JP3016987U - Gas release prevention device - Google Patents

Abstract

(57) [Summary] [Purpose] When a valve body mounted on a gas container valve that contains LP gas or other high-pressure gas is damaged, abnormal gas release is shut off. [Structure] A connecting cylinder part for connecting a container valve provided on the other side of a valve body having a connection receiving part for connecting a pipe on one side, and an inside of the tip of an insertion cylinder having a locking flange on the outer periphery of the tip. A connecting hole provided inside the rear of the formed accommodating portion is formed up to the rear end, and the connecting hole is attached to the distal end portion having an insertion flange portion at the distal end of the insertion cylinder, and is inserted between the insertion flange portion and the locking flange portion. Attach the O-ring. A movable valve that closes the connection hole is housed in the housing portion of the insertion cylinder so as to be movable back and forth, and a gas flow passage is provided on the peripheral surface of the movable valve.
A rear end of a support rod whose front end is locked to the rear end of the movable body is fixedly attached between the rear part of the insertion cylinder and the connecting cylinder part of the valve body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas release prevention device that is attached to a gas container that contains LP gas or other high-pressure gas to prevent gas release.

[0002]

[Prior art]

 High-pressure gas such as flammable gas, combustion-supporting gas, and toxic gas could cause a fire or explosion if released in large amounts into the atmosphere, which was extremely dangerous. Therefore, as shown in FIG. 1, a pipe 6 is connected to a container valve 3 attached to a gas container 1 and having a handle 2 via a pressure regulator and a gas discharge preventer 5. In particular, the gas discharge preventer 5 attached to the LP gas container 1 blocks gas discharge caused by damage to the pipe 6 due to an external shock such as an earthquake. However, when a fallen object such as an earthquake or snow falls on the gas release preventer 5 and the connecting portion 4 of the valve body, especially on the gas container side is damaged, the conventional gas release preventer 5 functions. There is a problem in that the gas is released from the container valve 3 of the gas container and causes a fire or the like, which is dangerous.

[0003]

[Problems to be solved by the device]

 As described above, when the gas release preventer 5 connected to the connecting portion 4 of the container valve 3 attached to the gas container 1 is damaged by falling objects such as snowfall, fallen trees, falling rocks, etc., the gas release preventer 5 releases gas. When a person evacuated due to an earthquake during bedtime due to the release of gas, there was no one in the vicinity of the gas container, and the gas remained discharged, which was a fire and a secondary hazard, which was extremely dangerous. An object of the present invention is to prevent the gas from being released immediately when the gas is released due to damage to the connecting portion with the gas container due to a fallen object, damage to the piping, etc., and the gas container is greatly inclined. .

[0004]

[Means for Solving the Problems]

 According to the present invention, a tip of an insertion cylinder having a locking flange on the outer periphery of a tip is attached to a connecting cylinder for connecting a valve provided on the other side of a valve body having a connection receiving portion for connecting a pipe on one side. An accommodating chamber is formed inside, a connecting hole provided inside the rear of the accommodating chamber is provided, and a tip end portion having an insertion flange portion and a communication hole inside is attached to the tip end of the insertion cylinder. An O-ring is mounted between the insertion flange portion and the locking flange portion, and a check valve portion for closing the communication passage hole is provided in the front portion in the accommodation chamber of the insertion cylinder, and the connection hole is closed. A movable valve having a stop valve at the rear is housed so that it can move back and forth, a gas flow groove is provided on the peripheral surface, and a rear end of a support rod with its tip locked to the rear end of a movable body with a spring on the front side. Is fixed between the rear part of the insertion tube and the connection tube part, and has a connection screw part for connecting a container valve and a tightening part on the outer periphery of the insertion tube. Wherein the rotatably it is fitted with. Further, according to the present invention, a valve opening is formed in a lower portion of a passage provided inside a valve body having a connection receiving portion for pipe connection on one side, and a valve chamber is formed below the valve opening. The valve body and the guide portion for closing the valve body are integrally formed by the valve rod, and the valve body is arranged in the through hole and the valve chamber so as to be vertically movable, and the valve body is arranged so as to close the valve opening at a gas flow rate of a certain amount or more, Inside the lower lid attached to the lower end of the space provided below the valve chamber, a spring adjusted to slightly weaker strength than the vertical load of the actuating element springs from below, and the vertical load is dispersed by the tilt of the valve body. The connecting cylinder part for connecting the container valve, which is provided on the other side of the valve body that houses the actuating body that operates by A connecting hole is provided inside the rear part of the chamber, and a tip end having an insertion flange at the tip and having a communication through hole inside is inserted into the insertion tube. An O-ring is attached between the insertion flange portion and the locking flange portion at the end, and a check valve portion for closing the communication through hole is provided at the front portion in the accommodating chamber of the insertion cylinder. A movable valve having a rear portion of a stop valve portion for closing the connecting hole is housed so as to be movable back and forth, a gas flow groove is provided on the peripheral surface, and a front end is locked to a rear end of a movable body having a spring arranged at the front. The rear end of the supporting rod is fixed between the rear part of the insertion tube and the connection tube part, and the connection body having the connection screw part and the tightening part for connecting the container valve is rotated on the outer periphery of the insertion tube. It is characterized by being installed as much as possible. Further, according to the present invention, a window is provided on the wall surface of the valve body, and a guide portion for engaging with the lower end of a push rod having a push button fixed to the upper end is provided at the center of the upper body attached to the upper part of the valve body. It is housed in the passage so that it can move up and down, and has a valve element at the lower part of the guide part and a colored part is provided on the outer periphery of the guide part so that the colored part of the guide part can be seen from the window part. It is characterized by that.

