JP2000346295A - Connecting mechanism between gas cylinder and gas pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect surely and easily gas leak from a connection part between a gas cylinder and a gas pipe. SOLUTION: This connecting mechanism 40, which is a mechanism connecting a gas pipe 26 to a gas outlet nozzle 16 of a particular high pressure gas cylinder 10, comprises a nitrogen gas flow path 42 as a supply means of nitrogen gas and a pressure detection means, distribution ring 44 distributing nitrogen gas to the nitrogen gas flow path 42, nitrogen gas pipe 46 supplying nitrogen gas to the distribution ring 44, and a pressure gage 48 measuring a nitrogen gas pressure in the nitrogen gas pipe to output a pressure measured value. The nitrogen gas flow path 42 is four flow paths arranged with a 90 deg. space in a peripheral direction of a gap pipe to be inserted in a lengthwise direction in a pipe wall. A collar washer has a protruded part having an opening communicating with the gas pipe 26 in the center, inner side annular surface between the protruded part and an annular groove, and an outer side annular surface extended outward from the annular groove to be made lower than the inner side annular surface by a height difference (H) of 0.05 mm, the inner side annular surface functions as a packing touch surface. A gas outlet of the nitrogen gas flow path 42 is provided in the annular groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection mechanism between a gas cylinder and a gas pipe, and more particularly, to a connection mechanism between a gas cylinder and a gas pipe provided with a structure capable of easily detecting a gas leak.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing factory, semiconductor devices are manufactured by performing processing using various gases. For example, in the film forming process, a semiconductor layer is formed on a substrate using a considerably dangerous gas such as arsine, phosphine, and silane, and in the dry etching process, a dangerous gas such as chlorine gas is used as an etching gas. Etching. In the ion implantation process, a gas containing arsenic may be used. Such a gas is usually stored under high pressure in a special high-pressure gas cylinder integrated in a factory gas storage, and if necessary, depressurized through a factory gas supply system and supplied to required locations. . The special high-pressure gas cylinder is usually connected to a gas pipe of a gas supply system via a connection mechanism having a special base.

[0005] Here, with reference to FIGS. 5 to 8, a description will be given of a configuration of a connection mechanism for connecting a gas outlet of a special high-pressure gas cylinder and a gas pipe via a base. FIG. 5 is a perspective view showing a configuration of a connection mechanism in which a gas pipe is connected to a gas outlet of a special high-pressure gas cylinder via a base, FIG. 6 is an exploded view of the base, FIG. 7 is a longitudinal partial cross-sectional view of a collar washer, and FIG. 8 shows FIG.
1 is a front view of a color washer taken along the line II of FIG. As shown in FIG. 5, the conventional connection mechanism 1 for connecting the special high-pressure gas cylinder 10 and the gas pipe 26 is a simple mechanism including only a base including an assembly of connection parts such as a base nut 30.

As shown in FIG. 5, a special high-pressure gas cylinder 10 has a gas outlet 1 provided with an on-off valve (cylinder main stopper) 12.
4 is provided at the upper part, and the gas flows out through the gas outlet 14. When the on-off valve 12 is tightened downward, the gas outlet 14 is closed, and when the on-off valve 12 is loosened upward, the gas outlet 14 is opened. The gas outlet 14 is provided with the on-off valve 12.
A gas outlet nozzle 16 is provided in a direction orthogonal to the operation direction of the above, from which gas flows out. Gas outlet nozzle 16
As shown in FIG. 6, the thread 18 extends along the outer wall of the nozzle.
And has a packing contact surface 20 on the tip end surface, and is connected to a gas pipe 26 via an annular packing (gasket) 22 and a base 24 to prevent gas leakage.

The base 24 is joined to the end of the gas pipe 26 and has a collar washer 28 in surface contact with the packing contact surface 20 via the packing 22, and a thread groove (corresponding to the thread 18 of the gas outlet nozzle 16). (Not shown) on the inner wall, and slides freely along the gas pipe 26 to cover the collar washer 24 and is configured as a set of a base nut 30 screwed to the gas outlet nozzle 16. . As shown in FIGS. 7 and 8, the collar washer 28 has an opening 29 communicating with the gas pipe 26, and a projection 32 penetrating through the central hole of the packing 22 and penetrating into the gas outlet nozzle 16. The annular surface at the end surrounding the protrusion 32 in an annular shape is a packing contact surface 34, and the packing contact surface 34 has an annular groove 36.

