JP6130480B1 - Thermally operated safety valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately determine the operating state of a thermally actuated safety valve from outside the safety valve. A main body 4 has high-pressure fluid passages 18, 24, 28 communicating with the outside, and a piston 30 can move in a small-diameter recess 26 in the main body 4. An O-ring 42 that can open and close the service passage 18 is provided. A soluble material 32 is fixed in contact with the piston 30 in the small-diameter recess 26. The soluble material 32 maintains the closed state of the passage 18 by the O-ring 42 in the solid state, melts as the temperature of the main body 4 rises, and passes through the branch passage 34 branched from the small-diameter recess 26 to the outside of the main body 4. The piston 30 is moved out and the O-ring 42 is separated from the passage 18 to open the passage 18. An indicator rod 44 provided on the surface of the piston 30 opposite to the O-ring 42 is provided in a portion of the main body 4 different from the passage 18 and the branch passage 34, and moves according to the movement of the piston 30 and the O-ring 42. [Selection] Figure 1

Description

  The present invention relates to a thermally operated safety valve that is attached to a high-pressure facility containing high-pressure fluid and discharges the high-pressure fluid to the outside of the high-pressure facility when the temperature rises. In particular, the operating state can be confirmed from the outside. About things.

  Conventionally, as the above-described safety valve, an operation state that can be confirmed from the outside is disclosed in Patent Document 1, for example. In the technique of Patent Document 1, the main body is hermetically attached to the high-pressure gas facility, and an opening is formed in the main body so as to communicate with the gas atmosphere in the gas facility. A closed piston housing hole is formed in the main body so as to communicate with the opening, and the piston is housed in the piston housing hole so as to slide along the peripheral wall of the piston housing hole. An external air communication hole is formed in the main body so as to open the piston housing hole to the outside, and the external air communication hole is opened and closed by the piston. A spring is disposed between the opening and the piston so as to exert a biasing force that separates the piston from the opening. In order to receive the urging force of the spring via the piston, the end of the piston housing hole is arranged so that the soluble material that dissolves when exposed to a predetermined temperature or higher is exposed to the gas atmosphere. A blocking plug is attached to the opening on the atmosphere side of the outside air communication hole.

  In this safety valve, at a temperature lower than a predetermined temperature, the soluble material receives the biasing force of the spring, and the piston closes the outside air communication hole. The piston is moved by the urging force, and the outside air communication hole is opened. At this time, the gas in the gas facility enters the outside air communication hole through the opening on the atmosphere side of the outside air communication hole and the piston housing hole, and the pressure causes the plug to be detached from the atmosphere side opening of the outside air communication hole, Is discharged into the open air.

Japanese Patent No. 4466193

  With this safety valve, it can be determined whether or not the safety valve has been operated by checking whether or not the obstruction stopper has been detached from the outside air communication hole. However, in this safety valve, the closure plug is attached to the external communication hole, and it is determined whether or not the safety valve is operating by the removal of the closure plug when gas passes through the external communication hole. The stopper does not directly represent the operation of the piston.For example, if the obstructing stopper has fallen from the outside air communication hole for some reason, it is mistaken that the safety valve is operating even though the outside air communication hole is not opened by the piston. Make a judgment. That is, it cannot be accurately determined from the outside of the safety valve whether or not the safety valve is operating, depending on whether or not the closing plug is removed.

  An object of the present invention is to provide a thermally activated safety valve whose operating state can be accurately determined from the outside.

