Water flow detector

Abstract

To provide a water flow detector capable of performing maintenance on a primary side pipe, without the need of closing a valve on a secondary side pipe, even in a case of performing drain in the primary side pipe in inspection of a sprinkler facility.SOLUTION: A water flow detector comprises: a water flow detector body having a first valve body; a bypass pipe which couples and communicates, a primary side and a secondary side partitioned by the first valve body of the water flow detector body, in a state of avoiding the first valve body; and a relief valve which is provided on the bypass pipe. The relief valve comprises: a relief valve body which has a secondary side communication part, a primary side communication part, and a communication chamber for communicating and coupling the secondary side communication part and the primary side communication part; and a second valve body which is arranged in the communication chamber, closes the secondary side communication part in normal time, and if a pressure in the secondary side pipe of the sprinkler pipe becomes equal to or greater than a preset pressure, communicates the secondary side communication part and the primary side communication part by the water pressure in the secondary side pipe.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a flowing water detection device used in sprinkler equipment.

Background Art

[0002] Conventionally, in sprinkler equipment, a flowing water detection device is installed in a sprinkler pipe that connects a water source such as a fire-fighting water storage tank and a sprinkler head. The flowing water detection device has a check valve structure and allows only one-way water flow from the water source to the sprinkler head.

[0003] In the secondary pipe where the sprinkler head is installed, the water filled inside expands and contracts due to seasonal temperature differences. In particular, in summer, the water in the secondary pipe expands and the pressure rises, which may cause damage to the sprinkler head, the secondary pipe, and their peripheral equipment, or leakage from these facilities. Also, in winter, when the volume expands due to the freezing of some of the water in the secondary pipe, the water in the pipe is compressed and the pressure rises, and similarly, the sprinkler head, the secondary pipe, and their peripheral equipment may be damaged or leakage may occur from these facilities.

[0004] To prevent the above situation, Patent Document 1 proposes providing a bypass flow path that bypasses the primary side and the secondary side of the flowing water detection device, installing a differential pressure valve in this bypass flow path, and opening the differential pressure valve when the pressure on the secondary side becomes higher than the pressure on the primary side by a predetermined amount or more, and discharging water from the secondary pipe to the primary pipe to prevent damage to the sprinkler head.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, for the maintenance of the sprinkler piping of the sprinkler equipment, when draining the water in the primary piping connected to the flowing water detection device, the pressure in the secondary piping relatively increases, the differential pressure valve opens, and water flows into the primary piping. Therefore, it is necessary to close all the valves provided in the secondary piping connected to the flowing water detection device, and there is a problem that the operation is complicated.

[0007] The present invention provides a flowing water detection device that does not require closing the valves on the secondary piping even when draining the water in the primary piping during inspection of the sprinkler equipment, and can easily perform maintenance of the primary piping.

Means for Solving the Problems

[0008] The flowing water detection device of the present invention is interposed between the primary piping and the secondary piping of the sprinkler piping, and normally blocks so as to partition the primary piping and the secondary piping, while communicating the primary piping with the secondary piping as the pressure on the secondary side decreases during a fire, and has a flowing water detection device main body having a first valve body; a bypass pipe that connects and communicates the primary piping and the secondary piping partitioned by the first valve body of the flowing water detection device main body, avoiding the first valve body; and a relief valve interposed in the bypass pipe. The relief valve has a relief valve main body having a secondary side communication part connected to the secondary piping of the sprinkler piping, a primary side communication part that opens intersecting the opening direction of the secondary side communication part and is connected to the primary piping of the sprinkler piping, and a communication chamber that connects and communicates the primary side communication part and the secondary side communication part. A second valve body is disposed in the communication chamber, which closes the secondary communication portion during normal times and is opened by the pressure in the secondary pipe of the sprinkler pipe when the pressure in the secondary pipe of the sprinkler pipe exceeds a preset allowable pressure, thereby communicating the secondary communication portion with the primary communication portion. It is characterized by this.

Effect of the Invention

[0009] In the flowing water detection device of the present invention, the flow and interruption of water between the primary communication portion and the secondary communication portion by the second valve body of the relief valve are performed based on the pressure in the secondary pipe to which the flowing water detection device is connected. Therefore, even when performing a draining operation for inspecting the primary pipe connected to the flowing water detection device, there is no need to perform an operation to prevent the inflow of water from the secondary pipe to the primary pipe through the relief valve installed in the bypass pipe, and the maintenance work of the primary pipe of the sprinkler pipe can be reduced.

[0010] As described above, since the opening of the relief valve of the flowing water detection device is performed based on the pressure in the secondary pipe, when a water leak occurs in the primary pipe of the sprinkler pipe and the pressure in the primary pipe decreases, even when the pressure in the secondary pipe becomes relatively higher than the pressure in the primary pipe, the relief valve of the flowing water detection device is not opened, and there is no inflow of water from the secondary pipe to the primary pipe through the relief valve.