The gas outlet 14 of the special high-pressure gas cylinder 10
When connecting the gas pipe 26 to the
The packing 22 is placed on the packing contact surface 20 of the gas outlet nozzle 16, and the packing contact surface 34 is brought into surface contact with the packing 22 while the protrusion 32 of the collar washer 28 penetrates the center hole of the packing 22, and the cap nut 30 is connected to the gas. Piping 2
6 and tighten it into the gas outlet nozzle 16
4 is attached. By tightening the cap nut 30,
The gasket contact surface 20 of the gas outlet nozzle 16 and the gasket contact surface 34 of the collar washer 28 are in close contact with each other through the gasket 22 while maintaining gas tightness.

As can be seen from the above description, the action of the packing 22 is important for the gas-tight connection between the gas outlet 14 of the special high-pressure gas cylinder 10 and the gas pipe 26. A new packing that has not deteriorated must be installed correctly. Therefore, in the manufacturing plant, the packing is replaced every time a special high-pressure gas cylinder whose gas pressure is reduced due to the use of gas is replaced with a special high-pressure gas cylinder having a sufficient gas pressure.

[0008]

By the way, the worker has
Although the special high-pressure gas cylinder is being replaced with great care, in reality, the packing is not installed properly, the nuts are not fastened properly, or the worker forgets to install the packing. It can happen.
In this state, gas may leak from the base and cause a dangerous situation. However, these connection failures cannot be detected merely by looking at the base. Therefore, conventionally, a leak check of the base portion is performed by various methods such as detecting gas leak by pressurizing the base portion using a gas such as helium, but it is difficult to perform a complete check, and There is a problem that it takes a considerable time for checking, for example, about one hour for each base of a special high-pressure gas cylinder. In addition, there is a problem that the leak cannot be constantly monitored.

An object of the present invention is to provide a connection mechanism between a gas cylinder and a gas pipe, which can reliably and easily detect a gas leak from a connection between the gas cylinder and the gas pipe.

[0010]

In order to achieve the above object, a connecting mechanism for connecting a gas cylinder to a gas pipe according to the present invention is characterized in that a gasket contact surface facing a gasket contact surface of a gas outlet nozzle of a gas cylinder has an annular surface at a tip end. A gas cylinder and a gas pipe which are provided with a base which is screw-connected to the gas outlet nozzle with the packing interposed between the two packing contact surfaces, and which connects the gas pipe to the gas outlet nozzle via the base. In the connection mechanism, the tip annular surface of the base is divided into an inner annular surface that functions as a packing contact surface and an outer annular surface that is stepped so as to be lower than the inner annular surface. Inert gas flow path having a gas outlet near the circumferential boundary with the outer annular surface,
An inert gas pipe that extends in the pipe wall of the gas pipe in the longitudinal direction and has a pressure gauge that measures the pressure of the inert gas in the inert gas flow path is connected to the inert gas pipe that supplies the inert gas. It is characterized by:

In the present invention, the tip annular surface of the base is divided into an inner annular surface functioning as a packing contact surface and an outer annular surface provided with a step so as to be lower than the inner annular surface. The gas outlet of the inert gas flow path through which
It is provided near the circumferential boundary between the inner annular surface and the outer annular surface of the base. So, forget to install the packing,
If the packing is improperly mounted or the base is not fastened, the inert gas leaks from the gas outlet through the space between the outer annular surface and the packing contact surface of the gas outlet nozzle of the gas cylinder. . As a result, the pressure of the inert gas in the inert gas flow path becomes lower than the supply pressure of the inert gas. Therefore, by monitoring the pressure of the inert gas in the inert gas flow path with a pressure gauge, the gas cylinder is monitored. Gas leak from the connection between the gas pipe and the gas pipe can be detected. The present invention is not limited to the type of gas cylinder and the type of gas stored in the gas cylinder, but can be applied, and can be applied by modifying an existing base.

Preferably, the pressure gauge constantly measures the pressure of the inert gas, and outputs a signal indicating that a pressure fluctuation exceeding a predetermined range occurs. This makes it possible to remotely detect a gas leak. In addition, the inert gas flow path has a plurality of gas outlets spaced along the circumferential boundary between the inner annular surface and the outer annular surface of the base near the boundary. Thereby, the gas leak can be reliably detected over the entire surface of the packing contact surface.
The type of the inert gas is not limited as long as it is safe and has low corrosiveness to gas piping, but nitrogen gas is preferable from the viewpoint of economy.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment the present embodiment is an example of embodiment of a connection mechanism between the gas cylinder and the gas pipe according to the present invention, FIG. 1 shows the configuration of a connection mechanism between the gas cylinder and the gas pipe of the embodiment FIG. 2 is a longitudinal sectional view showing the structure of the collar washer, and FIG. 3 is a front view of the collar washer taken along the line II-II in FIG. Of the parts and parts shown in FIGS. 1 to 3, the same parts as those shown in FIGS. 5 to 8 are denoted by the same reference numerals, and description thereof will be omitted. A connection mechanism (hereinafter simply referred to as a connection mechanism) 40 between a gas cylinder and a gas pipe according to this embodiment is a connection mechanism between the special high-pressure gas cylinder 10 and the gas pipe 26 described above by improving a conventional connection mechanism using a base. 1 to 3, as shown in FIGS. 1 to 3, provided with a base having the same configuration as the conventional base except for the configuration of the collar washer, and supplying nitrogen gas to the collar washer through a gas pipe. Means and a means for detecting the pressure of nitrogen gas,
It has the same configuration as the conventional connection mechanism.