In the safety valve of one aspect of the present invention, a high-pressure fluid passage communicating with the outside is formed in a main body mounted on a high-pressure fluid facility such as a pressure vessel or a high-pressure fluid passage, and a cylinder is provided in the main body. A piston is provided in the cylinder so as to be movable. A fluid blocking body capable of opening and closing the high-pressure fluid passage is provided on one surface side of the piston. As the fluid blocker, for example, a seal member that opens and closes the high-pressure fluid passage, such as an O-ring, can be used, and a valve body that can be seated and separated from a valve seat provided in the middle of the high-pressure fluid passage is used. can do. A fusible material is fixed in the cylinder in contact with the other surface of the piston. The soluble material maintains the closed state of the high-pressure fluid passage by the fluid blocker in the solid state, and dissolves as the temperature of the high-pressure fluid facility or the atmosphere of the high-pressure fluid facility increases. By fusible material is flowing out of the body through the branch passage provided in said main body and moved by the pressure before Symbol piston example high pressure fluid in the dissolved state, the fluid cutoff of the high-pressure fluid passage The closed state due to is the open state. In order to smoothly move the piston when the soluble material is melted, an urging means may be provided so as to face the soluble material with the piston interposed therebetween. Further, another soluble material is provided in the branch passage so as to prevent the soluble material dissolved in the solid state from flowing out . In this case, another soluble material starts to melt at a temperature higher than the temperature at which the soluble material dissolves, and when at least a part of the soluble material is separated from the main body, it is discharged together with the dissolved soluble material to the outside of the main body. An indicator rod is provided on the fusible material side of the piston, the indicator rod opens the rod passage provided on the fusible material side of the main body, and the fluid blocker opens the high pressure fluid passage. It moves according to the movement of the piston, and can be observed from the outside during the movement. The indicator rod can be integrally formed with the piston, or an indicator rod that is formed separately from the piston can be integrated with the piston.

  In the heat-actuated safety valve configured as described above, since the indicator rod provided on the piston having the fluid blocking body can be observed from the outside, the movement state of the fluid blocking body can be accurately detected from the outside. For example, even if the piston slightly moves to the fusible material side for some reason, and the high pressure fluid is released to the outside through the fluid blocker, there is leakage of the high pressure fluid. Can be directly observed, and the operating state of the thermally actuated safety valve can be confirmed accurately. Further, the indicator rod is provided on the piston opposite to the fluid blocker, and the indicator rod moves in a rod passage different from the high-pressure fluid passage and the branch passage. The fluid does not flow, and the rod portion only needs to be a dissolved soluble material seal.

  An end of the rod passage opposite to the piston may be opened, and the length of the indicator rod may be selected so that the indicator rod protrudes from the rod passage in the melted state. If comprised in this way, it can be easily recognized whether the safety valve is operating by whether the rod protrudes from the main body. Further, when the fusible material is in a solid state, the end of the indicator rod opposite to the piston is positioned at the opening of the rod passage, so that when the piston moves slightly, the indicator rod slightly Since it protrudes from the working passage, a slight movement state of the piston can be recognized.

  Alternatively, the end of the rod passage opposite to the piston may be opened, and the length of the indicator rod may be selected so as not to protrude from the rod passage when the soluble material is in the molten state. If comprised in this way, the position of the indicator rod can be known by observing the inside of the rod passage from the opening side of the rod passage, and the movement state of the piston can be recognized.

  A hole that penetrates the main body from a predetermined position of the rod passage and communicates with the outside may be formed. With this configuration, by observing the cylinder passage from this hole, it can be confirmed whether or not the piston is moving so that the indicator rod moves to at least a predetermined position. Whether or not the piston is moving so that the indicator rod moves to at least a predetermined position can be confirmed by inserting a confirmation tool and whether or not the tool contacts the indicator rod.

  As described above, according to the safety valve of the present invention, the operating state of the thermally actuated safety valve can be accurately determined from the outside.

It is a longitudinal cross-sectional view which shows the valve closing state and valve opening state of the safety valve of the reference example of this invention. It is a longitudinal cross-sectional view which shows the valve closing state and valve opening state of the safety valve of the 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the valve closing state of the safety valve of the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the valve closing state of the safety valve of the 3rd Embodiment of this invention.

A safety valve according to a reference example of the present invention is provided in a high-pressure facility, for example, a high-pressure hydrogen gas container 2 shown by a one-dot chain line in FIG. 1A. The high-pressure hydrogen gas container 2 contains a high-pressure fluid, for example, high-pressure hydrogen gas inside. Is housed in. When the temperature of the high-pressure hydrogen gas container 2 becomes equal to or higher than a predetermined temperature, the safety valve operates to discharge the high-pressure hydrogen gas in the high-pressure hydrogen gas container 2 to the outside.

