Tank shutoff valve

Abstract

To provide a tank shutoff valve that can prevent the leakage of liquid in a tank with a low-cost structure even if the tank becomes submerged in water due to flooding or the like, the tank floats or moves, and the piping is damaged. [Solution] This shutoff valve shuts off a flow path of a pipe 11 provided in a tank that stores liquid M. The shutoff valve includes a pressure detection chamber that is partially open to the atmosphere, and includes a water detection unit 20 that detects flooding of the tank based on a change in pressure caused by the inflow of water W from the outside into the pressure detection chamber and the outflow of gas E from the pressure detection chamber to the atmosphere due to the inflow of water W, and a shutoff unit 30 that operates based on the flooding detected by the water detection unit 20 and shuts off a flow path 43 through which liquid M stored in the tank flows.

Description

[Technical field]

[0001] The present invention relates to a tank shutoff valve that prevents liquid stored in a tank from leaking out in the event of a flood. [Background technology]

[0002] Conventionally, tanks for storing liquids, such as oil tanks for replenishing fuel for fishing boats and other vessels, have been installed in coastal areas such as ports (see, for example, Patent Documents 1 and 2). Such tanks are at risk of being damaged by flood damage such as tsunamis. Therefore, if the piping of a tank installed in a coastal area is damaged by flood damage such as a tsunami, there is a problem that the liquid stored inside the tank will leak out, and in order to prevent such leakage, a shutoff valve or the like is provided in the piping. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-149449 A [Patent Document 2] JP 2015-227182 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, electric or pneumatic remote shutoff valves have been installed in piping near tanks. However, these electric and pneumatic shutoff valves are explosion-proof, and the costs for the valve body and the electrical and pneumatic equipment are high, so there is room for improvement in this regard.

[0005] In view of the above circumstances, an object of the present invention is to provide a tank shut-off valve that can prevent the leakage of liquid within a tank with a low-cost structure, even if the tank becomes submerged in water due to flooding or the like, the tank floats or moves, and the piping is damaged. [Means for solving the problem]

[0006] One aspect of the present invention is a tank shutoff valve that shuts off a flow path of a pipe provided in a tank that stores liquid, the valve comprising: a pressure detection chamber that is partially open to the atmosphere; a water detection unit that detects flooding of the tank based on a change in pressure caused by an inflow of water from the outside into the pressure detection chamber and an outflow of gas from the pressure detection chamber to the atmosphere due to the inflow of water; and a shutoff unit that operates based on the flooding detected by the water detection unit and shuts off the flow path through which the liquid stored in the tank flows. The blocking unit is movable between an open position where the flow path is opened and a closed position where the flow path is closed, and is biased toward the closed position. A locking mechanism is provided to lock the blocking unit in the open position. The locking mechanism is provided with a locking operation unit and a locking operation unit that transmits a change in water pressure detected by the water detection unit to the locking operation unit. The locking operation unit is operated by the change in water pressure detected by the water detection unit to operate the locking operation unit, thereby unlocking the locking mechanism and moving the blocking unit to the closed position. , a tank shutoff valve.

[0007] According to the present invention, flooding of the tank, the tank shutoff valve, and its piping can be detected by a mechanical configuration, not an electrical configuration, in that the water detection unit detects the flooding of the tank, the tank shutoff valve, and its piping by the pressure change caused by the inflow of water and the outflow of gas into the pressure detection chamber. Then, the shutoff unit can be operated to shut off the flow path by the detection of flooding by the water detection unit. Therefore, in the present invention, the tank shutoff valve itself detects the water pressure in the pressure detection chamber at this time when the water level rises due to flood damage such as a tsunami, causing water to flow into the pressure detection chamber, and operates by detecting this water pressure. Therefore, electric and pneumatic equipment as in the past is not required, and there is no need to make these equipment explosion-proof, so the cost of the equipment can be reduced. In this way, in the present invention, even if the tank, the tank shutoff valve, and its piping are submerged in water due to flood damage, the outflow of liquid in the tank can be prevented by a low-cost structure.

[0008] In the present invention, it is preferable that the pressure detection chamber has an inlet that is open to the atmosphere and through which water flows in from the outside, and an outlet that is open to the atmosphere and through which gas flows out, which is provided above the inlet.