[0005]

[Action]

 If the valve body connected to the container valve attached to the gas container is damaged by falling objects and falls off, the supporting rod will also fall off together with the valve body, and the movable body is housed in the insertion tube connected to the connection part of the container valve. A valve closes the connecting hole to prevent gas release. Further, when the gas container is largely tilted, the valve body is raised by the operation of the operating body to close the valve opening, thereby preventing gas release. Furthermore, if the gas flow rate through the valve opening increases due to damage to the piping connected to the gas container, gas overflow will occur at the valve opening, pushing up the valve body and closing the valve opening to prevent gas release. In addition, a window is formed on the wall of the valve body, and the operating state of the valve body can be easily confirmed by checking the colored part provided on the guide part accommodated in the inner passage so that it can move up and down. Can be determined.

[0006]

【Example】

 The first embodiment of the present invention will be described. Referring to FIG. 3, the second gas release prevention device 9 is connected to the connecting cylinder portion 41 provided on one side of the valve body 10 having the first gas release prevention device 8 built therein. I am doing it. The second gas release prevention device 9 is connected to a connecting portion 7a provided on one side of the container valve 7 attached to the opening of the gas container 1 as shown in FIG. In addition, the pipe 6 is connected to one side of the valve main body 10 in which the first gas release prevention device 8 is mounted. In FIG. 3, the first gas release prevention device 8 is formed below the small-diameter valve port 14 provided at the lower end of the flow path 13 provided at the lower part of the through hole 11 of the valve body 10 via the step portion 12. A large-diameter space 16 is provided below the valve chamber 15, and a lower lid 19 is fixed to the lower part of the space. A spherical actuating body 23 is accommodated on a vane 21 accommodated in the lower lid 19, and a slope portion 20a is provided on the upper portion of the lower lid. A guide 25, which is vertically movable in the through hole 11, and a valve body 27, which is accommodated in the valve chamber 15, are connected by a valve rod 26, and the valve body is provided with an O-ring for closing the valve opening. I'm wearing it. In this case, a gap 27a is provided between the valve body 27 and the actuating body 23 so that the valve body 10 does not immediately reach the valve body 27 even if the actuating body 23 moves due to a slight inclination.

A lid 33 is attached to an upper portion of the through hole 11 provided in the valve body 10, and a lower surface of the lid is provided below a push rod 35 which is vertically movably inserted through a hole provided at a center of the lid. A push piece 36 for locking the push button 38 mounted on the upper part of the valve body 10 is provided, and the upper end of the push rod 35 is fixed to the lower surface of the push button 38 mounted on the upper part of the valve body 10. It is raped between the body 33. On one side of the valve body, there is formed a connecting cylinder portion 41 for connecting a container valve having a through hole 42 communicating with the valve chamber 15, and on the other side, there is a large diameter connecting receiving portion 44. Is provided, an outflow port 45 communicating with the flow path 13 is provided, and an internal thread 43 is formed inside. When the pipe 6 or the like connected to the connection receiving portion 44 is cut to release the gas, the flow rate of the gas increases and the negative pressure generated at the valve opening 14 causes the valve body 27 to move upward and the valve opening. Close 14 When the valve body 10 is inclined and the vertical load applied to the actuating body 23 is dispersed, the vertical load applied to the spring 21 is reduced and the spring rebounds upward to move the actuating body 23 to the slope 20a. Then, the valve body 27 is pushed up, and the valve port 14 is closed to prevent gas emission. The tilt angle of the actuating body 23 is set so that it operates when tilted by about 30 to 45 degrees.