  This safety valve has a main body 4. The main body 4 has a base portion 6, the base portion 6 is formed in a flat plate shape, for example, a disk shape, and has a male screw portion 8 formed in a cylindrical shape at one main surface, for example, the center of the lower surface, and its outer periphery. A male screw 10 is formed on the surface. The male screw 10 is screwed into a female screw portion 14 formed on the inner peripheral surface of the passage 12 formed to communicate with the high-pressure hydrogen gas container 2 to the outside.

  A substantially cylindrical passage 18, for example, is formed through the center of the end of the male screw portion 8 on the passage 12 side to the other main surface of the base portion 6, for example, the upper surface. The passage 18 is enlarged in diameter on the way from the passage 12 side to the base 6 to form a step.

  A cylindrical portion, for example, a cylindrical portion 20 is formed concentrically with the passage 18 on the upper surface of the base portion 6. The cylindrical portion 20 has a diameter smaller than that of the base portion 6, extends upward from the upper surface of the base portion 6, and has an upper end opened. The cylindrical portion 20 is covered with the body portion 22 of the main body 4 and screwed together. Note that an O-ring 23 for sealing is disposed between the outer peripheral surface of the cylindrical portion 20 and the body portion 22.

  The trunk portion 22 is also formed in a cylindrical shape, for example, a cylindrical shape, and its outer diameter is the same as the outer diameter of the base portion 6. Inside the trunk portion 22, a large-diameter recess 24 having a large diameter from the end on the base portion 6 side, that is, the lower end to the opposite side, that is, toward the upper end side, is somewhat higher than the upper end of the cylindrical portion 20. The small-diameter recess 26 having a smaller diameter than the large-diameter recess 24 is formed following the large-diameter recess 24. The upper end of the small-diameter recess 26 is closed. The large diameter recess 24 and the small diameter recess 26 are formed concentrically with the passage 18. The base 6 and the body 22 are both made of a material having good heat conduction, for example, metal.

  An opening 28 is formed in the vicinity of the boundary between the large diameter recess 24 and the small diameter recess 26 so that the large diameter recess 24 communicates with the outside. The passage 18 and the large-diameter recess 24 form a high-pressure fluid passage communicating with the outside through the opening 28.

  A piston 30 is disposed in the small-diameter recess 26 so as to be slidable in the vertical direction in the small-diameter recess 26. That is, the small diameter recess 26 functions as a cylinder. An O-ring 31 for sealing is provided around the piston 30. A soluble material 32 is disposed between the upper surface of the piston 30 and the upper end of the small-diameter recess 26 in a state where the lower surface of the piston 30 is located near the lower surface of the small-diameter recess 26. The fusible material 32 maintains an annular solid state when the temperature transmitted through the main body 4 is lower than a predetermined first predetermined temperature, and starts melting when the temperature exceeds the first predetermined temperature. When the temperature exceeds a second predetermined temperature higher than the temperature, it is completely dissolved and liquefied. In order to discharge the melted soluble material 32 to the outside from a part of the small-diameter recess 26 in which the soluble material 32 is accommodated, a branch passage 34 communicating with the outside is formed. Has been. Further, biasing means, for example, a coil spring 36 is disposed between the lower surface of the piston 30 and the upper surface of the base 6 inside the cylindrical portion 20, and the piston 30 is moved to the soluble material 32 side by the biasing force, for example, spring force. Is pressed. The pressure of the high-pressure hydrogen gas supplied through the passage 18 also presses the piston 30 toward the soluble material 32 side. Accordingly, when the soluble material 32 is maintained in a solid state, the soluble material 32 receives the spring force of the coil spring 36 and the pressure of the high-pressure hydrogen gas, so that the piston 30 is in the lowered state shown in FIG. maintain. However, when the soluble material 32 is melted and cannot receive the spring force of the coil spring 36, the piston 30 starts to rise due to the spring force and the pressure of the high-pressure hydrogen gas from the passage 12, and the piston 30 has a small diameter recess. It rises to a raised state in contact with the upper surface of the place 26. That is, the piston 30 is raised by the thickness of the soluble material 32. At this time, the dissolved soluble material 32 is discharged to the outside of the main body 4 through the branch passage 34.

