JPH0741200U - Dry cutout - Google Patents

Abstract

(57) [Abstract] [Purpose] [Structure] A dry cutout 4 is branched and connected to a gas pipe 1 provided with an emergency shutoff valve 3 and a governor 2. This safety device 4
Is the first relief valve mechanism 6 which operates at a low stage predetermined pressure P1 which is lower than the set pressure P2 of the emergency shutoff valve 3 to release a small amount of the gas in the gas pipe 1 to the atmosphere, and the set pressure P2. A second relief valve mechanism 7 that operates at a high high stage predetermined pressure P3 to release a large amount of gas to the atmosphere. [Effect] The pressure rise in the gas pipe 1 is prevented. In particular, when the pressure rise is small, a small amount of gas is released, which is excellent in safety and loss reduction. Further, since water is not used as the sealing material, labor saving in maintenance can be achieved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dry cutout device used in a piping system that regulates and supplies gas such as city gas that requires a safety system.

[0002]

[Prior art]

 A main part of a city gas piping system, which is an example of a conventional pressure regulation supply system, is schematically shown in FIG. In FIG. 13, the gas pipe 1 realized by the gas pipe is provided with an emergency shutoff valve (ESV) 3 and a governor 2 in series from the upstream side based on the flow direction of the gas in the pipe. 2 is branched on the downstream side and the safety device 5 is connected. These pipe members form a pressure regulation and safety supply system. The governor 2 functions as a pressure regulator so as to maintain the gas pressure in the pipe on the downstream side at a constant value, and the ESV 3 operates when the pressure in the pipe system abnormally rises due to a failure of the governor 2 or the like, and shuts off the pipe 1. Stop gas supply for safety.

The safety device 5 is provided to further enhance safety and to release a pressure increase due to a rise in temperature when the governor 2 is deactivated. In other words, if the ESV 3 does not operate for some reason, the safety device 5 can relieve the gas, thereby reducing the pressure. In this way, the combination of the ESV 3 and the safety device 5 can cope with the abnormal pressure increase due to the failure of the governor 2 and the safety is ensured. Further, due to the structure of the governor 2, when the flow rate of the gas decreases, the governor 2 is in an operation stopped state in which the secondary side is closed. At this time, if the temperature and the atmospheric pressure rise, the ESV 3 may operate even if there is no abnormality. It is also necessary to prevent such a situation.

The structure of a conventional water-sealed cutout 5 is schematically shown in FIG. In FIG. 14, a main body 51 made of a hermetically sealed container is divided into two chambers on the left and right by a partition 53, and an exhaust pipe 52 is inserted in the chamber on the left side in the figure airtightly through the top wall. The lower end of the pipe to the middle layer of the left chamber. A pipe connection port 55 is provided on the top wall of the left chamber, and a branch pipe from the pipe 1 is connected to the pipe connection port 55. The left and right chambers are communicated with each other through a gap adjacent to the lower end of the partition 53, and an appropriate amount of water 56 is stored in both chambers.

In the cutout 5 having the above-mentioned structure, the city gas pressure of 210 mm water column is normally applied to the liquid surface in the left chamber of the main body 51 via the pipe connection port 55, and the lower end opening of the exhaust pipe 52 is opened. The small hole 54 provided in the pipe wall immediately above and the water is sealed by water 56. Therefore, the exhaust pipe 52 for opening to the atmosphere is in a closed state. When the gas pressure in the pipe 1 rises for some reason, the liquid level in the left chamber drops and becomes lower than the small hole 54, and the gas passes from the small hole 54 through the exhaust pipe 52. The rise in pressure is suppressed because it is released into the atmosphere in small quantities. When the gas pressure further rises, the liquid level drops below the lower end opening of the exhaust pipe 52, and a considerable amount of gas is released into the atmosphere through the exhaust pipe 52, so the pressure does not rise. As described above, the safety device 5 may operate not only when the ESV 3 does not operate, but also when the daily pressurization occurs when the temperature and the atmospheric pressure around the pipe 1 increase due to no gas demand.