[0009] According to the present invention, when a flood such as a tsunami occurs, water flows into the pressure detection chamber from the inlet, and the gas in the pressure detection chamber can be discharged to the atmosphere from the outlet located above the inlet. Therefore, since water accumulates in the pressure detection chamber when a flood occurs, it is possible to detect flooding of the tank, the tank shutoff valve, and its piping by detecting the pressure change caused by the water flowing into the pressure detection chamber.

[0010] The present invention may also be characterized in that the pressure detection chamber has an inlet that is open to the atmosphere and through which water flows in from the outside, an outlet that is open to the atmosphere and through which gas flows out of the pressure detection chamber, and a diaphragm that separates a first space on the inlet side and a second space on the outlet side, and the diaphragm detects the differential pressure between the first space and the second space.

[0011] According to the present invention, when a flood such as a tsunami occurs and the water level rises, water flows into the first space of the pressure detection chamber from the inlet, and gas in the second space of the pressure detection chamber can be discharged to the atmosphere from the outlet located above the inlet. That is, the water pressure caused by the water flowing into the first space during a flood causes the diaphragm separating the first space and the second space to be pushed toward the second space, causing gas in the second space to be discharged from the outlet. The pressure difference between the first space and the second space can be detected from the amount of displacement of the diaphragm at this time, and thus flooding of the tank, the tank shutoff valve, and its piping can be detected.

[0012] In the present invention, the outlet may include a check valve for preventing inflow of gas or liquid from the outside.

[0013] According to the present invention, since the check valve is provided at the outlet, the gas in the pressure detection chamber can be reliably discharged to the outside, and gas or liquid from the outside can be prevented from flowing into the pressure detection chamber from the outlet. In other words, since only water flows into the pressure detection chamber from the inlet, only the pressure change caused by the water flowing into the pressure detection chamber can be accurately detected.

[0014] The present invention may also be characterized in that it further includes a hood portion formed to cover the water detection portion and prevent water from entering the pressure detection chamber when precipitation from above, while allowing water to flood the pressure detection chamber when water flows in from below.

[0015] According to the present invention, since a hood portion that covers the water detection portion is provided, it is possible to prevent the pressure detection chamber from being flooded by rainwater falling from above, and thus prevent malfunction. Furthermore, by providing a hood portion, water that flows in from below can be filled into the pressure detection chamber without being allowed to flow out to the outside. As a result, only water flows into the pressure detection chamber from the inlet, and therefore only pressure changes caused by water flowing into the pressure detection chamber can be accurately detected. Effect of the Invention

[0016] The tank shut-off valve of the present invention can prevent the leakage of liquid inside the tank with a low-cost structure, even if the tank becomes submerged in water due to flooding or the like, the tank floats or moves, or the piping is damaged. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a side view showing a configuration of a tank equipped with a shutoff valve according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of a shutoff valve, illustrating a non-shutoff state. [Diagram 3] FIG. 2 is a cross-sectional view showing the configuration of a shutoff valve, illustrating a shutoff state. [Figure 4] FIG. 4 is a diagram showing a state before water flows into a pressure detection chamber. [Diagram 5] 13A and 13B are diagrams illustrating a state after water has flowed into the pressure detection chamber. [Figure 6] FIG. 1 is a vertical cross-sectional view showing a shutoff valve having a filter and a strainer at the inlet. [Figure 7] FIG. 11 is a vertical cross-sectional view showing a shutoff valve having an air vent hole at the outlet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a tank shutoff valve according to an embodiment of the present invention will be described with reference to the drawings.

[0019] FIG. 1 is a side view showing the configuration of a tank 10 equipped with a shutoff valve 1 according to an embodiment. The tank shutoff valve (hereinafter, shutoff valve 1) of the embodiment shown in Fig. 1 shuts off the flow path of a pipe 11 provided in a tank 10 that stores liquid M. The shutoff valve 1 is a mechanical valve intended for tanks 10 installed in areas (coastal areas, etc.) that may be flooded with water due to various flood disasters such as tsunamis, high tides, typhoons, heavy rains, the collapse of dams or levees, and overflows, and prevents leakage of liquid M stored in the tank 10 even if the tank is flooded with water and the pipe 11 is damaged during a flood disaster. Here, Fig. 1 shows the state when a tsunami occurs.

