JP7630419B2 - Water-submersion detection cutoff device - Google Patents

Description

The present invention relates to a submersion detection and shutoff device that can shut off gas piping that carries gas when the piping is submerged in water.

Conventionally, as shown in Patent Document 1, there has been known an emergency shutoff device capable of emergency shutoff of a fluid flow pipe through which a fluid flows. This emergency shutoff device divides the inside of a housing into a first chamber and a second chamber by a diaphragm, provides a pressure setting spring in the second chamber for pressing the diaphragm from the second chamber side to the first chamber side, and is configured to be able to introduce fluid flowing through the fluid flow pipe into the first chamber.
The emergency shutoff device is configured to be able to perform emergency shutoff of the fluid flow pipe and release the emergency shutoff by triggering the diaphragm to move along the biasing direction of the pressure setting spring in response to the pressure of the fluid flowing into the first chamber (see Patent Document 1).

Japanese Patent Application Publication No. 09-014492

In emergency shutoff devices equipped with a diaphragm as described above, the pressure-receiving surface of the diaphragm may be installed in a direction other than horizontal (for example, vertical) due to installation space and other factors. In this case, the fluid such as water that flows into the first chamber is subjected to a higher pressure on the pressure-receiving surface of the diaphragm the lower it is in the depth direction, and pressure is not applied evenly to the entire pressure-receiving surface of the diaphragm, so the diaphragm does not stroke smoothly in the biasing direction of the pressure setting spring, and there are cases in which it is unable to perform a good shutoff function.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a submersion detection shutoff device that can be designed to allow smooth stroking by applying only a certain pressure associated with submersion to the diaphragm when it is submerged due to flooding or the like, and that can effectively perform the shutoff function of the gas piping.

In order to achieve the above object, the submersion detection and cutoff device comprises:
A submersion detection and shutoff device that can shut off a gas pipe through which gas flows when the gas pipe is submerged in water, and its characteristic configuration is as follows:
a valve body that opens and closes the gas piping, a diaphragm, a pressure setting spring that can bias the diaphragm from the first chamber side to the second chamber side with respect to a housing that is partitioned into a first chamber and a second chamber by the diaphragm, and a mechanism that shuts off the valve body by the stroke of the diaphragm,
The housing constituting the second chamber includes an orifice that communicates between the outside and the second chamber,
an inner diameter of the orifice is set to a diameter that allows water to enter the second chamber from the outside when a water level due to submersion is higher than a vertical height position of the orifice and a head pressure applied to the orifice exceeds an internal pressure of the second chamber, and prohibits water from entering the second chamber from the outside when the head pressure applied to the orifice is equal to or lower than the internal pressure of the second chamber;
an atmospheric pressure equalizing tube having one end connected to the communication hole provided in the housing constituting the first chamber and an atmospheric vent hole at the other end is connected, the atmospheric vent hole being located above the orifice;
The atmospheric vent hole is provided at a position higher than the estimated flood water level set in a hazard map for the installation position of the housing.

According to the above characteristic configuration, when the submersion detection cutoff device according to the present invention is submerged due to flood damage, etc., even if the head pressure applied to the orifice becomes almost equal to the internal pressure of the second chamber, the surface tension of the water can be prevented from replacing the internal gas with water, making it possible to design the diaphragm to be subjected to only the head pressure of the orifice. If the diaphragm strokes, water will be allowed to enter, but by adopting a configuration in which a reservoir tank is provided in communication with the housing, for example, the invaded water will accumulate in the reservoir tank, thereby realizing a configuration that does not adversely affect the pressure acting on the diaphragm.
Furthermore, according to the above characteristic configuration, even if flood damage occurs, as long as the flood water level is less than the estimated flood water, water will not enter the first chamber, and the pressure inside the first chamber can be set to atmospheric pressure, so the submersion detection and shutdown function can be performed well.

Further characteristic configurations of the water submersion detection cutoff device include:
a discharge port that discharges the water that has flowed into the second chamber through the orifice from the second chamber, and a storage tank that stores the water discharged from the discharge port,
The discharge port is provided vertically below the orifice.