  When the rod 38 extends downward from the center of the lower surface of the piston 30 through the center of the coil spring 36 and the soluble material 32 is in a solid state, the rod 38 enters the upper portion of the step in the passage 18. An O-ring support 40 is formed at the tip of the rod 38. The tip of the O-ring support 40 enters the lower portion of the passage 18 when the soluble material 32 is in a solid state. . On the upper side of the step portion of the passage 18, a fluid blocker, for example, a sealing O-ring 42 is attached in close contact with the upper portion of the step portion around the O-ring support body 40 to block the passage 18. . When the piston 30 is lifted as described above, the sealing O-ring 42 is also lifted to escape from the upper portion of the passage 18 and open the passage 18. Therefore, the inside of the high-pressure hydrogen gas container 2 communicates with the outside of the main body 4.

  An indicator rod 44 is provided at the center on the upper surface side of the piston 30 so as to extend upward. The indicator rod 44 is inserted into the indicator passage 46. The indicator passage 46 is formed in a straight line from the upper end of the small-diameter recess 26 to the upper surface of the trunk portion 22 concentrically with the passage 18, and the upper end of the indicator passage 46 opens at the upper surface of the trunk portion 22. The indicator rod 44 is inserted through the indicator passage 46 through the fusible material 32. A sealing O-ring 47 is provided in the middle of the indicator passage 46. The upper end of the indicator rod 44 is positioned at the upper end of the indicator passage 46 in the lowered state of the piston 30 where the O-ring 42 blocks the passage 18. When the piston 30 is raised, the upper end of the indicator rod 44 protrudes from the upper end of the indicator passage 46, and particularly when the piston 30 is in the raised state and the O-ring 42 completely opens the passage 18, the indicator The working rod 44 protrudes most as shown in FIG. The marker 48 is formed on the indicator rod 44 so that the indicator, for example, the lower end of the marker 48 is positioned at the upper end of the indicator passage 46 when the indicator rod 44 protrudes the most. Thus, when the O-ring 42 does not completely open the passage 18 but appears to rise, the indicator rod 42 protrudes from the indicator passage 46, while the marker 48 is in the indicator passage 46, It cannot be seen from the outside.

  In the safety valve configured as described above, in the lowered state of the piston 30 shown in FIG. 1A, the O-ring 42 blocks the passage 18, and the pressure of the high-pressure hydrogen gas is applied to the O-ring 42. The pressure of the high-pressure hydrogen gas and the spring force of the coil spring 36 are applied to try to raise the piston 30, but the soluble material 32 in the solid state receives the pressure and the spring force and is driven by the O-ring 42. The blocking state of the passage 18 continues, and the high-pressure hydrogen gas in the high-pressure hydrogen gas container 2 is not discharged to the outside of the main body 4. At this time, the indicator rod 44 does not protrude from the upper end of the trunk portion 22, and it can be seen from the outside that this safety valve is not operating.

  When the temperature of the high-pressure hydrogen gas container 2 itself or the ambient temperature of the high-pressure hydrogen gas container 2 rises due to a fire, for example, and the temperature of the main body 4 rises, the soluble material 32 is dissolved as described above, and the high-pressure hydrogen gas The piston 30 is raised by the pressure and the spring force of the coil spring 36, and the meltable soluble material 32 is discharged from the branch passage 34 to the outside of the trunk portion 22 as shown in FIG. Then, the passage 18 is opened, and the high-pressure hydrogen gas in the high-pressure hydrogen gas container 2 is discharged to the outside of the main body 4.