[0006]

[Problems to be solved by the device]

 In the conventional pressure regulation / safety supply system, the ESV3 is operated unnecessarily, so that the gas supply is temporarily stopped, which is inconvenient for the user, which is not preferable. On the other hand, by using the water-sealed cutout 5 and adjusting the set pressure, it is possible to minimize the shut-off operation of the ESV 3 to suppress the pressure rise and improve safety. The water-sealed safety device is large, heavy and expensive, and it is necessary to check and manage the water volume at all times, which is problematic in terms of versatility. There is also a problem in practical use such as difficult installation in a room.

The purpose of the present invention is to improve the safety of the pressure regulation / safety supply system in the gas supply line, and to improve the versatility by realizing low cost and compactness. It is to provide a safety device.

[0008]

[Means for Solving the Problems]

 According to the present invention, an emergency shut-off valve and a governor are connected in series, and in the middle of a gas pipe, a branch connection is made downstream of the governor so that a set pressure of two or more stages is used without using a liquid as a sealing material. It is a multi-stage actuated dry cutout valve that operates at a low pressure, which operates at a low stage specified pressure that is lower than the set pressure of the emergency shutoff valve and which is equivalent to the daily pressure increase. The first relief valve mechanism that releases to the first relief valve mechanism and the emergency relief valve that operates at a high-stage predetermined pressure that is a value corresponding to a higher warning pressure than the set pressure, and is larger than the release amount by the first relief valve mechanism. And a second relief valve mechanism for discharging the gas to the atmosphere.

In addition, the present invention provides a two-stage branch without using a liquid as a sealing material, which is branch-connected downstream of the governor in the middle of a gas pipe provided with an emergency shutoff valve and a governor connected in series. It is a multi-stage dry type safety device that operates at the above set pressures.It operates at a low stage specified pressure equal to or lower than the preset pressure of the emergency shutoff valve, which is equivalent to the daily pressure increase, and operates in the gas pipe. A first relief valve mechanism that releases a small amount of gas to the atmosphere, and operates at a high pressure higher than a predetermined high pressure that is lower than the preset pressure of the emergency shutoff valve and higher than the low predetermined pressure. And a second relief valve mechanism that releases a larger amount of the gas to the atmosphere than the amount released by the first relief valve mechanism.

[0010]

[Action]

 According to the present invention, a multistage actuated dry cutout device that releases gas by valve operation instead of the liquid ring system is constructed. This dry cutout device is used by branching in the middle of gas pipes such as city gas pipes. When the inside of the pipe reaches a low stage predetermined pressure equivalent to the daily pressure increase during use, the first relief valve mechanism operates and releases a small amount of gas in the pipe to the atmosphere. Therefore, the boosting is suppressed and the malfunction of the ESV is prevented.

If the internal pressure of the pipe further rises abnormally due to a governor failure or the like and becomes higher than a predetermined high pressure corresponding to the warning pressure, the second relief valve mechanism operates to release a sufficient amount of gas in the pipe to the atmosphere. To do. As a result, the internal pressure of the pipe is prevented from rising excessively and safety is improved. It is possible to realize a dry type safety device that maintains and improves the supply reliability while operating in multiple stages by using the first relief valve mechanism and the second relief valve mechanism instead of the liquid ring system, so low cost, Can be made compact.

According to the invention, the first and second relief valve mechanisms release the gas in the gas pipe to the atmosphere in two steps. If the gas to be released is city gas, it is not preferable to release a large amount at one time. If it is a daily pressurization, a small amount of release can be used.

[0013]

【Example】

 FIG. 1 schematically shows a pressure regulation / safety supply system for a gas pipe 1 such as a city gas pipe in which an embodiment of the present invention is used. The gas pipe 1 is provided with an ESV 3 and a governor 2 connected in series from the upstream side based on the flow direction of the gas in the pipe, and the present invention is provided at the end of the pipe branched and connected on the downstream side of the governor 2. The dry cutout 4 according to the embodiment is connected. The dry cutout 4 is configured to include a first relief valve mechanism 6 and a second relief valve mechanism 7, and the set pressures P1 and P3 of both the relief valve mechanisms 6 and 7 are set with respect to the set pressure P2 of ESV3. , P1 <P2 <P3 are established so that a two-stage relief operation is performed against the daily pressurization phenomenon that changes due to an increase in temperature or pressure of the surrounding environment. Each set pressure is determined.