According to the above characteristic configuration, for example, when the submersion detection shutoff device of the present invention is submerged, the head pressure applied to the orifice can be applied to the second chamber, the increase in pressure in the second chamber displaces the diaphragm, and the displacement of the diaphragm brings the valve body into a closed state, thereby achieving good submersion shutoff.
At this time, water flows into the second chamber from the orifice located vertically above, and the water is discharged from an outlet located vertically below the orifice and stored in the storage tank, so water does not remain in the second chamber. This makes it possible to prevent different water pressures from being applied to the diaphragm in the vertical direction. This makes it possible to apply the internal pressure of the second chamber evenly to the entire pressure-receiving surface of the diaphragm even when the device is submerged in water. This effect is well exhibited regardless of the angle of the pressure-receiving surface of the diaphragm relative to the horizontal direction.

To achieve the above-mentioned effect, it is preferable that the inner diameter of the orifice is set to, for example, 3 mm or more and 7 mm or less.

Further characteristic configurations of the water submersion detection cutoff device include:
The diaphragm is disposed such that the pressure-receiving surface is aligned along a direction intersecting the horizontal direction.

The submersion detection and shutoff device having the characteristic configuration described so far can perform the submersion shutoff function well even if the pressure-receiving surface of the diaphragm is installed along a direction that intersects the horizontal direction (including, for example, the vertical direction), so various installation conditions can be tolerated and the degree of freedom during installation can be improved.

Further characteristic configurations of the water submersion detection cutoff device include:
The set pressure used to bias the diaphragm by the pressure setting spring is set to be smaller than the head pressure derived from the difference between the expected flooding water level set in a hazard map at the installation position of the housing and the vertical height position of the orifice.

As in the above characteristic configuration, by setting the set pressure for biasing the diaphragm by the pressure setting spring to a value smaller than the head pressure derived from the difference between the expected flood water level set in the hazard map at the installation position of the housing and the vertical height position of the orifice, at least when the expected flood water level expected in the event of a flood is reached, the diaphragm is displaced by increasing the pressure in the second chamber, transitioning the valve body to a closed state and successfully shutting off the gas piping by submersion.

1 is a schematic diagram of a water submersion detection and interruption device according to an embodiment of the present invention;

The submersion detection shutoff device 100 according to an embodiment of the present invention is designed to allow a smooth stroke when submerged due to flooding or the like by applying only a specified pressure associated with submersion to the diaphragm, thereby enabling the device to perform a good gas piping shutoff function.
Hereinafter, a water submersion detection and blocking device 100 according to an embodiment will be described with reference to the drawings.

1, the submersion detection and cutoff device 100 according to this embodiment is configured by modifying a normally open direct acting governor, and includes a valve body Va that can be seated on a valve seat Vb formed inside a gas pipe L1 through which gas (e.g., city gas 13A) flows, a valve shaft Vc that is provided along the opening/closing movement direction of the valve body Va, and a diaphragm A that is connected to the valve shaft Vc. The valve shaft Vc is provided with a seal member 12 between it and the gas pipe L1, and is disposed so as to be slidable relative to the gas pipe L1.
Incidentally, the diaphragm A is disposed so that the pressure receiving surface is aligned along a direction intersecting the horizontal direction (in this embodiment, the vertical direction along the arrow Z). Also, the valve axis Vc is disposed along the horizontal direction.

The diaphragm A divides the interior of the housing 10 into a first chamber K1 and a second chamber K2.
The first chamber K1 is provided with a pressure setting spring S which urges the diaphragm A from the first chamber K1 to the second chamber K2 with one end abutting against the diaphragm A and the other end abutting against a saucer Sa provided in the first chamber K1. The saucer Sa is configured to be movable in a displacement direction (arrow Y direction in FIG. 1) by rotating while being screwed into a female screw portion 10a formed on the inner wall of the first chamber K1, and the urging force of the pressure setting spring S on the diaphragm A is adjusted by moving the saucer Sa in the displacement direction.
The housing 10 constituting the first chamber K1 is provided with a communication hole 20b, and an atmospheric pressure equalizing tube 20 having one end connected to the communication hole 20b and an atmospheric vent hole 20a located above the communication hole 20b is connected to the communication hole 20b. With this configuration, the first chamber K1 is maintained at atmospheric pressure.
Here, the atmospheric vent hole 20a of the atmospheric equalization pipe 20 is located above the orifice O, and is provided at a position (X3 in Figure 1) higher than the expected flooding water level (X2 in Figure 1) set in the hazard map at the installation position of the housing 10 (the cut-off position where the gas piping L1 is cut off).