[0020] As shown in FIG. 1, the tank 10 of this embodiment is, for example, a cylindrical oil tank. The tank 10 stores liquid M, which may be, for example, fuel for ships such as fishing boats, hazardous materials such as gasoline and diesel, or chemicals. The tank 10 is installed on a base 12 provided on the ground. The tank 10 and the base 12 are fixed to each other using, for example, anchor bolts and nuts. The fixing means between the tank 10 and the base 12 may be reinforced to integrate the tank 10 and the base 12 using FRP or the like to prevent leakage. Alternatively, the tank 10 and the base 12 may not be fixed to each other.

[0021] A pipe 11 is provided below the tank 10. A liquid M such as fuel stored inside the tank 10 flows through the pipe 11. The pipe 11 supplies fuel to a ship or the like. One end of the pipe 11 is connected to the tank 10, and the other end is connected to a nozzle or the like for supplying fuel to the ship or the like. A manual gate valve 13 for blocking the flow path of the pipe 11 is provided in the middle of the pipe 11. The flow path of the pipe 11 is normally opened by the gate valve 13. A shutoff valve 1 for the tank 10 (tank shutoff valve) is provided downstream of the gate valve 13. The shutoff valve 1 is provided in the middle of the pipe 11 that extends laterally in this embodiment. The shutoff valve 1 automatically shuts off the flow path of the pipe 11 when flooded. The shutoff valve 1 may move together with the tank 10 and the pipe 11 in the unlikely event that the tank 10 is washed away.

[0022] Fig. 2 is a cross-sectional view showing the configuration of shutoff valve 1, illustrating the non-shutoff state, and Fig. 3 is a cross-sectional view showing the configuration of shutoff valve 1, illustrating the shutoff state. 2 and 3, the shutoff valve 1 includes a water detection unit 20 that detects flooding of the tank 10, a shutoff unit 30 that shuts off a flow path 43 connected to the piping 11, and a hood unit 50 formed to cover the water detection unit 20. The shutoff valve 1 is installed in a horizontal position such that the axial direction of the internal flow path 43 is approximately parallel to the piping 11.

[0023] The shutoff unit 30 is provided in a valve box 40 having a flow path 43 through which the liquid stored in the tank 10 flows. The valve box 40 includes a first housing 41 to which the water detection unit 20 is attached, and a second housing 42 connected to the first housing 41 and to the piping 11. The first housing 41 is located above the second housing 42 when the shutoff valve 1 is installed. The water detection unit 20 is located on a side surface of the first housing 41.

[0024] 1, the flow path 43 has an inlet portion 431 on the left side of the page, an outlet portion 432 on the right side of the page, and a central communication portion 433 that is provided in the center of the flow path 43 and connects a downstream portion of the inlet portion 431 and an upstream portion of the outlet portion 432. Water W in the pipe 11 passing through the flow path 43 of the shutoff valve 1 flows from left to right. That is, the water W in the upstream pipe 11 flows in from the inlet portion 431, passes through the central communication portion 433, and flows from the outlet portion 432 to the downstream pipe 11.

[0025] The shutoff unit 30 operates based on flooding detected by the water detection unit 20. The shutoff unit 30 includes a valve body support shaft 31 that moves back and forth in the vertical direction based on flooding detected by the water detection unit 20, a housing portion 32 that houses the valve body support shaft 31, and a valve body 33 that shuts off the flow path 43 by the reciprocating movement of the valve body support shaft 31.

[0026] The valve element 33 is fixed to one end (here, the lower end) of the valve element support shaft 31. That is, the valve element 33 moves up and down together with the up and down reciprocating movement of the valve element support shaft 31. The valve element support shaft 31 is provided with a locking mechanism 34 that operates in conjunction with a coil spring 61 of the water detection unit 20. The valve element support shaft 31 is in a raised position (see FIG. 2) when the locking mechanism 34 is locked, and is in a lowered position (see FIG. 3) when the locking mechanism 34 is unlocked. The valve element 33 supported by the valve element support shaft 31 opens the flow path 43 when the valve element support shaft 31 is in the raised position (locking mechanism 34 is in the locked position), and closes the flow path 43 when the valve element support shaft 31 is in the lowered position (locking mechanism 34 is in the unlocked position).