  When the passage 18 is opened, the tip of the indicator rod 44 protrudes upward from the upper end of the body 22 as shown in FIG. 1B, and the safety valve operates at a glance. I know that. That is, the indicator rod 44 is mechanically linked to the operation of the O-ring 42 to represent the operation of the safety valve. In particular, when the marker 48 is visible, it can be seen that the piston 30 has slid to the raised position and the O-ring 42 has completely opened the passage 18. Furthermore, since the indicator rod 44 is coupled to the piston 30 and directly represents the moving state of the O-ring 42, the operating state of the safety valve can be confirmed accurately. For example, when the piston 30 is slightly raised even though the soluble material 32 is not dissolved due to a change such as creep of the soluble material 32, the marker 48 is not visible, but the tip of the indicator rod 44 is Since it protrudes slightly from the upper end of the part 22, it turns out that the piston 30 has moved slightly. Moreover, since the indicator rod 44 is formed on the upper surface side of the piston 30 and is separated from the large-diameter recess 24 through which the high-pressure hydrogen gas passes, a mechanism for determining whether the safety valve has operated. And the high-pressure fluid passage through which the high-pressure hydrogen gas flows when the safety valve is operated, the opening 28 is connected to the pipe using an appropriate connector, and the atmosphere is separated from the safety valve in the atmosphere. Even if high-pressure hydrogen gas is released, the indicator does not move in the piping as in the blocking plug of the prior art document, and it is possible to accurately determine whether or not the safety valve has been operated. There will be no clogging. In addition, since the mechanism for determining whether the safety valve is operated as described above and the high-pressure fluid passage through which the high-pressure hydrogen gas flows when the safety valve is operated are separated and independent, the indicator rod 44 and the indicator passage 46 are separated. It is not necessary to consider that high-pressure hydrogen gas leaks through the piston 30, and the high-pressure hydrogen gas is sealed by the piston 30 and the O-ring 31. Therefore, the indicator rod 44 and the indicator passage 46 need not consider gas leakage. No.

  In this way, if it is possible to determine whether or not the safety valve is operating from the outside without touching the safety valve, the safety valve operates when an accident such as a fire occurs in the high-pressure hydrogen gas container 2 unfortunately. It is possible to determine whether or not the operator has touched the safety valve, and is effective when, for example, it is dangerous for the worker to touch the high-pressure hydrogen gas container 2.

The safety valve of the first embodiment of the present invention is shown in FIGS. 2 (a) and 2 (b). In the safety valve of the first embodiment, the opening 28 is formed in the port 28a in order to facilitate connection to a pipe for discharging outside air at a remote position. Further, the end of the branch passage 34 is enlarged, and a separator, for example, a ball 50 is disposed so as to close the non-expanded portion 34b in the enlarged portion 34a. The ball 50 is made of rubber, for example, and has a diameter larger than that of the non-expanded portion 34b. In order to hold the ball 50, an annular ball holding body 52 is disposed inside the enlarged portion 34a. The ball holding body 52 has a through hole 54 that penetrates in the length direction of the non-enlarged portion 34b and holds the ball 50 in the center thereof, and the through hole 54 is concentric with the non-enlarged portion 34b. The ball holder 52 is disposed.

  The ball holder 52 is attached to the outside of the main body 4 of the enlarged portion 34a by an annular fixture 56 disposed on the outer surface side thereof. A part of the outer end of the fixture 56 protrudes outward from the body portion 22. The ball holder 52 is made of resin, for example, and the fixture 56 is made of metal, for example.

  A frustoconical through hole 60 whose diameter is gradually reduced from the ball holding body 52 side of the fixture 56 to the outer side of the fixture 56 is formed concentrically with the non-expanded portion 34b. Another soluble material 62 is attached to the through-hole 60, and the outer surface is exposed to the outside of the main body 4. The other soluble material 62 prevents the dissolved soluble material 32 and the ball 50 from being discharged to the outside of the main body 4 in a solid state. The other soluble material 62 starts to dissolve at a third predetermined temperature higher than the second predetermined temperature at which the soluble material 32 completely dissolves, and is a fourth predetermined temperature somewhat higher than the third predetermined temperature. Thus, the outer peripheral surface of another fusible material 62 is melted away from the peripheral surface of the through hole 60 of the fixture 56. Accordingly, when a force is applied from the completely dissolved soluble material 32 and the ball 50, another soluble material 62 jumps out of the fixture 56 to the outside.

Since the other configuration is the same as the configuration of the safety valve of the reference example, the same reference numeral is given to the same portion, and the description thereof is omitted.

