Fire hydrant system water discharge pressure testing device

Abstract

This invention provides a fire hydrant system water discharge pressure testing device that reduces pressure loss on the connection joint side compared to conventional products, allowing for a longer test hose than conventional products. [Solution] The fire hydrant system water discharge pressure testing device 1 according to the present invention comprises a connecting joint 3 connected to the maintenance valve of the fire hydrant system and a test hose 5 connected to the connecting joint 3. The connecting joint 3 includes an insert pipe 9 inserted into the connection port 21 of the maintenance valve, an orifice 13 provided on the secondary side of the insert pipe 9, a socket base 11 connected to the insert pipe 9 via the orifice 13, and a hose fitting 29 provided on the secondary side of the socket base 11 to which the test hose 5 is connected. The socket base 11 has a tapered flow path that expands in diameter from the insert pipe 9 side to the test hose 5 side, and the taper angle θ of the flow path is 60° or less.

Description

Technical Field

[0001] The present invention relates to a fire hydrant device water discharge pressure test device that is connected to a maintenance valve of a fire hydrant device to test the water discharge pressure of the fire hydrant device.

Background Art

[0002] Conventionally, fire hydrant devices have been installed as emergency equipment in tunnels such as motor vehicle roads. Inside the housing of the fire hydrant device, a fire hose having a nozzle at the tip, valves such as a fire hydrant valve and a pressure regulating valve, an opening and closing lever for operating the fire hydrant valve, etc. are accommodated.

[0003] At the time of installation and regular inspection of the fire hydrant device, a water discharge pressure test is performed to confirm whether water is discharged from the fire hose at a specified pressure. At that time, if the test is performed by actually passing water through a fire hose about 30 m long, it takes time for pulling out and storing the hose and treating the remaining water inside the hose. Therefore, a test valve (hereinafter referred to as a maintenance valve) is provided in the conventional fire hydrant device.

[0004] This maintenance valve is provided in the flowing water path between the fire hydrant valve and the fire hose. The maintenance valve has a connection port for passing water through the fire hose and a connection port for passing water through the water discharge pressure test device, and the secondary side flow path of the valve can be switched from the fire hose side to the water discharge pressure test device side.

[0005] A conventional water discharge pressure test device is disclosed in, for example, Patent Document 1. In the water discharge pressure test using such a water discharge pressure test device, the water discharge pressure test device is connected to the maintenance valve, the water supplied from the fire hydrant valve is passed through the water discharge pressure test device, and the water discharge pressure is confirmed and adjusted based on the value of the pressure gauge attached to the water discharge pressure test device.

[0006] The configuration of the conventional water discharge pressure test device 33 will be described based on FIGS. 4 to 6. Figure 4 shows the overall configuration of the water discharge pressure testing apparatus 33, with a partial cross-section shown. Figures 5 and 6 illustrate only the connecting joint 3 of the water discharge pressure test device 33. The upper half is an axial cross-section, and the lower half is a partial cross-sectional view showing the external appearance. Figure 5 shows the state before connection to the maintenance valve of the fire hydrant system, and Figure 6 shows the state after connection to the maintenance valve of the fire hydrant system. The dashed line in Figure 6 indicates the connection port 21 of the maintenance valve.

[0007] As shown in Figure 4, the conventional water discharge pressure testing device 33 consists of a connecting fitting 3 connected to a maintenance valve, a test hose 5 connected to the secondary side of the connecting fitting 3, and an instrument connection fitting 7 connected to the secondary side of the test hose 5. The water discharge pressure testing device 33 is used by inserting the insert pipe 9 of the connecting fitting 3 into the connection port of the maintenance valve and fixing it with a sleeve 19 or the like to connect the connecting fitting 3 to the maintenance valve, and by attaching a nozzle removed from, for example, a fire extinguishing hose to the instrument connection fitting 7.

[0008] In a water discharge pressure test, it is necessary to measure the water discharge pressure after the water discharge pressure test device 33 has been made to produce a pressure loss equivalent to that when water is discharged from the fire hose of a fire hydrant system. However, conventional test hoses 5 are only about 1.5m long, which is shorter than the fire hoses (30m) used in fire hydrant systems, so the pressure loss in the hose section is small.