[0027] The valve element 33 is provided in the flow path 43 so as to be vertically movable. The valve element 33 is provided so as to be openable and closable so as to close a central communication section 433 of the flow path 43. A valve seat 433a against which the valve element 33 can be opened and closed is provided on the outer circumferential edge of the opening of the central communication section 433 with the inlet section 431. The outer diameter of the lower end of the valve element 33 is larger than the inner diameter of the opening of the central communication section 433. The valve element 33 closes the central communication section 433 by being pressed against the valve seat 433a from above.

[0028] The lock mechanism 34 includes a biasing member (not shown) that biases the valve body 33 together with the valve body support shaft 31 in a direction to press the valve body 33 against the valve seat 433a. The biasing member is supported at one end within the accommodation portion 32, and is incorporated so as to bias the valve body support shaft 31 and the valve body 33 at the other end in a direction to press the valve body 33 against the valve seat 433a. The lock mechanism 34 locks the valve body 33 in a state (open position P1) in which the valve body 33 is separated from the valve seat 433a against the biasing force of the biasing member as shown in Fig. 2, and releases the lock in a state (closed position P2) in which the valve body 33 is abutted against the valve seat 433a via the lock operation piece 342 when the coil spring 61 of the water detection unit 20 is pressed as shown in Fig. 3.

[0029] The lock mechanism 34 has a lock operation part 341 and a lock operation piece 342 that operates the lock operation part 341. The lock operation piece 342 moves forward and backward in the axial direction X (described later) in response to the detection operation of the water detection part 20. The lock operation part 341 lifts the valve body support shaft 31 and the valve body 33 against the biasing force of the biasing member by operation of the lock operation piece 342, and locks the valve body 33 at an open position P1 in a state in which the valve body 33 is separated from the valve seat 433a. The lock operation part 341 also releases the lock at a closed position P2 in a state in which the valve body support shaft 31 and the valve body 33 are lowered by the biasing force of the biasing member by operation of the lock operation piece 342, and the valve body 33 is brought into contact with the valve seat 433a.

[0030] Here, in the water detection unit 20 and the hood unit 50, the diaphragm axis O passes through the center of the diaphragm 24, which will be described later, in a plan view. The direction parallel to the diaphragm axis O is called the axial direction X. In the axial direction X, the side of the valve disc support shaft 31 is called the inner side X1, and the opposite side is called the outer side X2. Moreover, the direction perpendicular to the diaphragm axis O when viewed from the axial direction is called the radial direction.

[0031] 1, the hood portion 50 is formed so as to cover the water detection portion 20, and prevents water from entering the pressure detection chamber 21 when rain falls from above, while allowing water to enter the pressure detection chamber 21 when water W flows in from the inlet 22 below. The hood portion 50 is divided into two in the axial direction X. The pair of divided hood portions 50 are fixed together while sandwiching the outer circumferential edge 24a of the diaphragm 24, which will be described later, over the entire circumference.

[0032] The hood section 50 is formed in a substantially cylindrical shape coaxial with the diaphragm axis O. The hood section 50 includes a first hood body 51 forming a pressure detection chamber 21 that houses the water detection section 20, and a second hood body 52 that houses a coil spring 61. The first hood body 51 is fixed to the first housing 41. The second hood body 52 is provided on the opposite side (outside X2) of the first housing 41 across the first hood body 51. The first hood body 51 has a central tube 51A located at the center in the axial direction X and supporting the diaphragm 24, an inner plate 51B located on the first housing 41 side of the central tube 51A, and an outer plate 51C located on the second hood body 52 side of the central tube 51A. In the hood section 50, the inner diameter of the central tube 51A is the largest.

[0033] The second hood body 52 is cylindrical and arranged coaxially with the diaphragm axis O. The inner end of the second hood body 52 is an open end and communicates with the inside of the first hood body 51 (pressure detection chamber 21). The outer end of the second hood body 52 is closed by a lid body 53. A coil spring 61 arranged coaxially with the diaphragm axis O is housed inside the second hood body 52. ​​The inner diameter of the second hood body 52 is larger than the outer diameter of the coil spring 61. In the second hood body 52, a reaction wall 54 supporting one end 61a of the coil spring 61 is provided on the inner side X1 of the lid body 53.