In FIG. 3, the second gas release prevention device 9 includes an insertion cylinder 51 having a locking flange 50 on the outer circumference of the female thread 40 of a connecting cylinder 41 provided on one side of the valve body 10. The male screw portion 52 provided at the rear part of the insertion tube is connected, and a small-diameter connection port 54 is provided to the rear end inside the storage chamber 53 provided inside the tip of the insertion tube, thereby forming a thin wall surface of the insertion tube. An exposed portion 51a is formed, and a slightly larger diameter recess 55 is formed on the rear end surface. On the outer circumference of the insertion cylinder 51, a connection body 58 having a connecting screw portion 56 on the outer circumference of the tip and a tightening portion 57 having a large diameter on the rear portion is rotatably mounted. A front end portion 61 having a slightly larger diameter insertion flange portion 60 at the front end is screwed to the portion, and an O-ring 62 is mounted between the insertion flange portion 60 and the locking flange portion 50. The taper surface 64 is formed with the rear end of the communication hole 63 provided at the center of the. A movable valve 65 is housed in the accommodating chamber 53 of the insertion cylinder so as to be movable back and forth, and a check valve portion 65a provided with an o-ring for closing the communication hole 63 is provided at the front portion of the movable valve. A spring 71 is repulsed between the portion 61 and the movable valve 65. Further, an O-ring is attached to the rear portion of the movable valve 65 so that the connecting hole 54 is closed by a stop valve portion 66 having a slightly smaller diameter. A blind hole 68 formed at the rear end of a movable valve 65 having a plurality of gas flow grooves 67 on its peripheral surface is provided with a ring 70 formed at the rear end of a support rod 69 made of wire or the like with its tip engaged. 55 and the inner end of the connecting cylinder portion 41 of the valve body.

If a falling object such as snow falls on the second gas release prevention device 9 and the exposed portion 51a, which is thin in thickness and weak in strength, of the insertion cylinder 51 connected to the connecting cylinder portion 41 is damaged. As shown in FIG. 4, the valve body 10 falls off from the connecting portion 7a of the container valve 7. Since the ring 70 is held by the inner end of the connecting cylinder part 41 and the rear part of the insertion cylinder, the support rod 69 also falls off together with the valve body, and the movable valve 65 in the accommodating chamber 53 is inserted from the communication through hole 63. The stop valve portion 66 of the movable valve closes the connecting hole 54 by moving backward due to the gas pressure to prevent gas discharge. The second gas release prevention device 9 does not operate unless the insertion tube 51 connected to one side of the first gas release prevention device 8 breaks and the support rod 69 falls off, and the configuration thereof is extremely simple. Because the cost is low and no breakdown occurs. Further, in order to replace the gas container 1, when the connecting body 58 is removed from the connecting portion 7a, the gas remaining in the pipe 6 flows backward, and the movable valve 53 in the storage chamber 53 moves forward against the spring. Then, the check valve portion 65a can close the communication through hole 63 and prevent gas leakage from the communication through hole.