[0009] Therefore, in the conventional water discharge pressure testing device 33, this difference in pressure loss is adjusted at the connecting joint 3. In other words, the device is configured so that the sum of the pressure loss at the connecting joint 3 and the pressure loss at the test hose 5 is equivalent to the pressure loss at the fire extinguishing hose.

[0010] As shown in Figures 5 and 6, the conventional connecting fitting 3 consists of an insert pipe 9 inserted into the connection port 21 of the maintenance valve, a socket base 35 connected to the secondary side of the insert pipe 9, an orifice 13 for adjusting pressure loss, and a component (socket 15, sleeve 19, etc.) for fixing the connecting fitting 3 to the maintenance valve.

[0011] The orifice 13 is a ring-shaped member with an opening in the center, and is provided between the insert tube 9 and the socket base 35. By making the inner diameter of the orifice 13 smaller than the inner diameter of the insert pipe 9, the flow path of the fire extinguishing water is reduced in diameter, which increases the pressure loss at the connecting joint 3. Therefore, the inner diameter of the orifice 13 is set so that a predetermined pressure loss occurs throughout the connecting joint 3, that is, to compensate for the difference in pressure loss between the test hose 5 and the fire extinguishing hose. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2010-42276 [Overview of the project] [Problems that the invention aims to solve]

[0013] As described above, in the water discharge pressure test of a fire hydrant system using the water discharge pressure test device 33, water is discharged using the test hose 5 of the water discharge pressure test device 33. However, as previously mentioned, the length of the test hose 5 is about 1.5m, so depending on the location where the fire hydrant system is installed, the tip of the test hose 5 may not reach the drain outlet during the test, and it may be necessary to discharge water onto the road surface. Therefore, there was a request at the site to increase the length of the test hose 5 to, for example, 5m or 10m.

[0014] As mentioned above, the pressure loss in the water discharge pressure test device 33 is adjusted so that the sum of the pressure loss in the test hose 5 and the pressure loss in the connecting fitting 3 is equivalent to the pressure loss of the fire extinguishing hose. The pressure loss in the connecting fitting 3 is the sum of the pressure losses occurring in the insert pipe 9, the orifice 13, and the socket base 35.

[0015] Therefore, if the length of the test hose 5 is increased, the pressure loss in the test hose 5 will increase, so it is necessary to adjust the pressure loss on the connecting fitting 3 side to reduce it. The pressure loss of the connecting fitting 3 is adjusted by adjusting the inner diameter of the orifice 13 shown in Figure 5. To reduce the pressure loss of the connecting fitting 3, it is best to increase the inner diameter of the orifice 13. However, even if the inner diameter of the orifice 13 is increased, it can only be increased to the same diameter as the inner diameter of the insert tube 9. Increasing the inner diameter beyond that will not reduce the pressure loss. Furthermore, in conventional products, due to changes in the specifications of the fire hydrant system (such as improvements to the fire hose), the inner diameter of the orifice 13 is already almost the same as the inner diameter of the insert pipe 9. As a result, there is virtually no pressure loss added by the orifice 13, and the sum of the pressure losses of the insert pipe 9 and the socket base 35 constitutes the pressure loss of the connecting fitting 3.

[0016] The internal flow path of the socket base 35 has a section where the diameter rapidly increases toward the secondary side (see section A in Figure 5), causing turbulence in the water flow and resulting in a large pressure loss. Therefore, even if the inner diameter of the orifice 13 is maximized (the same diameter as the inner diameter of the insert pipe 9), the pressure loss of the connecting fitting 3 cannot be reduced enough to allow the length of the test hose 5 to be the length requested by the site.

[0017] As described above, with the conventional water discharge pressure testing device 33, it is difficult to reduce pressure loss using the orifice 13, and the pressure loss in the socket base 35 is also large, so it was not possible to meet the on-site demand for a longer test hose 5.