[0034] Fig. 4 is a diagram showing a state before water W flows into the pressure detection chamber 21. Fig. 5 is a diagram showing a state after water W flows into the pressure detection chamber 21. 4 and 5, the water detection unit 20 includes a pressure detection chamber 21 that is partially open to the atmosphere. The water detection unit 20 detects flooding of the tank 10 based on a change in pressure caused by the inflow of water W from the outside into the pressure detection chamber 21 and the outflow of gas E from the pressure detection chamber 21 to the atmosphere accompanying the inflow of water W.

[0035] The pressure detection chamber 21 has an inlet 22 and an outlet 23. The inlet 22 is provided below the pressure detection chamber 21 and is open to the atmosphere, through which water W flows in from the outside. The inlet 22 is located on one of the left and right sides of the hood portion 50 when viewed from the axial direction X (the far side of the paper in Figs. 3, 4, and 5), and opens downward. The inlet 22 is formed in an umbrella shape that increases in diameter downward. By forming the inlet 22 in an umbrella shape in this way, the inflow of the water W is stabilized, and malfunctions in the detection of the water W can be prevented. The outlet 23 is provided above the inlet 22 and is open to the atmosphere, through which the gas E flows out of the pressure detection chamber 21. The outlet 23 opens upward. It is desirable to provide multiple inlets 22 so that water W can flow in against tsunamis coming from any direction, i.e., so that the inflow of water W is not restricted by valves or nearby structures or vortexes.

[0036] The pressure detection chamber 21 has a diaphragm 24 that separates the first space 21A on the inlet 22 side from the second space 21B on the outlet 23 side in a horizontal direction (axial direction X) perpendicular to the up-down direction. The first space 21A is located on the first housing 41 side. The second space 21B is located on the opposite side to the first space 21A across the diaphragm 24. The inlet 22 communicates with the first space 21A and does not communicate with the second space 21B. The outlet 23 communicates with the second space 21B and does not communicate with the first space 21A. By providing the outlet 23, when water W enters the first space 21A from the inlet 22, the gas E can be discharged upward to prevent air from accumulating in the first space 21A.

[0037] The diaphragm 24 is disposed within the pressure detection chamber 21 so as to divide the pressure detection chamber 21 in the horizontal direction, and detects the differential pressure between the first space 21A and the second space 21B. The diaphragm 24 is fixed in a state in which the outer peripheral edge 24a is sandwiched between a pair of divided hood portions, which will be described later. The diaphragm 24 is formed of an elastic member, and divides the first space 21A and the second space 21B in a liquid-tight manner.

[0038] The central portion of the diaphragm 24 in plan view is supported by being sandwiched between a pair of support plates 62A and 62B. The first support plate 62A supports the diaphragm 24 from the first space 21A side. The second support plate 62B supports the diaphragm 24 from the second space 21B side. One end 342a of a lock operation piece 342 extending coaxially with the diaphragm axis O is fixed to the first support plate 62A. The lock operation piece 342 penetrates the hood portion 50 and the pressure detection chamber 21 in a liquid-tight manner, and the other end 342b is connected to the lock operation portion 341 in the first housing 41 (see FIG. 2). The diaphragm 24 can move forward and backward in the axial direction X by the action of the water W flowing into the first space 21A and the spring force of the coil spring 61.

[0039] The outer diameter of the second support plate 62B is smaller than the inner diameter of the central cylinder 51A of the hood portion 50. The other end 61b of the coil spring 61 presses against the outer surface 62a of the second support plate 62B from the outer side X2. That is, the diaphragm 24 supported by the second support plate 62B is maintained in a state in which it is biased toward the inner side X1 by the biasing force of the coil spring 61. When water W flows into the first space 21A, the diaphragm 24 is displaced toward the outer side X2 against the biasing force of the coil spring 61 due to the water pressure. When the water W flows out of the first space 21A, the water pressure in the first space 21A decreases, and the diaphragm 24 is displaced toward the outer side X2 against the biasing force of the coil spring 61.