[0011] Therefore, it is sufficient to inspect only the primary pipe of the sprinkler pipe, minimize the maintenance work of the sprinkler pipe, and improve the efficiency of the maintenance work.

[0012] Also, since the relief valve is configured to open when the pressure in the secondary pipe exceeds the allowable pressure, the shut-off state is maintained even when a draining operation is performed for inspecting the secondary pipe to which the flowing water detection device is connected and the pressure in the secondary pipe decreases.

[0013] Therefore, in order to prevent the first valve body of the flowing water detection device main body from opening, it is only necessary to close the valve on the primary side pipe or the secondary side pipe connected to the flowing water detection device main body, and there is no need to perform an operation to prevent the second valve body of the relief valve from opening, and the work can be reduced even in the maintenance of the secondary side pipe of the sprinkler pipe.

[0014] In the event of a fire, when water is discharged from the sprinkler head for fire extinguishing, the pressure in the secondary side pipe decreases. Along with this pressure decrease in the secondary side pipe, the first valve body of the flowing water detection device opens, and fire extinguishing water flows from the primary side pipe into the secondary side pipe.

[0015] On the other hand, in a conventional relief valve, when the difference between the pressure in the primary side pipe and the pressure in the secondary side pipe becomes equal to or greater than a predetermined pressure, it opens, and fire extinguishing water flows from the secondary side pipe into the primary side pipe. Therefore, as described above, when fire extinguishing water flows from the primary side pipe into the secondary side pipe, the pressure in the primary side pipe temporarily decreases, and there is a possibility that the difference between the pressure in the primary side pipe and the pressure in the secondary side pipe becomes equal to or greater than the predetermined pressure. In this case, a reverse flow from the secondary side pipe to the primary side pipe occurs, reducing the supply pressure of the fire extinguishing water to the sprinkler head, while the pressure in the primary side pipe increases due to the inflow of the fire extinguishing water through the relief valve, slowing down the pressure decrease in the primary side pipe and causing a problem that the start of the pump for pumping the fire extinguishing water from the fire extinguishing water storage tank to the sprinkler head is delayed.

[0016] On the other hand, in the flowing water detection device of the present invention, since the opening of the relief valve is not based on the pressure in the primary side pipe, even when the pressure in the primary side pipe decreases due to the inflow of the fire extinguishing water from the primary side pipe to the secondary side pipe during a fire, the relief valve will not open. The pump starts without delay in response to the pressure decrease in the primary side pipe, and the fire extinguishing water can be quickly supplied from the fire extinguishing water storage tank to the sprinkler head, enabling the initial fire extinguishing activities to be carried out smoothly.

[0017] In the above-mentioned water flow detection device, when the communication chamber of the relief valve body in the relief valve has an opening that is formed from the secondary-side communication portion toward the opening direction of the secondary-side communication portion and opens on the surface of the relief valve body, it is possible to maintain the second valve body disposed in the communication chamber through the opening without removing the entire relief valve from the bypass pipe, and the maintenance work of the relief valve of the water flow detection device can be smoothly performed.

[0018] In the above-mentioned water flow detection device, when the communication chamber has an annular expansion portion with an expanded inner diameter and this expansion portion is connected and communicated with the primary-side communication portion, when the second valve body retreats, the expansion portion communicates with the secondary-side communication portion through the communication chamber, the fire extinguishing water flowing in from the secondary-side communication portion flows into the expansion portion, and the fire extinguishing water can be smoothly introduced into the primary-side communication portion formed so that the opening direction intersects with respect to the secondary-side communication portion, and the pressure in the secondary-side pipe can be smoothly reduced and maintained in an appropriate state.

[0019] In the above-mentioned water flow detection device, when a lid is detachably disposed at the opening of the communication chamber in the relief valve body, by removing the lid, the maintenance inside the communication chamber can be performed, and the maintenance work of the relief valve can be smoothly performed without removing the entire relief valve from the bypass pipe.

[0020] In the above-mentioned water flow detection device, when a biasing member for biasing the second valve body in the direction of the secondary-side communication portion is disposed between the lid and the second valve body in the communication chamber of the relief valve, through the opening, the maintenance of the biasing member such as a spring is possible, and the maintenance work of the relief valve can be smoothly performed.

[0021] In the above-mentioned flowing water detection device, when the lid of the communication part is removed so that the second valve body and the biasing member can be removed from the communication chamber of the relief valve main body, by removing the lid, the entire relief valve can be removed from the bypass pipe. Without this, the second valve body and the biasing member can be taken out from the communication chamber of the relief valve main body, and maintenance work in the second valve body, the biasing member, the communication chamber, and the secondary side communication part can be easily performed.