Furthermore, the housing 10 constituting the second chamber K2 has an orifice O that connects the outside with the second chamber K2, an outlet C1 that discharges water that has flowed into the second chamber K2 via the orifice O from the second chamber K2, and a storage tank C that stores the water discharged from the outlet C1. The outlet C1 is provided vertically below the orifice O. More preferably, the outlet C1 is provided at the lowest position in the vertical direction of the housing 10 constituting the second chamber K2.

In the above configuration, when the orifice O is in a natural state where it is not submerged, the position of the tray Sa is adjusted in the displacement direction so that the valve body Va is in an open state (preferably fully open state), and the biasing force of the pressure setting spring S is set.

Furthermore, the inner diameter X4 of the orifice O is set to a diameter that allows water to enter the second chamber K2 from the outside when the head pressure applied to the orifice O exceeds the internal pressure of the second chamber K2 in a case where the water level due to submersion (height from the ground G to the water surface: X2) is higher than the vertical height position of the orifice O (height position from the ground G: X1) and prohibits water from entering the second chamber K2 from the outside when the head pressure applied to the orifice O is equal to or lower than the internal pressure of the second chamber K2. Specifically, the inner diameter X4 of the orifice O is set to be 3 mm or more and 7 mm or less.
Here, the head pressure means the water pressure acting on the orifice O when the orifice O is submerged in water.
In particular, even if the head pressure applied to the orifice O becomes approximately equal to the internal pressure of the second chamber K2, the surface tension of the water can be prevented from replacing the internal gas (air) with water, making it possible to design the diaphragm A to be subjected to only the head pressure of the orifice O. If the diaphragm A strokes, water will be allowed to enter, but the invading water will accumulate in the reservoir C and will not adversely affect the pressure acting on the diaphragm A.

Incidentally, when the water level (height from the ground G to the water surface: X2) due to submersion is higher than the vertical height position of the orifice O (height position from the ground G: X1), it is preferable that the inner diameter X4 of the orifice O allows water to enter the second chamber K2 from the outside when the head pressure applied to the orifice O exceeds the internal pressure of the second chamber K2 and can suppress the outflow of gas (air in this embodiment) inside the second chamber K2 to the outside. As a result, when water enters the second chamber K2 and the gas inside the second chamber K2 does not flow out to the outside, the pressure inside the second chamber K2 increases by the volume of water that has flowed into the second chamber K2, and the diaphragm A is pressed from the second chamber K2 side to the first chamber K1 side, and the valve body Va transitions from the open state to the closed state.

In this embodiment, the set pressure used to bias the diaphragm A by the pressure setting spring S is set to be smaller than (and preferably equal to) the head pressure derived from the difference between the expected flooding water level (X2 in Figure 1) set in the hazard map at the installation position of the housing 10 and the vertical height position of the orifice O (X1 in Figure 1).
As a result, in the event of a flood exceeding at least the expected water level, water will enter the second chamber K2, causing the diaphragm A to displace against the biasing force of the pressure setting spring S, and the valve body Va will transition to a closed state.
Incidentally, the internal volume of the storage tank C is determined based on the head pressure and the pressure of the second chamber K2 before the water is submerged. More specifically, the internal volume of the storage tank C is set to a volume that is sufficiently larger than the total volume of water that will enter the second chamber K2 when the internal pressure after the pressure of the second chamber K2 is increased becomes equal to the head pressure and the water intrusion stops.

[Another embodiment]
(1) In the above embodiment, the diaphragm A is provided with its pressure-receiving surface extending along the vertical direction. However, the pressure-receiving surface may extend along a direction intersecting the horizontal direction.
In other words, the pressure receiving surface of the diaphragm A may be provided at any angle as long as the water flowing from the orifice O into the second chamber K2 has an inclination such that it is guided to the storage tank C.

(2) In the above embodiment, the inner diameter X4 of the orifice O is set to be equal to or greater than 3 mm and equal to or less than 7 mm. However, the inner diameter X4 is not limited to this value.
For example, the inner diameter X4 of the orifice O may be set to be greater than 5 mm, and a filter having a predetermined mesh size may be disposed in the orifice O.