As described above, the connection mechanism 4 of this embodiment is
Reference numeral 0 denotes a mechanism for connecting the gas pipe 26 to the gas outlet nozzle 16 of the special high-pressure gas cylinder 10 and includes a nitrogen gas supply unit and a pressure detection unit. The means for supplying nitrogen gas and the means for detecting pressure are, as shown in FIGS.
A nitrogen gas flow path 42, a distribution ring 44 for distributing nitrogen gas to the nitrogen gas flow path 42, a nitrogen gas pipe 46 for supplying nitrogen gas to the distribution ring 44, and a nitrogen gas pressure in the nitrogen gas pipe 46 are measured. And a pressure gauge 48 for outputting a pressure measurement value to a predetermined location. As shown in FIGS. 1 to 3, the nitrogen gas flow path 42
It is formed of four flow paths provided so as to penetrate the pipe wall of the gas pipe 26 in the longitudinal direction at an interval of °.

The collar washer 5 provided on the connection mechanism 40 is provided.
0 is a conventional packing contact surface 34 as shown in FIG.
7 and 8 extend outwardly from the annular groove 36 and the inner annular surface 52 between the protrusion 32 and the annular groove 36;
The outer annular surface 54 is lower than the inner annular surface by a height difference (H) of 0.05 mm, and the inner annular surface 52 functions as a packing contact surface. Four gas outlets 56 of the nitrogen gas flow path 42 are provided in the annular groove 36 so as to be separated by 90 °. In the present embodiment, the four gas outlets 56 are provided at equal intervals at 90 ° apart from each other because the nitrogen gas outlets are provided uniformly in the circumferential direction along the annular groove 36. This is for applying a nitrogen gas pressure to the packing 22. The pressure gauge 48 outputs the pressure fluctuation of the nitrogen gas as a contact output, and the output is processed as an interlock or an alarm.

In order to connect the special high-pressure gas cylinder 10 and the gas pipe 26 by the connection mechanism 40 of this embodiment,
As shown in FIG. 4A, the packing 22 is placed on the packing contact surface 20 of the gas outlet nozzle 16 and the collar washer 2
8 and the packing contact surface 52 of the collar washer 50 is inserted through the center hole of the packing 22.
Then, the base nut 30 is screwed into the gas outlet nozzle 16 and the connection mechanism 40 is mounted. The tightening torque of the base nut 30 is about 500 kgf / cm ² .

If the packing 22 is correctly mounted and the nut 30 is properly tightened, nitrogen gas leaks from the gas outlet 56 via the nitrogen gas flow path 42 as shown in FIG. Therefore, the pressure of the nitrogen gas measured by the pressure gauge 48 hardly drops below the supply pressure of the nitrogen gas. However, if the user forgets to install the packing 22, or the mounting condition of the packing 22 is bad, or the tightening condition of the base nut 30 is bad,
As shown in FIG. 4B, the nitrogen gas flows into the nitrogen gas flow path 42.
From the gas outlet 56 via As a result, the pressure of the nitrogen gas measured by the pressure gauge 48 is significantly lower than the supply pressure of the nitrogen gas. Therefore, by constantly monitoring the pressure of the nitrogen gas with the pressure gauge 48, the special high-pressure gas cylinder 10 is monitored.
When a gas leak occurs from the connection between the gas pipe 26 and the gas pipe 26, the gas leak can be detected immediately.
4 (a) and 4 (b) show the contact between the gas outlet nozzle 16 and the collar washer 50, respectively.
It is the schematic diagram which omitted 0.

In this embodiment, nitrogen gas is used as an inert gas for gas leak detection in consideration of contact with the gas flowing out of the special high-pressure gas cylinder 10 and safety of the surroundings when the gas flows out. Is considered.