[0040] The water detection unit 20 detects the inflow of the water W into the first space 21A of the pressure detection chamber 21 by detecting the pressure difference between the first space 21A and the second space 21B. For example, as shown in FIG. 5, the second head h2 after the water W has flowed into the first space 21A (when a tsunami has occurred) is detected, and a water pressure change (pressure change) is detected from the head difference Δh (=h2-h1) between the second head h2 and the first head h1 before the water W has flowed into the first space 21A (when no tsunami has occurred). When the water pressure change is detected at this time, the first space 21A is filled with the water W, and the diaphragm 24 is displaced to the outside X2 against the bias of the coil spring 61 due to the water pressure. For example, the water pressure at which the shutoff valve 1 operates is set to be greater than 0 kPa and equal to or less than 2.0 kPa.

[0041] FIG. 6 is a vertical cross-sectional view showing the shutoff valve 1 in which a filter 25 and a strainer 26 are provided at the inlet 22. As shown in FIG. As shown in Fig. 6, the inlet 22 has a mesh filter 25 and a cylindrical strainer 26 with slits or small holes that cover the filter 25 from the outer periphery. The filter 25 is cone-shaped. By providing the filter 25 and the strainer 26 at the inlet 22, it is possible to prevent drifting objects such as wood chips, leaves, mud, and pebbles contained in the tsunami water W from entering the first space 21A of the pressure detection chamber 21 while allowing the water W to pass through. This makes it possible to prevent a problem in which the water W does not flow into the pressure detection chamber 21 due to clogging of the inlet 22 with garbage, sticking of leaves, etc.

[0042] FIG. 7 is a vertical cross-sectional view showing the shutoff valve 1 in which an air vent hole 55 is provided at the outlet port 23. As shown in FIG. As shown in Fig. 7, the outlet 23 is provided with an air vent hole 55 (check valve) that prevents the inflow of gas or liquid from the outside. Here, in Fig. 7, the outlet 23 is provided in the second hood body 52. ​​The air vent hole 55 extends upward from the outlet 23, turns back at a U-shaped turning portion 55a, and further extends downward. Because the tip opening 55b of the air vent hole 55 faces downward, it is possible to prevent water during precipitation from flowing into the second space 21B through the air vent hole 55.

[0043] The operation of the shutoff valve 1 having the above-mentioned configuration will be described. 5, when water W flows from the inlet 22 into the first space 21A of the pressure detection chamber 21 inside the hood portion 50 in the event of flooding, the diaphragm 24 is displaced toward the second space 21B (outside X2) by the pressure of the water W. At this time, the pressure of the water W flowing into the first space 21A becomes greater than the spring force (biasing force) of the coil spring 61. Therefore, the diaphragm 24 is displaced toward the outside X2 against the biasing force of the coil spring 61. At this time, the gas E in the second space 21B flows out from the outlet 23 to the outside.

[0044] When the diaphragm 24 moves outward X2 in the axial direction X, the lock operation piece 342 of the lock mechanism 34 fixed to the first support plate 62A that supports the diaphragm 24 also moves outward X2. Then, the movement of the lock operation piece 342 releases the lock of the lock operating portion 341 of the lock mechanism 34.

[0045] Next, when the locking mechanism 34 is released, as shown in Fig. 3, the valve body support shaft 31 and the valve body 33 are lowered by the biasing force of a biasing member (not shown), and the valve body 33 is pressed against the valve seat 433a formed in the central communication part 433 of the flow path 43. In other words, the valve body 33 moves from the open position P1 (see Fig. 2) to the closed position P2, and even if a power outage occurs during a flood disaster such as a tsunami, the water W due to the tsunami can be detected and the flow path 43 in the cutoff part 30 can be reliably cut off.

[0046] Thereafter, the manual gate valve 13 (see FIG. 1) is closed to prevent the liquid M, such as fuel, from flowing out of the tank 10. The shutoff valve 1 is removed from the piping 11 and replaced with a new one. The shutoff valve 1 may be reused by replacing the replacement parts.