[0022] Further, by biasing the second valve body toward the secondary side communication part by the biasing member, the communication between the secondary side communication part and the primary side communication part is blocked. By adjusting the biasing pressure with which the biasing member biases the second valve body, the allowable pressure of the fire extinguishing water in the secondary side pipe where the secondary side communication part is opened is adjusted.

[0023] On the other hand, when it is necessary to change the set pressure of the fire extinguishing water in the secondary side pipe due to renovation of the sprinkler equipment or the like, even in such a case, the flowing water detection device can be easily finely adjusted by taking out the biasing member from the communication chamber as needed without removing the entire relief valve from the bypass pipe.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0025] An example of the flowing water detection device of the present invention will be described with reference to the drawings. The flowing water detection device 2 is used for the sprinkler facility A shown in FIG. 1. The sprinkler pipe 1 has a primary side pipe 1a and a secondary side pipe 1b. The base end of the primary side pipe 1a is connected to the inside of the fire fighting water storage tank W, while the tip end thereof branches into a plurality of parts. And to each tip end 1a1 of the branched primary side pipe 1a, the secondary side pipe 1b is connected and communicated via the flowing water detection device 2 to form the sprinkler pipe 1, and each secondary side pipe 1b is arranged in each warning area. A plurality of sprinkler heads S are arranged at the respective tips of the secondary side pipes 1b.

[0026] A fire fighting pump P for supplying the fire fighting water in the fire fighting water storage tank W in the primary side pipe 1a to the sprinkler head S is interposed in the primary side pipe 1a. A pressure water tank Q is installed between the flowing water detection device 2 and the fire fighting pump P, and a pump start switch R is electrically connected to the pressure water tank Q. The pump start switch R operates to start the fire fighting pump P when the pressure of the fire fighting water in the primary side pipe 1a becomes equal to or lower than a predetermined pressure. Note that a pump control panel T for controlling the operation of the pump start switch R is electrically connected to the pump start switch R.

[0027] As shown in FIG. 2, in the cylindrical water flow detection device 2, a first valve body 22 with a swing chuck structure is disposed in the water flow detection device main body 21. The inside of the water flow detection device main body 21 is partitioned into a primary side chamber 21a and a secondary side chamber 21b by the first valve body 22. A primary side connection portion 21a2 for connecting the primary side pipe 1a of the sprinkler pipe 1 in a communicating state penetrates in the inner and outer directions in the primary side chamber 21a of the water flow detection device main body 21. Similarly, a secondary side connection portion 21b2 for connecting the secondary side pipe 1b of the sprinkler pipe 1 in a communicating state penetrates in the inner and outer directions in the secondary side chamber 21b of the water flow detection device main body 21. The first valve body 22 is formed in a disk shape and is normally closed, allowing only the flow of fire extinguishing water from the primary side pipe 1a (primary side chamber 21a) side to the secondary side pipe 1b (secondary side chamber 21b) side. The first valve body 22 is configured to open when the pressure in the primary side pipe 1a (primary side chamber 21a) becomes larger than the pressure in the secondary side pipe 1b (secondary side chamber 21b) by exceeding a predetermined pressure difference, and to be in a closed state in other states. In FIG. 2, the bypass pipe 3 and the relief valve 4 interposed therein are omitted.

[0028] As shown in FIGS. 3 and 4, a bypass pipe 3 is integrally provided on the main body 21 of the flowing water detection device 2 of the flowing water detection device. In the main body 21 of the flowing water detection device, a primary side through hole 21a1 that allows fire extinguishing water to flow through by communicating the primary side chamber 21a to the outside is formed separately from the primary side connection portion 21a2, and a secondary side through hole 21b1 that allows fire extinguishing water to flow through by communicating the secondary side chamber 21b to the outside is formed separately from the secondary side connection portion 21b2. One end of the bypass pipe 3 is connected and communicated with the inside of the primary side chamber 21a of the main body 21 of the flowing water detection device through the primary side through hole 21a1, and the other end of the bypass pipe 3 is connected and communicated with the inside of the secondary side chamber 21b of the main body 21 of the flowing water detection device through the secondary side through hole 21b1. The primary side chamber 21a and the secondary side chamber 21b of the main body 21 of the flowing water detection device are connected and communicated with each other in a state where the first valve body 22 is bypassed by the bypass pipe 3. Between the main body 21 of the flowing water detection device and one end of the bypass pipe 3, a valve 31 for opening and closing the bypass pipe 3 and a three-way joint 32 are interposed in order from the side of the main body 21 of the flowing water detection device. Similarly, between the main body 21 of the flowing water detection device and the other end of the bypass pipe 3, a valve 33 for opening and closing the bypass pipe 3 and a three-way joint 34 are interposed in order from the side of the main body 21 of the flowing water detection device. Pressure gauges K1 and K2 for measuring the pressure of the fire extinguishing water flowing through the bypass pipe 3 are respectively connected to the three-way joints 32 and 34.