  In this safety valve, at a temperature lower than the first predetermined temperature at which the soluble material 32 starts to melt, the pressure of the high-pressure hydrogen gas in the high-pressure hydrogen gas container 2 is applied to the O-ring 42, and this pressure is applied to the piston 30. The spring force of the coil spring 36 is also applied to the piston 30. However, since the fusible material 32 is in a solid state, the O-ring 42 maintains the blocking state of the passage 18 as shown in FIG.

  The temperature of the high-pressure hydrogen gas container 2 rises due to, for example, a fire or the like, and is higher than a second predetermined temperature at which the soluble material 32 is melted, and lower than a temperature at which another soluble material 62 starts to melt. When this happens, the soluble material 32 is in a dissolved state. At this time, the pressure of the high-pressure hydrogen gas also rises, and this high-pressure hydrogen gas pressure and the spring force of the coil spring 36 are separated from each other via the piston 30, the dissolved soluble material 32, the non-expanded portion 34 b of the branch passage 34, and the ball 50. Applied to the soluble material 62. However, since the temperature is equal to or lower than the third predetermined temperature at which another soluble material 62 starts to dissolve, the other soluble material 62 maintains a solid state and does not flow out to the outside, and the valve body 40 blocks the passage 18. The state is maintained.

  When the temperature of the safety valve reaches the third predetermined temperature, the peripheral surface of another soluble material 62 starts to melt, and when the temperature further rises to a fourth predetermined temperature or more, the other soluble material 62 penetrates. The other soluble material 62 cannot prevent the high-pressure hydrogen gas pressure applied to the melted soluble material 32 via the piston 30 and the spring force of the coil spring 36 from being in non-contact with the main surface of the hole 60, and the melted state. The other soluble material 62 and the ball 50 are discharged to the outside together with the soluble material 32 and the ball 50, the piston 30 is raised, the O-ring 42 opens the passage 18 as shown in FIG. 18. It is discharged into the atmosphere at a position away from the safety valve via the large diameter recess 24 and the port 28a. At this time, the indicator rod 44 is also lifted, protrudes from the upper end of the body portion 22 of the main body 4, and the marker 48 is visible, so that it can be confirmed from the outside that the safety valve is operating. Further, although the marker 48 cannot be seen, when the indicator rod 44 protrudes from the upper end of the body portion 22, it can be seen that the O-ring 42 is raised due to, for example, the creep of the soluble material 32.

The safety valve of the second embodiment is shown in FIG. This safety valve is the same as the safety valve of the first embodiment, but when the indicator rod 44 is shortened so that the O-ring 42 opens the passage 18 and the O-ring 42 is disengaged from the upper portion of the passage 18, the indicator rod 44 The length of the indicator rod 44 is selected so that the upper end of the indicator is positioned at the upper end of the indicator passage 46. Since the other configuration is the same as that of the safety valve of the first embodiment, the same parts are denoted by the same reference numerals and description thereof is omitted.

  The upper end of the indicator passage 46 is closed by a filter 64 so as to allow ventilation. Therefore, when determining whether or not the safety valve is operating, when the filter 64 is removed and the inside of the indicator passage 46 is viewed, the upper end of the indicator rod 44 is positioned at the upper end of the indicator passage 46. When the upper end of the indicator rod 44 is located at a position where the safety valve is operated and the passage 18 is opened and the upper end of the indicator passage 46 is not reached, the position where the passage 18 is completely opened. It can be seen that the O-ring 42 has not moved. If the filter 64 is made of a transparent material, it is not necessary to remove the filter 64.

A safety valve of the third embodiment is shown in FIG. This safety valve is designed to confirm whether or not the safety valve is operating from the side of the body 22, and an observation window passage 66 opened to the side of the body 22 in the middle of the indicator passage 46. The indicator rod 44 is located at a position where the upper end of the indicator rod 44 corresponds to the window passage 66 when the O-ring 42 opens the passage 18 and the O-ring 42 is disengaged from the upper portion of the passage 18. Thus, the length of the indicator rod 44 is selected. In order to facilitate observation from the window passage 66, the marker 48 is provided on the upper end of the indicator rod 44. Since other configurations are the same as those of the safety valve of the second embodiment, the same parts are denoted by the same reference numerals, and the description thereof is omitted. Note that it is also possible to determine whether or not the safety valve is operating by inserting a rod-shaped tool from the outside of the window passage 66 and determining whether or not the tip of the tool contacts the indicator rod 44. When the insertion of such a tool is not considered, the window passage 66 can be filled with a transparent resin.