[0047] Next, the operation of the shutoff valve 1 will be described in detail with reference to the drawings. The shutoff valve 1 according to this embodiment shuts off a flow path of a pipe 11 provided in a tank 10 that stores liquid M. The shutoff valve includes a pressure detection chamber 21 that is partially open to the atmosphere, and includes a water detection unit 29 that detects flooding of the tank 10 based on a change in pressure caused by the inflow of water W from the outside into the pressure detection chamber 21 and the outflow of gas E from the pressure detection chamber 21 to the atmosphere due to the inflow of water W, and a shutoff unit 30 that operates based on the flooding detected by the water detection unit 20 and shuts off a flow path 43 through which the liquid M stored in the tank 10 flows.

[0048] According to the shutoff valve 1 of this embodiment, the water detection unit 20 detects that the tank 10 is flooded by the pressure change caused by the inflow of water W into the pressure detection chamber 21 and the outflow of gas E, and the flooding can be detected by a mechanical configuration rather than an electrical configuration. Then, the shutoff unit 30 can be operated to shut off the flow path 43 by the detection of flooding by the water detection unit 20. Therefore, in this embodiment, the shutoff valve 1 itself detects the water pressure in the pressure detection chamber 21 at this time when the water level rises due to flooding such as a tsunami, and water W flows into the pressure detection chamber 21. Therefore, electric and pneumatic equipment as in the past is not required, and there is no need to make these equipment explosion-proof, so the cost of the equipment can be reduced. Thus, in this embodiment, even if the tank 10, the shutoff valve 1, and the piping 11 are flooded due to flooding or the like, the outflow of the liquid M in the tank 10 can be prevented by a low-cost structure.

[0049] In addition, in this embodiment, the pressure detection chamber 21 has an inlet 22 that is open to the atmosphere and through which water W flows in from the outside, and an outlet 23 that is provided above the inlet 22, is open to the atmosphere, and through which gas E flows out. Therefore, when a flood such as a tsunami occurs, water W flows into the pressure detection chamber 21 from the inlet 22, and the gas E in the pressure detection chamber 21 can be discharged into the atmosphere from the outlet 23 located above the inlet 22. Therefore, since water accumulates in the pressure detection chamber 21 when a flood occurs, by detecting the pressure change caused by the water W flowing into the pressure detection chamber 21, it is possible to detect flooding of the tank 10, the shutoff valve 1 and its piping 11.

[0050] In this embodiment, the diaphragm 24 separates the first space 21A on the inlet 22 side from the second space 21B on the outlet 23 side. The diaphragm 24 detects the differential pressure between the first space 21A and the second space 21B. Therefore, when a flood such as a tsunami occurs and the water level rises, water W flows into the first space 21A of the pressure detection chamber 21 from the inlet 22, and gas E in the second space 21B of the pressure detection chamber 21 can be discharged to the atmosphere from the outlet 23 located above the inlet 22. That is, the water pressure caused by the water W flowing into the first space 21A during a flood causes the diaphragm 24 separating the first space 21A and the second space 21B to be pushed toward the second space 21B, and gas E in the second space 21B can be discharged from the outlet 23. The pressure difference between the first space 21A and the second space 21B can be detected from the amount of displacement of the diaphragm 24 at this time, and thus flooding of the shutoff valve 1 can be detected.

[0051] In this embodiment, the outlet 23 is provided with an air vent hole 55 that prevents the inflow of gas or liquid from the outside. In this embodiment, since the air vent hole 55 is provided in the outlet 23, the gas E in the pressure detection chamber 21 can be reliably discharged to the outside, and gas or liquid from the outside can be prevented from flowing into the pressure detection chamber 21 from the outlet 23. In other words, since only the water W flows into the pressure detection chamber 21 from the inlet 22, only the pressure change due to the water flowing into the pressure detection chamber 21 can be accurately detected.

[0052] In addition, this embodiment further includes a hood portion 50 that is formed to cover the water detection portion 20 and prevents water from entering the pressure detection chamber 21 when precipitation from above, while allowing water to enter the pressure detection chamber 21 when water W flows in from below. In this way, since the hood portion 50 that covers the water detection unit 20 is provided, it is possible to prevent the pressure detection chamber 21 from being flooded by rainfall from above, and to prevent malfunction. Furthermore, by providing the hood portion 50, the water W that flows in from below can be filled into the pressure detection chamber 21 without being allowed to flow out to the outside. As a result, only water flows into the pressure detection chamber 21 from the inlet 22, and therefore only the pressure change due to the water flowing into the pressure detection chamber 21 can be accurately detected.