(3) In the above embodiment, the height position of the atmospheric vent hole 20a of the atmospheric equalizing pipe 20 from the ground G and the set pressure of the pressure setting spring S were set based on the expected water level of flooding at the installation position of the submersion detection and blocking device 100 on the hazard map.
As another configuration example, the height position of the atmospheric vent hole 20a of the atmospheric equalization pipe 20 from the ground G and the set pressure by the pressure setting spring S may be set based on the water level obtained by multiplying the estimated flood water level according to the hazard map by a predetermined set adjustment rate.

(4) In the above embodiment, the submersion detection and shutoff device 100 may be configured to include a valve body Va that can seat on a valve seat Vb formed inside a gas pipe L1 through which a gas (e.g., city gas 13A) flows, a diaphragm A, a pressure setting spring S that can urge the diaphragm A from the first chamber K1 side to the second chamber K2 side with respect to a housing 10 that is partitioned by the diaphragm A into a first chamber K1 and a second chamber K2, and a mechanism (not shown) that shuts off the valve body Va by the stroke of the diaphragm A.
That is, the valve closing function may be performed by a spring (not shown) dedicated to the valve closing function, with the stroke of diaphragm A serving as the operation trigger (e.g., releasing the latch).

(5) In the above embodiment, the atmospheric pressure equalizing tube 20 is configured to have an atmospheric vent hole 20a located above the communication hole 20b, but is not limited to this configuration.

The configurations disclosed in the above embodiment (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. Appropriate modifications can be made without departing from the scope of the present invention.

The submersion detection shutoff device of the present invention can be designed so that when it is submerged due to flooding or the like, only the specified pressure associated with submersion acts on the diaphragm, allowing for smooth stroking, and can be effectively used as a submersion detection shutoff device that can effectively perform the shutoff function of gas piping.

10: Housing 20: Atmospheric pressure equalizing pipe 20a: Atmospheric vent hole 20b: Communication hole 100: Submersion detection cutoff device A: Diaphragm C: Storage tank K1: First chamber K2: Second chamber L1: Gas pipe O: Orifice S: Pressure setting spring Va: Valve body Vb: Valve seat Vc: Valve stem X4: Inner diameter

Claims (5)

A submersion detection and shutoff device capable of shutting off a gas pipe through which gas flows when the gas pipe is submerged,
a valve body that opens and closes the gas piping, a diaphragm, a pressure setting spring that can bias the diaphragm from the first chamber side to the second chamber side with respect to a housing that is partitioned into a first chamber and a second chamber by the diaphragm, and a mechanism that shuts off the valve body by the stroke of the diaphragm,
The housing constituting the second chamber includes an orifice that communicates between the outside and the second chamber,
an inner diameter of the orifice is set to a diameter that allows water to enter the second chamber from the outside when a water level due to submersion is higher than a vertical height position of the orifice and a head pressure applied to the orifice exceeds an internal pressure of the second chamber, and prohibits water from entering the second chamber from the outside when the head pressure applied to the orifice is equal to or lower than the internal pressure of the second chamber;
an atmospheric pressure equalizing tube having one end connected to the communication hole provided in the housing constituting the first chamber and an atmospheric vent hole at the other end is connected, the atmospheric vent hole being located above the orifice;
The atmospheric vent hole is provided at a position higher than the estimated flood water level set in a hazard map for the installation position of the casing. a discharge port that discharges the water that has flowed into the second chamber through the orifice from the second chamber, and a storage tank that stores the water discharged from the discharge port,
The submersion detection and cutoff device according to claim 1 , wherein the outlet is provided vertically below the orifice. The submersion detection and interruption device according to claim 1 or 2, wherein the inner diameter of the orifice is set to 3 mm or more and 7 mm or less. The submersion detection cutoff device according to any one of claims 1 to 3, wherein the diaphragm is installed so that the pressure-receiving surface is aligned along a cross direction that crosses the horizontal direction. The submersion detection and cutoff device according to any one of claims 1 to 4, wherein the set pressure for biasing the diaphragm by the pressure setting spring is set to be smaller than the head pressure derived from the difference between the expected flood water level set in a hazard map at the installation position of the housing and the vertical height position of the orifice.

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