[0029] A relief valve 4 is interposed between the three-way joints 32 and 34 in the bypass pipe 3. As shown in FIGS. 5 and 6, the relief valve 4 has a relief valve body 41 formed in a cylindrical shape. The relief valve body 41 has a through hole penetrating between both ends thereof, and one end portion of the through hole is enlarged in diameter to form a secondary side communication portion 42. One end of the secondary side communication portion 42 opens on the outer surface of one end of the relief valve body 41, a screw portion is formed on the inner peripheral surface of the secondary side communication portion 42, and the secondary side portion of the bypass pipe 3 is connected in a communicating state. The secondary side communication portion 42 of the relief valve body 41 is connected and communicated with the secondary side pipe 1b of the sprinkler pipe 1 through the secondary side chamber 21b of the main body 21 of the flowing water detection device.

[0030] A remaining portion of the through-hole of the relief valve body 41, excluding the secondary-side communication portion 42, is formed as a communication chamber 43. One end of the communication chamber 43 is connected and communicated with the secondary-side communication portion 42, and the other end opens on the outer surface of the other end of the relief valve body 41 on an extension line in the inflow direction of the fire-extinguishing water into the secondary-side communication portion 42 (the opening direction of the secondary-side communication portion 42).

[0031] A second valve body 5 is disposed in the communication chamber 43 of the relief valve body 41. An annular protrusion 53 protrudes from the outer peripheral surface of the base end portion of the second valve body 5. On the other hand, a lid body 43b is detachably disposed at the opening 43a at the other end of the communication chamber 43. A coil spring 6, which is a biasing member, is disposed in a compressed state between the protrusion 53 of the second valve body 5 and the lid body 43b, and constantly biases the second valve body 5 toward the secondary-side communication portion 42. The lid body 43b is screwed into the opening 43a at the other end of the communication chamber 43 so as to be able to advance and retreat, and is configured to be able to advance and retreat within the opening 43a at the other end of the communication chamber 43. By advancing and retreating the lid body 43b, the degree of compression of the coil spring 6 is adjusted, and the biasing force of the coil spring 6 on the second valve body 5 in the direction of the secondary-side communication portion 42 can be easily adjusted. An annular receiving step portion 43d is formed on the inner peripheral surface of the other end portion of the communication chamber 43 of the relief valve body 41. In a normal state, the second valve body 5 is disposed such that its protrusion 53 is pressed against the receiving step portion 43d of the communication chamber 43 by the biasing pressure of the coil spring 6, and the tip surface of the second valve body 5 is in a state close to the opening at the other end of the secondary-side communication portion 42.

[0032] On the base end surface of the second valve body 5, a columnar protrusion (for example, it may be a plate-shaped protrusion) having a certain length is formed as the position display portion 54. A through hole 43e penetrating in the inner and outer directions is formed in the lid body 43b portion facing the position display portion 54. The position display portion 54 of the second valve body 5 is disposed so as to be able to protrude and retract outward through the through hole 43e of the lid body 43b. When the second valve body 5 is in its normal (ordinary) disposed position, the end surface of the position display portion 54 of the second valve body 5 is located within the through hole 43e of the lid body 43b, and the whole is in a state of being accommodated within the through hole 43e (see Fig. 5). On the other hand, when the second valve body 5 retreats toward the expansion portion 43c (lid body 43b) side, a part of the position display portion 54 of the second valve body 5 protrudes outside from the outer opening end of the through hole 43e of the lid body 43b (see Fig. 6). Thus, by checking whether or not the position display portion 54 of the second valve body 5 protrudes outside from the outer opening end of the through hole 43e of the lid body 43b, the position of the second valve body 5 can be confirmed. When the position display portion 54 of the second valve body 5 protrudes outside from the outer opening end of the through hole 43e of the lid body 43b, since the pressure in the secondary piping 1b is higher than that in the normal state, if necessary, the sprinkler equipment A can be inspected to prevent an unexpected situation from occurring.

[0033] Further, an operation display portion (for example, a line, a symbol, a mark, etc.) (not shown) may be formed on the outer peripheral surface of the position display portion 54 of the second valve body 5, and when the second valve body 5 retreats and the secondary side communication portion 42 and the primary side communication portion 44 communicate with each other through the expansion portion 43c, it may be configured to be visible from the outside through the outer opening end of the through hole 43e of the lid body 43b. When the operation display portion of the second valve body 5 can be visually recognized from the outside, it can be clearly recognized that the pressure in the secondary piping 1b exceeds the allowable pressure, and if necessary, the sprinkler equipment A can be inspected to prevent an unexpected situation from occurring.