The second embodiment shown in FIG. 5 will be described. The same reference numerals as those used above indicate the same items. A second actuating body 23a made of a synthetic resin material and formed in a cylindrical shape is housed inside the lower lid 19 so as to be vertically movable, and an upper recess 23b and a lower recess 23c are provided above and below the actuating body, respectively. The spring 21a is housed in the lower recess 23c. The valve body 27 loosely fitted in the upper recess 23b of the actuating body 23a is located in the valve chamber 15 below the valve opening 14. In this case, since the gap 27a is provided between the lower end of the valve body 27 and the bottom of the upper concave portion 23b of the actuation body, even if the actuation body 23a moves a little, it should not be applied to the valve body 27 immediately. is there. When the valve body 10 is normally positioned and the pipe 6 or the like is broken, the flow rate of gas increases, and the negative pressure generated above the valve body 27 raises it to close the valve port 14. In this case, since the vertical load of the actuating body 23a does not change, the spring 21a is compressed. When the valve body 10 attached to the gas container is largely tilted, the center of gravity of the valve body 27 is moved, and the operating body 23a attached to the lower lid 19 is also tilted, and the vertical load applied to the operating body 23a is dispersed and reduced. Then, the actuating body 23a is raised by the elastic force of the spring 21a adjusted to overcome the reduced vertical load, and the valve body 27 is raised to close the valve opening 14 to release gas. The valve chamber 15 shuts off.

If the gas releasing device 9 is attached to the insertion tube 51 connected to the connection tube portion 41 of the valve body, the wall thickness of the insertion tube 51 connected to the connection tube portion 41 due to falling objects such as snow will be small. The exposed portion 51a, which is weak in strength, is most likely to be damaged. When the insertion cylinder 51 is damaged from the exposed portion 51a, the valve body 10 separates from the connecting portion of the container valve and falls, but the ring 70 is held by the connecting cylinder portion 41 and the rear end of the insertion cylinder 51. Therefore, the support rod 69 also drops together with the valve body, the movable valve 65 accommodated in the accommodating chamber 53 of the insertion cylinder moves rearward due to the gas pressure from the communication hole 63, and the stop valve portion 66 of the movable valve is changed. The connection hole 54 is closed to prevent outgassing.

The third embodiment shown in FIG. 6 will be described. The same reference numerals as those used above indicate the same items. A mortar-shaped slope portion 20a is formed on the inner bottom surface of a lower lid 19 fixed to the lower portion of a space 16 formed below the valve chamber 15 provided below the valve body 10, and a spherical third portion is formed in the slope portion. The actuating body 23 is housed. A push rod 35 is vertically movably inserted into a hole provided at the center of a lid 33 attached to the upper portion of the through hole 11 of the valve body 10, and a stopper 35a provided in the middle of the push rod 35 having a push button 38 attached to the upper end. The guide portion 25 and the guide portion 25 are spring-loaded by a spring 39a. A rod-shaped valve body 26 attached to the lower portion of the guide portion 25 housed in the through hole 11 is inserted into the valve opening 14, and upper and lower small openings 26c and a lower portion are provided at the upper and lower portions of the communication hole 26a provided inside the valve body 26. A small opening 26d is formed, a seal ring is attached to the lower portion of the valve element 26, and the operating element 23 is attached to the lower end of the valve element 26 via a gap 27a. Then, when the pipe 6 or the like is damaged, the valve body 27 is raised to close the valve port 14 as in the case of the first and second embodiments. When the valve body 10 attached to the gas container is tilted, the actuating body 23 moved along the slope 20a provided on the lower lid 19 is lifted to push up the valve body 27 and close the valve opening 14 to release the gas. Is shut off by the valve chamber 15.

If the second gas releasing device 9 is attached to the insertion cylinder 51 connected to the connection cylinder portion 41 of the valve body, the insertion cylinder 51 is connected to the connection cylinder portion 41 due to a fallen object such as snow. The exposed portion 51a, which is thin in thickness and weak in strength, is most likely to be damaged. When the insertion cylinder 51 is damaged from the exposed portion 51a, the valve body 10 separates from the connection portion 7a of the container valve 7 and falls, but the ring 70 is separated between the inner end of the connection cylinder portion 41 and the rear end of the insertion cylinder 51. Since it is held, the support rod 69 also drops together with the valve body 10, and the movable valve 65 accommodated in the accommodating chamber 53 of the insertion cylinder moves rearward due to gas pressure to stop the movable valve 65. The connection hole 54 is closed with to prevent gas release.