In the reference example and the first embodiment, only one marker 48 is provided. However, the marker is moved downward along the length direction of the indicator rod 44 at a predetermined distance from the upper end of the indicator rod. It is also possible to provide it. In this case, the operation stop position of the piston 30 can be determined based on how many markers protrude from the upper end of the body portion 22. Similarly, in the third embodiment, a plurality of markers are provided on the indicator rod 44, and the operation stop position of the piston 30 can be determined based on which marker is visible from the window passage 66. In the case of the second embodiment, if the marker is provided on the inner peripheral surface of the indicator passage 46 at predetermined distances along the length direction, the operation stop position of the piston 30 is similarly determined. be able to. Also in the reference example , by adjusting the length of the indicator rod 44 in the same manner as the safety valve of the second and third embodiments, the indicator passage is formed from the upper portion of the trunk portion 22 as in the second embodiment. The operating state of the safety valve can be determined by looking at 46 or by looking at the indicator passage 46 from the window passage provided on the side of the body portion 22 as in the third embodiment. In each of the above embodiments, the indicator rod 44 is formed integrally with the piston 30. However, the indicator rod 44 may be formed separately from the piston 30, and the indicator rod 44 may be attached to the upper surface of the piston 30. .

  In the safety valve of each embodiment described above, the coil spring 36 is provided. However, for example, when the gas pressure in the high-pressure hydrogen gas container 2 is high, the coil spring 36 is not necessary. Although the safety valve of each of the above embodiments is used as a safety valve for high-pressure hydrogen gas, it can be used for other gases or liquids. As the soluble material 32 used in each embodiment, a material that starts melting at a first predetermined temperature and enters a dissolved state at a second predetermined temperature is used. However, the first and second predetermined temperatures are the same eutectic. Alloys can also be used. Similarly, another soluble material 62 used in the second to fourth embodiments also starts to melt at the third predetermined temperature, and the outer peripheral surface of the other soluble material 62 is attached to the fixture 56 at the fourth predetermined temperature. Although the thing away from the surrounding surface of this through-hole 60 was used, the 3rd and 4th predetermined temperature can also use the same eutectic alloy. In each of the above embodiments, the safety valve is provided in the high-pressure hydrogen gas container. However, the safety valve is not limited to this, and may be provided in, for example, a high-pressure fluid path.

4 Body 26 Small-diameter recess (cylinder)
30 piston 32 soluble material 42 O-ring (fluid blocker)
44 Indicator rod (indicator)

Claims (1)

A high-pressure fluid passage formed in a main body attached to the high-pressure fluid facility and communicating with the outside;
A cylinder provided in the main body;
A piston provided in the cylinder so as to be movable in the cylinder;
A fluid blocking body provided on one surface side of the piston so as to be able to open and close the high-pressure fluid passage;
The piston is fixed in the cylinder in contact with the other surface of the piston, the closed state of the high-pressure fluid passage by the fluid blocker is maintained in a solid state, and the temperature of the atmosphere of the high-pressure fluid facility or the high-pressure fluid facility is increased. As a result, the piston moves by flowing out of the main body through a branch passage provided in the main body, and the closed state of the high-pressure fluid passage by the fluid blocker can be opened. With the melt,
The rod passage provided on the fusible material side of the piston and formed on the fusible material side of the main body moves in accordance with the movement of the piston in which the fluid blocking body opens the high pressure fluid passage, An indicator rod that can be observed from the outside of the main body during movement of the piston;
And in the solid state in the branch passage, another soluble material is provided so as to prevent outflow of the dissolved soluble material to the outside, and the other soluble material is higher than a temperature at which the soluble material is dissolved. A heat-actuated safety valve that starts melting at a temperature and is discharged to the outside of the main body together with the dissolved soluble material when at least a part of the branch passage leaves .

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