[0019]

According to the present invention, the annular surface of the tip of the base is
A gas outlet of an inert gas flow path, which is divided into an inner annular surface that functions as a packing contact surface and an outer annular surface that is stepped so as to be lower than the inner annular surface, and through which an inert gas flows, is provided with a cap. It is provided near the circumferential boundary between the inner annular surface and the outer annular surface. Therefore, if the packing is forgotten, the packing is improperly mounted, or the base is not tightly tightened, the inert gas flows from the gas outlet to the packing between the outer annular surface and the gas outlet nozzle of the gas cylinder. Leaks through between surfaces. As a result, the pressure of the inert gas measured by the pressure gauge becomes lower than the supply pressure of the inert gas. By monitoring the pressure of the inert gas with the pressure gauge, the connection between the gas cylinder and the gas pipe is reduced. Gas leaks from the air can be detected.

More specifically, the effects of the present invention are as follows. (1) Gas leakage due to forgetting to install the packing is prevented. (2) When trying to open the cylinder main plug (open / close valve) without mounting the packing, it is possible to warn that the packing is not mounted. If there is an emergency shut-off valve, it can be prevented from opening by an interlock. (3) Gas leakage due to insufficient tightening of the base nut is prevented. When trying to open the cylinder stopper with insufficient tightening, it is possible to warn the user that it is insufficient. If there is an emergency shut-off valve, it can be prevented from opening by an interlock. Further, when the base nut is loosened during use, the cylinder main stopper can be closed by an interlock. (4) Looseness of the base nut due to deterioration of the packing during use can be detected, and unexpected gas leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a connection mechanism between a gas cylinder and a gas pipe according to an embodiment.

FIG. 2 is a partial longitudinal sectional view showing a configuration of a collar washer.

FIG. 3 is a front view of a color washer taken along a line II-II in FIG. 2;

FIGS. 4 (a) and 4 (b) are schematic views showing contact between a gas outlet nozzle and a collar washer, respectively, with a base nut omitted.

FIG. 5 is a perspective view showing a configuration of a connection mechanism connected to a gas pipe via a mouthpiece attached to a gas outlet of a special high-pressure gas cylinder.

FIG. 6 is an exploded view of a base.

FIG. 7 is a partial longitudinal sectional view of a collar washer.

8 is a front view of the color washer taken along the line II in FIG. 7;

[Explanation of symbols]

1 ... conventional connection mechanism, 10 ... special high pressure gas cylinder,
12 ... on-off valve, 14 ... gas outlet, 16 ... gas outlet nozzle, 18 ... thread, 20 ... packing contact surface, 22 ... annular packing (gasket), 24 ...
Base, 26 ... Gas piping, 28 ... Color washer, 29 ...
... Opening, 30 ... Base nut, 32 ... Protrusion, 34 ...
... packing surface, 36 ... annular groove, 40 ... connection mechanism between gas cylinder and gas pipe of the embodiment, 42 ... nitrogen gas flow path, 44 ... distribution ring, 46 ... nitrogen gas pipe, 48 ... Pressure gauge, 50: collar washer, 52: inner annular surface, 54: outer annular surface, 56: gas outlet.

Claims (5)

[Claims] 1. A base having a packing contact surface facing a packing contact surface of a gas outlet nozzle of a gas cylinder on a tip annular surface, and screwing to the gas outlet nozzle with a packing interposed between the two packing contact surfaces. In the gas cylinder and gas pipe connection mechanism, wherein the gas pipe is connected to the gas outlet nozzle through the base, the top annular face of the base is provided with an inner annular surface functioning as a packing contact surface and an inner annular surface. An inert gas passage having a gas outlet near the circumferential boundary between the inner annular surface and the outer annular surface of the base, and a gas pipe. It extends in the longitudinal direction in the wall, the inert gas flow path includes a pressure gauge that measures the pressure of the inert gas, and is connected to an inert gas pipe that supplies the inert gas. You Connection mechanism between the gas cylinder and the gas pipe. 2. The pressure gauge according to claim 1, wherein the pressure gauge constantly measures the pressure of the inert gas, and outputs a signal to that effect when a pressure fluctuation exceeding a predetermined range occurs. Connection mechanism between gas cylinder and gas pipe. 3. An inert gas flow path having a plurality of gas outlets spaced along a circumferential boundary between the inner annular surface and the outer annular surface of the base near the boundary. The connection mechanism between a gas cylinder and a gas pipe according to claim 1. 4. A connection mechanism between a gas cylinder and a gas pipe according to claim 1, wherein the annular groove is provided along a circumferential boundary between an inner annular surface and an outer annular surface of the base. . 5. The method according to claim 1, wherein the inert gas is nitrogen gas.
Connection mechanism between gas cylinder and gas pipe.