FIG. 2 shows in a pressure diagram the mode of operation of the system of FIG. When the pipe internal pressure becomes equal to or higher than the set pressure P1 due to daily pressurization, the dry safety device 4 operates as described above at time t1 in FIG. Releases air into the atmosphere to prevent internal pressure rise. When the pipe internal pressure further rises and exceeds the set pressure P2, as shown at time t2 in FIG. 2 (B), the ESV3 operates and shuts off. As a result, the pressure of the gas pipe 1 on the downstream side of the ESV3 increases. descend. In this case, when the internal pressure of the pipe further increases due to a failure of the ESV3 and becomes equal to or higher than the set pressure P3, the second relief valve mechanism 7 operates and a sufficient amount is reached as shown at time t3 in FIG. 2 (C). The gas of is released into the atmosphere. Therefore, the abnormal rise in the pipe pressure is prevented by the operation of the dry cutout 4. It is also possible to set as P3 <P2. In this case, two-step relief operation is performed before the operation of ESV3. For daily pressurization, a small amount is released at P1 and a large amount is released at P3 only when necessary. This can suppress the operation of ESV3 as much as possible. When ESV3 operates, the supply of gas to the downstream side is stopped and it takes time to recover.

FIG. 3 functionally shows the structure of the dry cutout device 4 according to the first embodiment of the present invention. (A) is a non-operating state, (B) is a first stage relief operating state, (C) Is schematically shown when the second-stage relief operation is performed, and (D) is a beveled appearance of the valve body 9. The dry cutout 4 shown in FIG. 3 includes a casing 8, a valve body 9, a valve rod 10 and a diaphragm 12. The casing 8 is provided with a valve seat 11 having a circular hole in the bottom wall and a circular hole in the top wall. A diaphragm 12 is attached to the circular hole of the top wall so as to be airtightly closed, while a circular valve body 9 having a cylinder shape is kept airtight in the circular hole of the valve seat 11. Is slidably installed. The valve body 9 is formed in a topped cylindrical body, and a plurality of small holes 14 are bored on the side near the top wall of the peripheral surface portion so as to divide the circumference equally, and on the side far from the top wall, A plurality of slit holes 15 are similarly formed at equal distribution positions. The size of each hole is determined so that the total opening area of the slit holes 15 is larger than the total opening area of the small holes 14.

The valve body 9 having such a structure is connected to the central portion of the diaphragm 12 by the valve rod 10 and slides up and down in the valve seat portion 11 in conjunction with the vertical movement of the diaphragm 12. In the diaphragm 12, the connecting portion of the valve rod 10 is supported by a spring 13 at an appropriate position of the casing 8. In the state where the weight of the valve body 9 and the elastic force of the spring 13 are balanced and the valve chamber in the casing 8 is kept at a normal pressure, as shown in FIG. 11 is airtightly closed by the top wall portion of the valve body 9, and an inactive closed state is maintained.

When the valve chamber in the casing 8 is boosted to the set pressure P1, the diaphragm 12 is deformed in an upward convex shape in response to this increase in pressure, and the valve element 9 is displaced upward in conjunction with this. Due to this displacement, the portion where the small hole 14 is provided enters the valve chamber above the valve seat portion 11. As a result, the valve chamber communicates with the atmosphere through the small hole 14 and the space inside the valve body 9, so that a small amount of the valve chamber gas corresponding to the total opening area of the small hole 14 is released into the atmosphere. The gas releasing operation in this case corresponds to the relief operation of the first relief valve mechanism 6, and is as shown in FIG. 3 (B).

When the pressure in the valve chamber in the casing 8 further rises and exceeds the set pressure P3, the diaphragm 12 is further deformed to a convex shape upward, and in conjunction with this, the valve body 9 moves further upward. Displace. As a result of this displacement, as shown in FIG. 3 (C), the portion where the slit hole 15 is provided enters into the valve chamber, and as a result, the valve chamber includes the small hole 14, the slit hole 15, and the space inside the valve body 9. Through the atmosphere. Therefore, a large amount of gas in the valve chamber corresponding to the total opening area of both holes 14 and 15 is released into the atmosphere. The gas releasing operation in this case corresponds to the relief operation of the second relief valve mechanism 7. When the cause of the pressurization goes away and the pressure in the valve chamber falls to the normal pressure, the restoring operation is performed in the order of FIG.