[0018] The present invention has been made to solve the above-described problems, and an object thereof is to provide a fire hydrant device water pressure test apparatus that can reduce the pressure loss on the connection joint side and increase the length of the test hose compared to the prior art.

Means for Solving the Problems

[0019] (1) The fire hydrant device water pressure test apparatus according to the present invention is connected to a maintenance valve of a fire hydrant device and is for testing the water pressure of the fire hydrant device, comprising a connection joint connected to the maintenance valve and a test hose connected to the connection joint, wherein the connection joint has an insert tube inserted into a connection port of the maintenance valve, an orifice provided on the secondary side of the insert tube, a socket base connected to the insert tube via the orifice, and a hose joint provided on the secondary side of the socket base to which the test hose is connected. The socket base has a tapered flow path that expands in diameter from the insert tube side toward the test hose side, and the taper angle of the flow path is 60° or less.

Effects of the Invention

[0020] In the present invention, the flow path formed inside the socket base is tapered to expand in diameter from the insert tube side toward the test hose side, and the taper angle of this flow path is 60° or less, whereby the pressure loss generated in the connection joint can be reduced compared to the prior art. As a result, the length of the test hose connected to the secondary side of the connection joint can be increased compared to the prior art, and the workability of the water pressure test is improved.

Brief Description of the Drawings

[0021] [Figure 1] It is a diagram showing the overall configuration of the water pressure test apparatus according to the embodiment. [Figure 2]Figure 1 shows the connection fittings in the water discharge pressure testing apparatus, illustrating the state before connection to the maintenance valve. [Figure 3] Figure 1 shows the connection fittings in the water discharge pressure testing apparatus, illustrating the state when connected to the maintenance valve. [Figure 4] This diagram shows the overall configuration of a conventional water discharge pressure testing apparatus. [Figure 5] Figure 4 shows the connection fittings in a conventional water discharge pressure testing device, illustrating the state before connection to the maintenance valve. [Figure 6] Figure 4 shows a connecting joint in a conventional water discharge pressure testing device, illustrating the state when connected to a maintenance valve. [Modes for carrying out the invention]

[0022] Figure 1 shows a fire hydrant system water discharge pressure testing device 1 (hereinafter simply referred to as the water discharge pressure testing device 1) according to one embodiment of the present invention. The water discharge pressure testing device 1 is a device for testing the water discharge pressure of a fire hydrant system installed in a tunnel or the like, and is used by connecting it to the maintenance valve of the fire hydrant system. The fire hydrant system (not shown) to be tested by the water discharge pressure test device 1 includes valves such as pressure regulating valves and fire hydrant valves, maintenance valves provided on the secondary side of the valves, and fire hoses provided on the secondary side of the maintenance valves. The maintenance valve is, for example, a three-way switching valve, equipped with a connection port for a fire extinguishing hose and a connection port for the water discharge pressure test device 1. Normally, the connection port for the fire extinguishing hose is open and the connection port for the water discharge pressure test device 1 is closed. During a water discharge pressure test, the secondary flow path of the maintenance valve can be switched from the fire extinguishing hose side to the water discharge pressure test device 1 side by connecting the water discharge pressure test device 1 to the connection port for the water discharge pressure test device.

[0023] As shown in Figure 1, the water discharge pressure test device 1 of this embodiment includes a connecting joint 3 connected to the maintenance valve of a fire hydrant system, a test hose 5 provided on the secondary side of the connecting joint 3, and an instrument connection fitting 7 provided on the secondary side of the test hose 5. The following provides a detailed explanation of each component.

[0024] <Connecting fittings> Figure 2 illustrates the connecting joint 3, with the upper half showing the axial cross-section and the lower half showing the external appearance. As shown in Figure 2, the connecting fitting 3 comprises an insert pipe 9 inserted into the connection port of the maintenance valve, a socket base 11 connected to the secondary side of the insert pipe 9, an orifice 13 provided between the insert pipe 9 and the socket base 11, and a hose fitting 29 (see Figure 1) provided on the secondary side of the socket base 11 to which the test hose 5 is connected. These components form a flow path for fire extinguishing water.