The fourth embodiment shown in FIG. 7 will be described. The same reference numerals as those used above indicate the same items. The slope 20a provided on the lower lid 19 attached to the lower portion of the valve chamber 15 provided at the lower portion of the valve body 10 accommodates the fourth actuating body 23d having the shaft portion 23f at the upper portion. When the pipe is damaged, the valve body 27 rises and the valve port 14 is closed by the gas excess flow generated at the valve port 14 as in the case of the first and second embodiments. Further, when the gas container 1 falls over or is greatly inclined and the valve body 10 is inclined, the actuating body 23d moves along the slope of the slope 20a, and the shaft 23f of the actuating body pushes up the valve body 27. To close the valve opening 14. If the second gas releasing device 9 is attached to the insertion cylinder 51 connected to the connection cylinder portion 41 of the valve body, the insertion cylinder 51 is connected to the connection cylinder portion 41 due to a falling object such as snow. The exposed portion 51a, which is thin and weak in strength, is most likely to be damaged. When the insertion cylinder 51 is damaged from the exposed portion 51a, the valve body 10 separates from the connection port 7a of the container valve and falls, but the ring 70 is held by the inner end of the connecting cylinder portion 41 and the rear end of the insertion cylinder 51. Therefore, the support rod 69 also drops together with the valve body, and the movable valve 65 accommodated in the accommodating portion 53 of the insertion cylinder moves due to the gas pressure from the communication hole 63, thereby stopping the movable valve. The connection hole 54 is closed at the portion 66 to prevent gas emission.

In FIGS. 8A and 8B, the transparent body 60 is attached to the window portion 10 a provided on the side wall of the valve body 10 so that the inside can be seen, and the outer circumference of the guide portion 25 housed in the through hole 11 of the valve body 10. A colored portion 25a that stands out is provided on the surface. Above the guide portion 25, a push button having a push rod 35 at the lower portion is pushed down, and then a spring 39a is elastically urged between the interior 25 and a stopper 35a provided on the push rod 35 in order to return to the ascended state. The push button is always pushed upward. When the valve port 14 is opened and the gas is normally supplied, the colored portion 25a is not located in the window 10a. However, when the pipe 6 is broken or the gas container is tilted at a certain angle (30 to 45 degrees) or more, the operation of the actuating body pushes up the valve body 27 to close the valve opening 14 and prevent gas release. However, when the valve body 27 rises, the guide portion 25 also rises at the same time, and the colored portion 25a provided on the outer peripheral surface of the guide portion is located in the window portion 10a. The open / closed state can be easily identified. Since the confirmation of the colored portion 25a of the guide portion from the window portion 10a is carried out in all of the first to fourth embodiments, it has a convenient gas release preventing function.

When the valve opening 14 is closed by the valve body 27, the valve opening 14 remains closed due to the gas pressure from the gas container. That is, even if the valve body 10 is restored to the normal position, the valve body 27 does not descend due to its own weight and the valve opening 14 is closed. Therefore, the handle of the container valve 7 is rotated and once closed to release the gas from the gas container. Stop the spill. Then, the push button 38 mounted on the upper part of the valve body 10 is pushed down against the spring 39, the guide portion 25 and the valve body 27 are pushed down, and the valve port 14 can be opened.

[0017]

Advantageous Effects of Invention According to the first aspect of the invention, due to falling objects such as snow, a connecting body connected to a container valve connected to a gas container remains, and a valve body having a valve mechanism for stopping gas falls off. In this case, the movable valve in the insertion cylinder is activated to prevent gas release from the gas container, which is extremely safe. According to the second aspect of the invention, when the valve body is inclined together with the gas container at a certain angle or more, or when the piping portion is damaged and an overflow of gas occurs inside, the gas release can be blocked by the valve body. In addition, it is extremely safe because it is possible to reliably block the gas release that would occur if the connecting part of the valve body on the gas container side is broken. The side wall of the valve body is provided with a window through which the inside can be observed, and the coloring formed on the guide unit integrated with the valve body that is vertically accommodated in the through hole provided on the valve body or the push rod provided on the push button. By checking the parts, the operating state of the valve body can be easily determined from the outside, and a gas release prevention device with good usability can be provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a gas overflow prevention device in which a conventional gas release preventer is provided integrally with a container valve.

FIG. 2 is a front view showing a piping state with a part of the valve attached to a container valve connected to a gas container according to the present invention.

FIG. 3 is a cross-sectional view of a second gas release preventing device mounted on a connecting cylinder portion for connecting a container valve of a valve body having a first gas release preventing device according to a first embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a main part in a state where a second gas release prevention device is activated.

FIG. 5 is an overall vertical sectional view showing a second embodiment.