[0034] By removing the lid 43b disposed at the other end opening 43a of the communication chamber 43, the second valve body 5 and the coil spring 6 can be taken out from the communication chamber 43, and maintenance work of the second valve body 5 and the coil spring 6 and maintenance work inside the relief valve body 41 can be performed.

[0035] A gap through which fire extinguishing water can flow is formed between the outer peripheral surface of the second valve body 5 and the inner peripheral surface of the communication chamber 43 of the relief valve body 41 facing the second valve body 5. O-rings 51 and 52 are respectively disposed at the tip and the center of the outer peripheral surface of the second valve body 5. In a normal state, the gaps between the O-rings 51 and 52 of the second valve body 5 make the gap between the second valve body 5 and the inner peripheral surface of the communication chamber 43 facing the second valve body 5 be hermetically sealed over the entire circumference of the second valve body, and the secondary communication portion 42 and the primary communication portion 44 described later are hermetically blocked, and the fire extinguishing water is configured not to flow between the secondary communication portion 42 and the primary communication portion 44.

[0036] On the other hand, in the communication chamber 43, a groove-shaped expansion portion 43c is annularly recessed in a state where it is exposed on the inner peripheral surface of the communication chamber 43 by expanding the inner peripheral surface corresponding to between the O-rings 51 and 52 of the second valve body 5 in the normal arrangement position. In the relief valve body 41, a primary communication portion 44 having an inner opening 44a opening to the expansion portion 43c is formed. The outer end of the primary communication portion 44 opens to the outer surface of the relief valve body 41, a screw portion is formed on the inner peripheral surface of the primary communication portion 44, and the primary side portion of the bypass pipe 3 is connected in a communicating state. The primary communication portion 44 of the relief valve body 41 is connected and communicated with the primary side pipe 1a of the sprinkler pipe 1 through the primary side chamber 21a of the flowing water detection device body 21. The primary communication portion 44 is formed such that its opening direction intersects (preferably, is orthogonal to) the opening direction of the secondary communication portion 42. That is, the flow direction of the fire extinguishing water flowing through the primary communication portion 44 and the flow direction of the fire extinguishing water flowing through the secondary communication portion 42 are configured to intersect, preferably orthogonally.

[0037] Then, although the fire extinguishing water flowing into the primary-side communication part 44 presses the second valve body 5 through its inner opening 44a, since it presses in a direction intersecting the moving direction of the second valve body 5, the second valve body 5 does not move due to the fire extinguishing water flowing into the primary-side communication part 44.

[0038] Also, the fire extinguishing water flowing from the inner opening 44a of the primary-side communication part 44 into the expansion part 43c of the communication chamber 43 presses the outer peripheral surface of the second valve body 5 between the O-rings 51 and 52 of the second valve body 5. However, since the O-rings 51 and 52 are crimped to the inner peripheral surface of the communication chamber 43 so as to sandwich this pressing part from both sides and the second valve body 5 is positioned, the second valve body 5 can smoothly move forward and backward freely in the opening direction of the secondary-side communication part 42 despite the pressing by the fire extinguishing water flowing in through the primary-side communication part 44.

[0039] On the other hand, since the flow direction of the fire extinguishing water flowing into the relief valve 4 from the secondary-side communication part 42 is the moving direction of the second valve body 5, when the pressure of the fire extinguishing water flowing in from the secondary-side communication part 42 exceeds the biasing pressure of the coil spring 6, the second valve body 5 is configured to retreat in a direction away from the secondary-side communication part 42 by the pressure of the fire extinguishing water. When the second valve body 5 retreats due to the pressure of the fire extinguishing water and the O-ring 51 disposed on the tip side of the second valve body 5 reaches the expansion part 43c of the communication chamber 43, a gap is generated between the O-ring 51 and the inner peripheral surface of the communication chamber 43 facing it, and the secondary-side communication part 42 and the primary-side communication part 44 are in a state of being connected through the communication chamber 43 and the expansion part 43c, and the fire extinguishing water flowing in from the secondary-side communication part 42 is configured to flow into the primary-side communication part 44. Note that even when the second valve body 5 retreats and the secondary-side communication part 42 and the primary-side communication part 44 are in a connected state, a state where the gap between the outer peripheral surface of the second valve body 5 and the inner peripheral surface of the communication chamber 43 facing it is hermetically sealed over the entire circumference of the second valve body 5 by the O-ring 52 provided on the base end side of the second valve body 5 is maintained, and the fire extinguishing water does not flow into the other end side of the communication chamber 43 where the coil spring 6 is disposed.