FIG. 4 functionally shows the structure of a dry cutout device 4 according to a second embodiment of the present invention. (A) is a non-operating state, (B) is a first stage relief operating state, and (C) is a The second stage relief operation is shown respectively. In the dry safety device 4 shown in FIG. 4, a casing 8 is formed by a diaphragm chamber 16 and a valve chamber 17 which are located above and below each other and are independent of each other. The diaphragm chamber 16 includes a diaphragm 11 and a pressure setting spring 13. On the other hand, in the valve chamber 17, the first valve seat portion 11A corresponding to the first relief valve mechanism 6 is located at the bottom wall portion, and the second valve seat portion 11B corresponding to the second relief valve mechanism 7 is located at the top position just above it. It is provided on each wall.

The first valve seat portion 11A is provided with an opening having a small diameter, and a first valve 18 for opening and closing the hole is provided directly above and movable in the vertical direction. The second valve seat portion 11B is provided with a hole having a diameter larger than that of the hole of the first valve seat portion 11A. A second valve 19 is provided in contact with the large-diameter hole from above, and a spring 20 attached to a fixed portion 23 acts on the second valve 19 and normally the second valve 19 is provided. Closes the second valve seat portion 11B with a constant spring force. Both valves 18 and 19 are integrally connected to the diaphragm, and are arranged in relation to the valve rod 10 vertically movably provided. The first valve 18 is directly fixed to the lower end portion of the valve rod 10, and the second valve 19 is displaced by a flexible seal member 21 attached to the valve rod 10 in a relatively long vertical direction. It is possible to be locked. A push-up valve plate 22 is fixed to the valve rod 10 so as to be positioned below the second valve 19 so as to contact the lower surface of the second valve 19 when the valve rod 10 moves upward by a predetermined stroke. Upon contact, the valve 19 is pushed up to open the hole of the second valve material portion 11B.

In such a dry cutout 4, the diaphragm chamber 16 and the valve chamber 17 are branched and connected to the city gas pipe 1 so that the inside pressure of the dry cutout device 4 is equal to that of the pipe. As shown in FIG. 4A, when the inside of the pipe 1 is maintained at a normal pressure, both the first valve 18 and the second valve 19 are closed and inoperative.

When the inside of the diaphragm chamber 16 is raised to the set pressure P1, the diaphragm 12 is displaced upward due to the rising pressure, and accordingly, the valve rod 10 is lifted. As a result, since the first valve 18 opens, the inside of the valve chamber 17 communicates with the atmosphere through the small hole of the first valve seat portion 11A, and a small amount of the valve chamber corresponding to the opening area of the small hole. Gas (city gas) is released into the atmosphere. The gas releasing operation in this case corresponds to the relief operation of the first relief valve mechanism 6, and is in the state shown in FIG. 4 (B).

When the pressure in the diaphragm chamber 16 further rises and exceeds the set pressure P3, the diaphragm 12 is further displaced in the ascending direction, and in conjunction with this, the push-up valve plate 22 rises and the second Push up valve 19. The displacement of the second valve 19 causes the second valve seat portion 11B to open, as shown in FIG. 4C, and the inside of the valve chamber 17 communicates with the atmosphere through the large-diameter hole. . Therefore, the valve chamber 17 communicates with the atmosphere through the small hole of the first valve seat portion 11A and the hole of the second valve seat portion 11B, and a sufficient amount of gas corresponding to the total opening area of both holes is released into the atmosphere. It The release operation in this case corresponds to the relief operation of the second relief valve mechanism 7.

FIG. 5 functionally shows the structure of the dry cutout device 4 according to the third embodiment of the present invention. FIG. 5A is an overall structural view when it is not in operation, and FIGS. 5B and 5C. [Fig. 4] is a partial valve structure diagram of the first-stage and second-stage relief operations. The embodiment shown in FIG. 5 is similar to the second embodiment shown in FIG. 4, and the corresponding portions bear the same reference numerals. What should be noted in the embodiment shown in FIG. 5 is that the valve portion has a two-stage structure. That is, a valve formed by combining the first valve 18 and the second valve 19 in two concentric stages is arranged corresponding to one valve seat portion 11, and the first valve 18 has a donut plate shape. It is provided so as to be vertically displaceable so that it can be moved toward and away from the valve seat portion 11. Further, the second valve 19 is large enough to close the circular hole provided in the central portion of the first valve 18 and has a disk shape smaller than that of the first valve 18. It is arranged directly above the first valve 18 via the material 27 so that the first valve 18 can be polymerized while maintaining airtightness. Further, the second valve 19 is attracted to the first valve 18 by the connecting spring 28, and normally, as shown in FIG. 5 (A), both valves 18 and 19 are hermetically polymerized.