[0053] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention.

[0054] For example, in this embodiment, the differential pressure between the first space 21A and the second space 21B is used as the water detection method of the water detector 20, but this is only one example and other detection methods can be adopted. For example, it is also possible to adopt a water detection method that detects the value of the spring force of the coil spring 61, which changes depending on the pressing force of the diaphragm 24. For example, as described above, the pressure difference between the water pressure and the spring force of the coil spring or the like may be set in the range of more than 0 kPa and less than or equal to 2.0 kPa. In other words, when the spring force is 1.0 kPa, the diaphragm 24 is pressed toward the second space 21B when the water pressure of the water W flowing into the first space 21A exceeds 1.0 kPa.

[0055] In addition, in this embodiment, the inlet 22 is disposed on one of the left and right sides of the hood portion 50 as viewed from the axial direction X, but it may be disposed on both the left and right sides. That is, the inlet 22 is not limited to being disposed at one location, and multiple inlets may be provided. In addition, the inlet 22 is not limited to being opened downward, and may be opened sideways.

[0056] Furthermore, in this embodiment, the air vent hole 55 having the folded-back portion 55a bent downward is used as the check valve provided at the outlet 23, but the present invention is not limited to this configuration. As another configuration of the check valve, for example, a check valve configured to be sealed at the tip of a pipe extending vertically upward from the outlet 23 with a material that can be broken by the pressure of the gas E pushed out from the second space 21B can be used. [Explanation of symbols]

[0057] 1 shutoff valve (shutoff valve for tank), 10 tank, 11 piping, 20 water detection part, 21 pressure detection chamber, 21A first space, 21B second space, 22 inlet, 23 outlet, 24 diaphragm, 25 filter, 26 strainer, 30 shutoff part, 31 valve body support shaft, 33 valve body, 34 lock mechanism, 40 valve body, 43 flow path, 50 hood part, 55 air vent hole (check valve), 61 coil spring, 5 guide part, 433 central communication part, 433a valve seat, E gas, M liquid, O diaphragm axis, X axial direction, W water

Claims

1. A tank shutoff valve that shuts off a flow path of a pipe provided in a tank that stores a liquid, a water detection unit that includes a pressure detection chamber that is partially open to the atmosphere and detects flooding of the tank based on a change in pressure caused by an inflow of water from the outside into the pressure detection chamber and an outflow of gas from the pressure detection chamber to the atmosphere due to the inflow of water; a blocking unit that operates based on the flooding detected by the water detection unit and blocks the flow path through which the liquid stored in the tank flows; Equipped with The blocking portion is movable between an open position at which the flow path is opened and a closed position at which the flow path is closed, and is biased toward the closed position, a locking mechanism is provided to lock the blocking unit in the open position; The lock mechanism includes a lock operation unit and a lock operation unit that transmits a change in water pressure detected by the water detection unit to the lock operation unit. The lock operation unit is operated by a change in water pressure detected by the water detection unit to operate the lock action unit, whereby the lock mechanism is unlocked and the blocking unit is brought into the closed position. Tank shutoff valve.

2. The pressure detection chamber is an inlet that is open to the atmosphere and through which water flows in from the outside; An outlet provided above the inlet, open to the atmosphere, and through which gas flows out.

2. The tank shutoff valve of claim 1.

3. The pressure detection chamber is an inlet that is open to the atmosphere and through which water flows in from the outside; an outlet port that is open to the atmosphere and through which gas flows out of the pressure detection chamber; a diaphragm separating a first space on the inlet side from a second space on the outlet side, The diaphragm detects a differential pressure between the first space and the second space.

2. The tank shutoff valve of claim 1.

4. The outlet is provided with a check valve to prevent the inflow of gas or liquid from the outside.

4. A tank shutoff valve according to claim 2 or 3.

5. a hood portion formed to cover the water detection portion and prevent water from entering the pressure detection chamber when rain falls from above, while allowing water to enter the pressure detection chamber when water flows in from below; 2. The tank shutoff valve of claim 1.

Images