[0040] When fire extinguishing water flows into the primary pipe 1a from the secondary pipe 1b of the bypass pipe 3 through the secondary communication part 42 and via the primary communication part 44, if the pressure in the secondary pipe 1b of the sprinkler pipe 1 decreases, the pressure of the fire extinguishing water flowing into the secondary communication part 42 also decreases. As a result, the biasing pressure of the coil spring 6 becomes greater than the pressure of the fire extinguishing water, and the second valve body 5 advances due to the biasing pressure of the coil spring 6. The protruding piece 53 of the second valve body 5 returns to the state where it is pressed against the receiving step part 43d of the communication chamber 43, and the O-rings 51 and 52 of the second valve body 5 are configured to return the secondary communication part 42 and the primary communication part 44 to a state where they are watertightly blocked.

[0041] Next, the usage instructions of the sprinkler facility A using the flowing water detection device 2 will be described. In the sprinkler facility A shown in Fig. 1, during normal times, the pressure (water pressure) in the primary pipe 1a of the sprinkler pipe 1 is the same as or slightly lower than the pressure (water pressure) in the secondary pipe 1b.

[0042] During normal times, the first valve body 22 of the flowing water detection device 2 is closed, and the primary chamber 21a (primary pipe 1a) and the secondary chamber 21b (secondary pipe 1b) are watertightly blocked by the first valve body 22. The second valve body 5 of the relief valve 4 of the flowing water detection device 2 is biased toward the secondary communication part 42 with a biasing pressure higher than the pressure in the secondary pipe 1b by the coil spring 6. Since the expansion part 43c is located between the O-rings 51 and 52 of the second valve body 5, it is in a state of being watertightly sealed by the O-ring 51 of the second valve body 5, and the primary communication part 44 and the secondary communication part 42 are watertightly blocked.

[0043] Even during normal times, in summer, the water in the secondary pipe 1b expands, or in winter, a part of the water in the secondary pipe 1b freezes, which may cause the pressure (water pressure) in the secondary pipe 1b to rise. If such a state is left unattended, there is a risk that the sprinkler head S, the secondary pipe 1b, and their peripheral equipment may be damaged or water leakage may occur from these equipment.

[0044] On the other hand, in the relief valve 4 of the water flow detection device 2, the biasing pressure of the coil spring 6 that biases the second valve body 5 toward the secondary side communication portion 42 is set to a pressure lower than the water pressure in the secondary side pipe 1b at which the facilities on the secondary side pipe 1b side including the sprinkler head S will be damaged (hereinafter sometimes referred to as "allowable pressure"). That is, the biasing pressure of the coil spring 6 is set to be greater than the normal pressure in the secondary side pipe 1b and below the allowable pressure during normal times.

[0045] As described above, when the water pressure in the secondary side pipe 1b rises for some reason and the pressure in the secondary side pipe 1b exceeds the allowable pressure, the pressure in the secondary side pipe 1b becomes greater than the biasing pressure of the coil spring 6. Due to the water pressure in the secondary side pipe 1b, the second valve body 5 retreats toward the expansion portion 43c side. When the O-ring 51 disposed on the tip side of the second valve body 5 reaches the expansion portion 43c, the secondary side communication portion 42 and the primary side communication portion 44 are connected and communicated through the communication chamber 43 and the expansion portion 43c, the bypass pipe 3 is opened, and the fire extinguishing water in the secondary side pipe 1b flows into the primary side pipe 1a side, reducing the pressure in the secondary side pipe 1b. Note that the first valve body 22 of the water flow detection device 2 is not opened even when the pressure in the secondary side pipe 1b increases, and maintains a closed state blocking the primary side chamber 21a and the secondary side chamber 21b. The pressure in the secondary side pipe 1b is reduced only by the amount of increase due to the opening of the second valve body 5 of the relief valve 4.

[0046] Then, when the pressure in the secondary side pipe 1b decreases and the biasing pressure of the coil spring 6 becomes greater than the water pressure in the secondary side pipe 1b, the second valve body 5 advances toward the secondary side communication portion 42 by the biasing pressure of the coil spring 6 and returns to the original state, and the O-ring 51 of the second valve body 5 watertightly blocks the secondary side communication portion 42 and the primary side communication portion 44.

[0047] In this way, when the pressure in the secondary side pipe 1b exceeds the allowable pressure, the second valve body 5 automatically retreats due to the pressure in the secondary side pipe 1b, allowing the fire extinguishing water in the secondary side pipe 1b to flow into the primary side pipe 1a side, thereby preventing damage to the facilities on the secondary side pipe 1b side.

[0048] When the second valve body 5 is operating, as shown in FIG. 6, a part of the position display portion 54 of the second valve body 5 protrudes outside from the outer opening end of the through hole 43e of the lid body 43b, and it is possible to confirm that an abnormality has occurred in the equipment on the secondary side pipe 1b side. Further, when an operation display portion is formed on the outer peripheral surface of the position display portion 54 of the second valve body 5, when the operation display portion of the second valve body 5 is visible from the outside, it is possible to clearly recognize that the pressure in the secondary side pipe 1b exceeds the allowable pressure. In this way, the state of the second valve body 5 can be confirmed by the position display portion 54 and / or the operation display portion, and if necessary, the sprinkler equipment A can be inspected to prevent an unexpected situation from occurring.

