d was 12 N * m.

Moreover, in order to confirm the airtight state of the gas flow path 4 of the closed state, the method of using a foamable gas leak detection liquid, and the high pressure gas container decompressed in a vacuum state are put in the helium gas atmosphere, and the helium which penetrated in the container is detected. The method was performed.

(Example 4)

The same test as in Example 3 was conducted except that the sealing member 5b was made of PPS resin.

(Example 5)

The same test as in Example 3 was conducted except that the sealing member 5b was made of PES resin.

(Comparative Example 2)

The same test as in Example 3 was conducted except that the sealing member 5b was made of PCTFE resin.

From Table 2, although the total length change of the sealing member 5b did not show a big difference in an Example and a comparative example, the change of the rotation angle of the handle 7d which is necessary for closing the gas flow path 4 from a fully open state, In Examples 3 to 5, while it is 34 ° to 47 °, in Comparative Example 2, it can be seen that it is increased to 60 °. This shows that in Examples 3 to 5, the deformation when the constant torque is applied to the handle 7d is smaller than that of Comparative Example 2.

Moreover, it was confirmed that the sealing member 5b made of PEEK resin, PPS resin and PES resin was not damaged and there was no leakage of He gas. On the other hand, the sealing member 5b made of PCTFE resin had no leakage of He gas. Minor damage was identified. Accordingly, it can be confirmed that the sealing member 5b of the embodiment has sufficient mechanical strength and excellent durability even when the gas flow passage 4 is closed by applying a large torque.

In Example 6, Example 7, and Comparative Example 3, the following tests are performed using the valve 2 of the said embodiment, and the result is shown in the following Table 3.

(Example 6)

As the sealing member 5b, the same test as in Example 3 was conducted except that a PEEK resin agent immersed in liquefied ammonia for 90 days was used.

(Example 7)

As the sealing member 5b, the test similar to Example 3 was performed except having used the PPS resin agent immersed in liquefied ammonia for 90 days.

(Comparative Example 3)

As the sealing member 5b, the same test as in Example 3 was conducted except that the PCTFE resin made by immersing in liquefied ammonia for 90 days was used.

From Table 3, while in Example 6 and Example 7, there was no gas leakage, in Comparative Example 3, it was confirmed that gas leakage occurred after the test. In addition, from the comparison of the variation amounts of Examples 3 and 4 with the variation amounts of Examples 6 and 7, and the comparison of the variation amounts of Comparative Example 2 and Comparative Example 3, the sealing member 5b of the example had a decrease in flexibility against ammonia. It can be confirmed that it exhibits small corrosion resistance.

The present invention is not limited to the above embodiments and examples. For example, by attaching a ring-shaped sealing member to the valve seat, the valve seat may have a sealing member instead of the valve body. Alternatively, both the valve body and the valve seat may have a sealing member. In this case, the sealing member of the valve body may be pressed against the valve seat when the gas flow path is closed, and the sealing member of the valve seat may be pressed against the valve body. The sealing members may be pressed against each other. In addition, the kind of valve is not limited to a manual switching valve, For example, it may be a thing provided with the function as a pressure reducing valve, or an electric valve.

1: high pressure gas container 2: valve
3: valve body 4: gas flow path
5 valve body 5b sealing member
6: valve seat

Claims (3)

A valve body attached to the high pressure gas container, a valve body for changing the opening degree of the gas flow path formed in the valve body, and a valve seat for accommodating the valve body, wherein at least one of the valve body and the valve seat A valve for a high pressure gas container having a synthetic resin sealing member, wherein the gas flow path is closed by pressing the valve body through the sealing member to the valve seat.
As the synthetic resin, at least one of a polyether ether ketone resin, a polyphenylene sulfide resin and a polyether sulfone resin is used. The high pressure gas container of Claim 1 with which the valve for high pressure gas container is attached. The high pressure gas container according to claim 2, wherein liquefied ammonia gas is filled as the high pressure gas.

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