FIG. 6 is an overall vertical sectional view showing a third embodiment.

FIG. 7 is an overall vertical sectional view showing a fourth embodiment.

FIG. 8 shows a valve operation confirmation device provided in the valve body, FIG. 8A is an enlarged cross-sectional view of an essential part showing a valve open state, and FIG. 8B is an enlarged cross-sectional view of an essential part showing a valve closed state.

[Explanation of symbols]

 7 Container Valve 8 First Gas Release Prevention Device 9 Second Gas Release Prevention Device 10 Valve Main Body 10a Window 11 Through Hole 14 Valve Port 15 Valve Chamber 16 Space 19 Lower Lid 20 Slope 21 21 Spring 23 Actuator 25 Guide 25a Coloring part 26 Valve rod 27 Valve body 33 Lid body 35 Pushing rod 38 Push button 39 Axial spring 41 Connecting cylinder part 44 Connection receiving part 50 Locking flange part 51 Inserting cylinder 51a Exposed part 53 Storage chamber 54 Connecting hole 56 Connecting screw part 57 Tightening part 58 Connection body 60 Insert flange part 61 Tip cylinder 62 O-ring 63 Communication through hole 65 Movable valve 67 Communication groove 69 Support rod

Claims (3)

[Scope of utility model registration request] 1. A tip of an insertion tube having a locking flange on the outer circumference of a connecting cylinder portion for connecting a container valve provided on the other side of a valve body having a connection receiving portion for pipe connection on one side. An accommodating chamber is formed inside, a connecting hole provided inside the rear of the accommodating chamber is provided, and a tip end portion having an insertion flange portion and having a communication hole inside is attached to the tip end of the insertion cylinder. An O-ring is mounted between the insertion collar portion and the locking collar portion, and a check valve portion for closing the communication through hole is provided at the front portion in the accommodating chamber of the insertion cylinder.
A movable valve having a rear portion of a stop valve portion for closing the connecting hole is housed so as to be movable back and forth, and a tip is locked to a rear end of a movable body having a gas flow groove on a peripheral surface and a spring arranged on the front side. The rear end of the support rod is fixed between the rear part of the insertion tube and the connection tube part, and the connection body having the connection screw part and the tightening part for connecting the container valve on the outer periphery of the insertion tube can be rotated. A gas release prevention device characterized by being attached to the. 2. A valve opening is formed in a lower portion of a passage provided inside a valve body having a connection receiving portion for connecting a pipe on one side, and a valve chamber is formed below the valve opening. A valve body and a guide portion for closing the valve body are integrally formed by a valve rod, and the valve body is arranged in the through hole and the valve chamber so as to be vertically movable, and the valve body is arranged so as to close the valve opening at a gas flow rate of a certain level or more, Inside the lower lid attached to the lower end of the space provided below the valve chamber, a spring adjusted to have a slightly weaker strength than the vertical load of the actuating element springs from below, and the vertical load is dispersed due to the inclination of the valve body. The connecting cylinder part for connecting the container valve on the other side of the valve body accommodating the actuating body that operates by A connecting hole is provided inside the rear part of the chamber, and a tip having an insertion flange at the tip and a communication hole inside is attached to the tip of the insertion tube. An O-ring is attached between the insertion flange portion and the locking flange portion, and a check valve portion for closing the communication through hole is provided at the front portion in the accommodation chamber of the insertion cylinder.
A movable valve having a rear portion of a stop valve portion that closes the connection hole is housed so as to be movable back and forth, a gas circulation groove is provided on the peripheral surface, and a tip is locked to a rear end of a movable body having a spring arranged in the front. The rear end of the supporting rod is fixed between the rear part of the insertion tube and the connection tube part, and a connection body having a connection screw part and a tightening part for connecting a container valve is rotated on the outer periphery of the insertion tube. A gas release prevention device characterized by being installed as much as possible. 3. A valve body is provided with a window portion on a wall surface thereof, and at the center of an upper body attached to the upper portion of the valve body,
A guide portion that locks with the lower end of a push rod having a push button fixed to the upper end is housed in the passage so as to be vertically movable, and a valve element is provided at the lower portion of the guide portion and a colored portion is provided on the outer periphery of the guide portion. The gas release prevention device according to claim 1 or 2, wherein a colored portion of the guide portion is provided so as to be visible from the window portion.