[0049] Also, in order to inspect the primary side pipe 1a of the sprinkler pipe 1, it may be necessary to drain the water inside the primary side pipe 1a. Draining the water inside the primary side pipe 1a increases the difference in internal pressure between the secondary side pipe 1b and the primary side pipe 1a. However, since the first valve body 22 of the flowing water detection device 2 maintains the blocked state as long as the pressure in the secondary side pipe 1b is greater than the pressure in the primary side pipe 1a, water flow between the primary side pipe 1a and the secondary side pipe 1b does not occur.

[0050] In the relief valve 4 of the flowing water detection device 2, the second valve body 5 advances and retreats according to the pressure in the secondary side pipe 1b and is not involved in the pressure in the primary side pipe 1a. Therefore, even if the pressure in the primary side pipe 1a decreases due to draining the water inside the primary side pipe 1a, the relief valve 4 maintains the closed (blocked) state, and water flow between the primary side pipe 1a and the secondary side pipe 1b does not occur.

[0051] Therefore, when inspecting the primary side pipe 1a by draining the water inside the primary side pipe 1a, there is no need to perform separate work to prevent the first valve body 22 of the flowing water detection device 2 and the second valve body 5 of the relief valve 4 from opening, and the maintenance work of the primary side pipe 1a of the sprinkler pipe 1 can be carried out smoothly.

[0052] In addition, in order to inspect the secondary piping 1b of the sprinkler piping 1, it may be necessary to drain the water from the secondary piping 1b. Since the second valve body 5 of the relief valve 4 of the flowing water detection device 2 is not opened even when the pressure in the secondary piping 1b becomes lower than normal, no work is required to maintain the closed (shut-off) state of the second valve body 5 of the relief valve 4 during the draining of the secondary piping 1b.

[0053] On the other hand, the first valve body 22 of the flowing water detection device 2 is opened when the pressure in the secondary piping 1b decreases and the difference between the pressure in the secondary piping 1b and the pressure in the primary piping 1a exceeds a preset pressure difference, and the fire extinguishing water flows from the primary piping 1a to the secondary piping 1b side. Therefore, it is necessary to close a valve (not shown in FIG. 1) installed in the primary piping 1a or the secondary piping 1b. However, as described above, since no separate work is required to avoid the opening of the second valve body 5 of the relief valve 4, the maintenance work of the secondary piping 1b can be reduced.

[0054] On the other hand, in the event of a fire, the sprinkler head S installed in the warning area where the fire has occurred is opened by the heat during the fire, and the fire extinguishing water filled in the secondary piping 1b of the sprinkler piping 1 is sprayed.

[0055] The pressure in the secondary piping 1b installed in the warning area where the fire has occurred decreases as the fire extinguishing water is sprayed from the sprinkler head S. As the pressure in the secondary piping 1b decreases, the pressure in the primary piping 1a relatively increases, and the first valve body 22 of the flowing water detection device 2 is opened, and the fire extinguishing water flows from the primary piping 1a to the secondary piping 1b.

[0056] On the other hand, as described above, the tip of the primary piping 1a is branched, and the secondary piping 1b is connected to each of the branched tips 1a1 of the primary piping 1a via the flowing water detection device 2. Therefore, the branched tips 1a1 of the primary piping 1a connected to each flowing water detection device 2 are connected and communicate with each other.

[0057] Therefore, when the first valve body 22 of any one of the flowing water detection devices 2 connected to each branched tip 1a1 of the primary side pipe 1a is opened and the fire extinguishing water flows into the secondary side pipe 1b from the primary side pipe 1a, the fire extinguishing water in the branched tip 1a1 of the primary side pipe 1a disposed in another warning area that is connected and communicated with each other flows into the branched tip 1a1 of the primary side pipe 1a to which the flowing water detection device 2 where the fire has occurred and the first valve body 22 is opened is connected. Accordingly, the pressure in the branched tip 1a1 of the primary side pipe 1a disposed in the warning area where no fire has occurred also decreases simultaneously.

[0058] When the pressure in the primary side pipe 1a decreases, the pressure in the secondary side pipe 1b becomes relatively higher, and the internal pressure difference between the primary side pipe 1a and the secondary side pipe 1b becomes larger. According to the conventional flowing water detection device, since the opening and closing of the relief valve provided in the flowing water detection device are performed based on the internal pressure difference between the primary side pipe 1a and the secondary side pipe 1b, as described above, even if the pressure in the secondary side pipe 1b has not increased, the decrease in the pressure in the primary side pipe 1a causes the internal pressure difference between the primary side pipe 1a and the secondary side pipe 1b to become larger, the relief valve is opened, and the fire extinguishing water flows from the secondary side pipe side into the primary side pipe side. As a result, the decrease in the pressure of the primary side pipe becomes slow.