The valve chamber 17 has a valve accommodating portion having a convex vertical cross-section that surrounds the valve seat portion 11 above the valve seat portion 11. The valves 18 and 19 are housed in the valve housing so as to be displaceable in the vertical direction, and the first vent port 24 is opened in the lower part and the second valve is opened in the upper part on the peripheral wall part thereof. The air outlet 25 is opened, and a stopper wall 26 is provided between the air outlets 24, 25.

The dry cutout 4 having such a structure has the first valve 18 and the first valve 18 as shown in FIG. 5A when the city gas pipe 1 is kept at a normal pressure. The second valve 19 and the second valve 19 are airtightly overlapped with each other, the first valve 18 is in contact with the valve seat portion 11 and is in a closed state, and is inoperative.

When the inside of the diaphragm chamber 16 and the inside of the valve chamber 17 are raised to the set pressure P1, the diaphragm 12 and both valves 18 and 19 are displaced upward by interlocking with this pressure increase. As a result, the first valve 18 is displaced to a position slightly above the first air outlet 24 and enters a state as shown in FIG. 5 (B). A gas such as a small amount of city gas corresponding to the opening area of the first air outlet 24 is released into the air by communicating with the air through the first air outlet 24. The state of gas release shown in FIG. 5B corresponds to the relief operation of the first relief valve mechanism 6.

When the pressure in the diaphragm chamber 16 and the valve chamber 17 further rises and exceeds the set pressure P3, the diaphragm 12 is further displaced upwards, and in conjunction with this, the second valve 19 is displaced upwards. 2 Displaced to a position slightly above the air outlet 25. On the other hand, the first valve 18 also moves upward in conjunction with the same purpose, but when it comes into contact with the stopper wall 26, it stops moving and does not rise any further, and as a result, the first valve 18 and the second valve 19 Are separated from each other and the state shown in FIG. Therefore, in addition to the state in which the inside of the valve chamber 17 communicates with the atmosphere through the first vent port 24, the circular hole in the central portion of the first valve 18, the gap between the first valve 18 and the second valve 19, and The second air outlet 25 communicates with the atmosphere, and a sufficient amount of air corresponding to the total opening area of both air outlets 24, 25 is released into the atmosphere. The release operation in this case corresponds to the relief operation of the second relief valve mechanism 7, which is shown in the valve open state in FIG. 5 (C).

FIGS. 6 to 9 functionally show the structure of the dry cutout device 4 according to the fourth embodiment of the present invention, and FIGS. 6A and 6B are plan views and a vertical sectional front view in a non-operating state. FIGS. 7 (A) and 7 (B) are a plan view and a vertical sectional front view in the first stage operating state, and FIGS. 8 (A) and 8 (B) are a plan view and a vertical sectional front view in the second stage operating state. (A), (B) is a plan view and a vertical sectional front view of a third stage operation state. A fourth embodiment shown in FIG. 6 is a cylindrical casing 8, a first valve seat portion 11A, second valve seat portions 11B and 11C, which are sequentially provided in the casing 8 in three stages from the lower side, and each valve. The first valve 29, the second valve 30, and the third valve 31, which are spherical bodies provided in the seat portions 11A to 11C, are provided as element members to form a three-stage actuation type relief valve.

The casing 8 is divided into four chambers that are connected in the vertical direction by the three valve seat portions 11A to 11C, and the casing 8 is the first chamber that is the lowermost portion below the first valve seat portion 11A. S1 faces the opening at the lower end of the casing 8 and is connected to the gas pipe 1 via a branch pipe. The second chamber S2, which is formed between the first valve seat portion 11A and the second valve seat portion 11B, has the first air release opening to the upper end portion of the casing 8 through the passage 32 independently provided in the casing 8. It communicates with the mouth 35. The third chamber S3, which is formed between the second valve seat portion 11B and the third valve seat portion 11C, has the second air release opening to the upper end portion of the casing 8 through the passage 33 independently provided in the casing 8. It communicates with the mouth 36. The fourth chamber S4, which is formed above the third valve seat portion 11C, communicates with the third air outlet 37 that opens at the upper end of the casing 8 through the passage 34. As shown in FIG. 6A, the three air outlets 35 to 37 have the smallest opening area in the first air outlet 35 and the maximum in the third air outlet.