[0059] When the pressure of the primary side pipe decreases, the pump start switch installed in the primary side pipe activates the fire extinguishing pump. However, as described above, the decrease in the pressure of the primary side pipe becomes slow, and the activation of the fire extinguishing pump by the pump start switch is delayed, which may hinder the initial fire extinguishing.

[0060] On the other hand, in the above-described flow water detection device 2 shown in FIGS. 2 to 6, the opening and closing of the relief valve 4 is performed based only on the pressure in the secondary side pipe 1b and does not depend on the pressure in the primary side pipe 1a. Therefore, when a fire occurs, the first valve body 22 of the flow water detection device 2 disposed in the warning area is opened, and the fire extinguishing water flows from the primary side pipe 1a into the secondary side pipe 1b. Even if the pressure in the tip 1a1 of the primary side pipe 1a disposed in the warning area where the fire has occurred and other warning areas decreases, all the relief valves 4 of the flow water detection device 2 disposed in the warning area maintain the closed (shut-off) state, and the fire extinguishing water does not flow from the secondary side pipe 1b side through the relief valve 4 into the primary side pipe 1a side. Therefore, the pump start switch R can sensitively detect the decrease in the pressure in the primary side pipe 1a caused by the fire, quickly start the fire extinguishing pump P, supply the fire extinguishing water in the fire extinguishing water storage tank W into the secondary side pipe 1b disposed in the warning area where the fire has occurred, and quickly perform the initial fire extinguishing of the fire through the sprinkler head S.

Explanation of Signs

[0061] 1 Sprinkler Pipe 1a Primary Side Pipe 1b Secondary Side Pipe 2 Flow Water Detection Device 21 Flow Water Detection Device Main Body 21a Primary Side Chamber 21a1 Primary Side Through Hole 21a1 Through Hole 21b Secondary Side Chamber 21b1 Secondary Side Through Hole 21b1 Through Hole 22 Valve Body 3 Bypass Pipe 4 Relief Valve 41 Relief Valve Main Body 42 Secondary Side Communication Port 43 Communication Chamber 43b Cover 43c Expansion Port 44 Primary Side Communication Port 5 Valve Body 51 O-ring 52 O-ring 53 Projection 54 Position Display Section 6 Biasing member (coil spring) A Sprinkler facility P Fire pump Q Pressure water tank R Pump start switch S Sprinkler head W Fire storage tank

Claims

1. A water flow detection device body having a first valve body interposed between a primary pipe and a secondary pipe of a sprinkler pipe and blocking the primary pipe and the secondary pipe from each other in normal times, while allowing the primary pipe to communicate with the secondary pipe as the pressure on the secondary side decreases during a fire; A bypass pipe that connects and communicates the primary pipe and the secondary pipe partitioned by the first valve body of the water flow detection device body, bypassing the first valve body; A relief valve interposed in the bypass pipe; The relief valve includes: A relief valve body having a secondary communication portion connected to the secondary pipe of the sprinkler pipe, a primary communication portion that opens intersecting the opening direction of the secondary communication portion and is connected to the primary pipe of the sprinkler pipe, and a communication chamber that connects and communicates the primary communication portion and the secondary communication portion; A second valve body disposed in the communication chamber that closes the secondary communication portion in normal times and is opened by the pressure in the secondary pipe of the sprinkler pipe when the pressure in the secondary pipe of the sprinkler pipe exceeds a preset allowable pressure, thereby communicating the secondary communication portion and the primary communication portion. The water flow detection device is characterized by this.

2. The communication chamber of the relief valve body in the relief valve has an opening portion formed from the secondary communication portion toward the opening direction of the secondary communication portion and opening on the surface of the relief valve body. The water flow detection device according to claim 1 is characterized by this.

3. The communication chamber has an annular expansion portion with an expanded inner diameter, and the water flow detection device according to claim 1 or claim 2 is characterized in that this expansion portion is connected and communicated with the primary communication portion.

4. A lid is detachably disposed at the opening portion of the communication chamber in the relief valve body. The water flow detection device according to claim 2 is characterized by this.

5. An urging member that urges the second valve body in the direction of the secondary communication portion is disposed between the lid and the second valve body in the communication chamber of the relief valve. The water flow detection device according to claim 4 is characterized by this.

6. The water flow detection device according to claim 5 is characterized in that the second valve body and the urging member can be taken out from the communication chamber of the relief valve body by removing the lid of the communication portion.

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