On the other hand, the three valves 29 to 31 are placed by closing the circular holes of the corresponding valve seats 11A to 11C, and are mounted on the guide wall portions provided in the valve seats 11A to 11C. It is provided so that it can be displaced in the vertical direction, and the valve seat portion is closed or floated according to the change of the gas (city gas) pressure in each of the chambers S1 to S3 immediately below so that each circular hole is opened. Operate.

At this time, in order to prevent the valves 29 to 31 from rising too much, a part of the structure of the valve seats 11A to 11C also serves as a stopper, and this set position is used when discharging to the atmosphere side. Position it so that it does not cause any problems. Further, the shape and dimensions of the stopper portion are preferably formed so that the surface pressure received on the spherical surface of each valve 29 to 31 can be varied. Since the weight of each valve 29 to 31 is related to the relief set pressure, it can be adjusted by its density or the amount of voids inside the sphere. Further, the sealing mechanism is performed on the contact surfaces of the valves 29 to 31 and the valve seat portions 11A to 11C. The displacement can be set based on the set pressure (working pressure) and the opening area of each air outlet 35-37.

The dry cutout 4 having such a structure has valves 29 to 31 as shown in FIG. 6B when the connected gas pipe 1 is kept at a normal pressure. Closes the valve seats 11A to 11C. When the internal pressure of the first chamber S1 is increased to the set pressure P1, the first valve 29 floats as shown in FIG. 7 (B), and the first chamber S 1 is divided into the first valve seat portion 11A and the second chamber S2. After passing through the passage 32, the first vent 35 communicates with the atmosphere, and a small amount of gas is released into the atmosphere. The operation at this time corresponds to the relief operation of the first relief valve mechanism 6.

When the pressures of the first chamber S1 and the second chamber S2 further rise and slightly exceed the set pressure P3, the second valve 30 floats and the second chamber S2 rises as shown in FIG. 8B. S2 communicates with the atmosphere through the second valve seat 11B, the third chamber S3, the passage 33 and the second air outlet 36. Therefore, a considerable amount of city gas is discharged through the first air outlet 35 and the second air outlet 36, so that the pressure rise is suppressed. The operation at this time corresponds to the relief operation of the second relief valve mechanism 7.

When the pressure in the first chamber S1 to the third chamber S3 further rises, the third valve 31 floats up as shown in FIG. 9B, and the third chamber S3 has a third valve seat portion 11C and a fourth valve seat portion 11C. It communicates with the atmosphere through the chamber S4, the passage 34 and the third air outlet 37. Therefore, a large amount of gas is discharged through the first air outlet 35 to the third air outlet 37, and the pressure increase is surely suppressed.

10 to 12 functionally show the structure of the dry cutout device 4 according to the fifth embodiment of the present invention. FIG. 10 is a non-operating state, FIG. 11 is a first stage operating state, and FIG. The second stage operating states are shown respectively. The fifth embodiment shown in these figures is similar to the fourth embodiment, and the corresponding parts bear the same reference numerals. What should be noted in this fifth embodiment is that the valve 29 and the valve 30 are interlocked at the stage shown in FIGS. 11 to 12. It is basically the same as the four examples. The operating state shown in FIG. 11 corresponds to the operation of the first relief valve mechanism 6, and the operating state shown in FIG. 12 corresponds to the operation of the second relief valve mechanism 7.

The fourth and fifth embodiments described above have a relatively simple structure and require no rubber member such as a diaphragm, so maintenance is easy and the discharge amount can be set easily. There are some advantages.

[0038]

[Effect of device]

 As described above, according to the present invention, when the pressure rise is mild, only a small amount of gas is discharged to reduce the loss and improve the safety. The pressure increase can be reliably prevented by discharging the gas. Furthermore, since the present invention is a dry cutout device, maintenance is labor-saving, and versatility can be enhanced by realizing low cost and compactness.

Further, according to the present invention, the first relief valve mechanism and the second relief valve mechanism prevent at least two pressure rises in the pipe, that is, a daily pressure increase phenomenon caused by a rise in ambient temperature and a decrease in atmospheric pressure. Since the relief operation is performed at the set pressure of the stage, it is possible to reliably suppress the abnormal rise in the pressure in the pipe while reducing the release of gas, so it is possible to avoid unforeseen situations such as accidental shutoff of the emergency shutoff valve and to improve reliability. High gas supply is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a pressure regulating / safety supply system for a gas pipe according to an embodiment of the present invention.

FIG. 2 is a pressure diagram for explaining an operation mode of a dry cutout 4 in the pressure regulation / safety supply system shown in FIG.

FIG. 3 is a schematic diagram functionally showing the structure of the dry cutout device 4 according to the first embodiment of the present invention in each operating state.

FIG. 4 is a schematic diagram functionally showing the structure of a dry cutout device 4 according to a second embodiment of the present invention in each operating state.

FIG. 5 is a schematic diagram in which the structure of a dry cutout device 4 according to a third embodiment of the present invention is functionally shown for each operating state.

FIG. 6 is a schematic view functionally showing a non-operating state of a dry cutout device 4 according to a fourth embodiment of the present invention.

FIG. 7 is a first embodiment of a dry cutout device 4 according to a fourth embodiment of the present invention.
It is a schematic diagram in which a stage operation state is functionally shown.

FIG. 8 is a second part of the dry cutout device 4 according to the fourth embodiment of the present invention.
It is a schematic diagram in which a stage operation state is functionally shown.

FIG. 9 is a third embodiment of the dry safety device 4 according to the fourth embodiment of the present invention.
It is a schematic diagram in which a stage operation state is functionally shown.

FIG. 10 is a schematic view functionally showing a non-operating state of a dry cutout device 4 according to a fifth embodiment of the present invention.

FIG. 11 is a schematic diagram functionally showing a first stage operating state of a dry cutout device 4 according to a fifth embodiment of the present invention.

FIG. 12 is a schematic diagram functionally showing a second stage operating state of a dry cutout device 4 according to a fifth embodiment of the present invention.

FIG. 13 is a schematic diagram of a conventional pressure regulation / safety supply system.

14 is a schematic diagram of a water-sealed cutout 5 in the pressure regulation / safety supply system shown in FIG.

[Explanation of symbols]

 1 Gas Pipe 2 Governor 3 Emergency Shutoff Valve (ESV) 4 Dry Safety Device 5 Water Seal Safety Device 6 First Relief Valve Mechanism 7 Second Relief Valve Mechanism 8 Casing 9 Valve Body 10 Valve Rod 11 Valve Seat 12 Diaphragm 13 Spring 14 Small Hole 15 Slit Hole 16 Diaphragm Chamber 17 Valve Seat 18 First Valve 19 Second Valve 24 First Air Outlet 25 Second Air Outlet

Claims (2)

[Scope of utility model registration request] 1. An emergency shut-off valve and a governor are connected in series, and are connected in the middle of a gas pipe downstream from the governor so as to be branched without using a liquid as a sealing material.
This is a multi-stage dry type safety device that operates at a set pressure higher than the set pressure, and operates at a low stage specified pressure equal to or lower than the preset pressure of the emergency shutoff valve, which is equivalent to the daily pressure increase. First relief valve mechanism that releases a small amount of gas to the atmosphere, and the first relief valve mechanism that operates at a high pressure higher than a predetermined high pressure that is equivalent to a warning pressure higher than the preset pressure of the emergency shutoff valve. And a second relief valve mechanism that releases a larger amount of the gas to the atmosphere than the amount of the dry safety device. 2. An emergency shut-off valve and a governor are connected in series, and are connected in the middle of a gas pipe branching downstream from the governor without using a liquid as a sealing material.
This is a multi-stage dry type safety device that operates at a set pressure of more than one stage, and operates at a low stage predetermined pressure that is lower than the preset pressure of the emergency shutoff valve and is equivalent to the daily pressure increase. First relief valve mechanism for releasing a small amount of gas to the atmosphere, and operated at a high pressure higher than a predetermined high pressure, which is lower than the set pressure of the emergency shutoff valve and higher than the low pressure specified above. And a second relief valve mechanism that releases a larger amount of the gas to the atmosphere than the amount discharged by the first relief valve mechanism.