[0025] Furthermore, components such as a socket 15, a collar 17, and a sleeve 19 are provided on the outer circumference of the insert tube 9 as a configuration for fixing the connecting fitting 3 to the maintenance valve. During testing, as shown by the dashed line in Figure 3, the insert tube 9 is inserted into the connection port 21 of the maintenance valve, and the connection port 21 is inserted between the insert tube 9 and the sleeve 19. As a result, the collar 17 provided between the insert tube 9 and the sleeve 19 is pushed towards the socket base 11 against the biasing force of the collar spring 23, and the ball 25, having lost support from the collar 17, fits into a recess provided on the outer surface of the connection port 21. When the ball 25 fits into the recess of the connection port 21, the sleeve 19 slides due to the biasing force of the sleeve spring 27, covering the ball 25 from the outer circumference and maintaining the ball 25 in the recess of the connection port 21, thereby fixing the connecting joint 3 to the maintenance valve.

[0026] Multiple openings 9a are formed at the tip of the insert pipe 9. When fire extinguishing water is supplied to the maintenance valve, the fire extinguishing water flows into the insert pipe 9 through the openings 9a located inside the maintenance valve.

[0027] A socket base 11 is connected to the secondary side of the insert tube 9, and an orifice 13 is provided between the insert tube 9 and the socket base 11. The orifice 13 is a ring-shaped plate with an opening in the center, and the pressure loss occurring in the connecting joint 3 can be adjusted by changing the diameter of the opening, i.e., the inner diameter of the orifice 13. Specifically, by making the inner diameter of the orifice 13 smaller than the inner diameter of the insert pipe 9, the flow path of the fire extinguishing water can be narrowed, and the pressure loss in the connecting joint 3 can be increased.

[0028] The socket base 11 supports the socket 15 and is a component that connects the insert pipe 9 and the hose fitting 29 (see Figure 1). The insert pipe 9 is designed to match the diameter of the connection port 21 of the maintenance valve, while the hose fitting 29 is designed to match the diameter of a test hose, which is the same diameter as a fire extinguishing hose. Generally, the inner diameter of the insert pipe 9 is smaller than the inner diameter of the hose fitting 29.

[0029] Therefore, the flow path formed inside the socket base 11, which is the component connecting these, is tapered, expanding in diameter from the insert pipe 9 side towards the hose fitting 29 side (test hose 5 side). In this embodiment, the taper angle θ of this flow path is set to 10°. Furthermore, the taper angle θ in this invention is not limited to the above; it is acceptable as long as it is 60° or less. As will be explained in more detail later, by making the taper angle θ of the flow path formed inside the socket base 11 60° or less, the pressure loss occurring in the socket base 11 can be reduced compared to conventional methods. This reduces the pressure loss occurring in the connecting fitting 3 compared to conventional methods. It is known that pressure loss is minimized when the taper angle θ is 15° or less. Therefore, a more preferable taper angle θ is 15° or less.

[0030] <Test hose> The test hose 5 is a shape-retaining hose designed to have approximately the same diameter as the fire extinguishing hose of the fire hydrant system under test. As shown in Figure 1, one end is connected to the socket base 11 and the other end to the instrument connection fitting 7 via a hose connector 29. As described above, in this embodiment, the pressure loss occurring in the connecting joint 3 can be reduced compared to conventional designs, making it possible to increase the length of the test hose 5 compared to conventional designs. While the length of the test hose 5 was conventionally about 1.5m, in this embodiment, test hoses 5 of lengths such as 5m or 10m can also be used.

[0031] <Instrument connection fittings> The instrument connection fitting 7 is a component connected to the secondary side of the test hose 5 via a hose connector 29, and is equipped with a pressure gauge 31 capable of measuring the pressure of the fire extinguishing water flowing through it. The instrument connection fitting 7 is also designed to accommodate a nozzle (not shown) that is appropriately selected according to the type of nozzle of the fire hydrant system to be inspected. The nozzle connected to the fire hydrant system being tested is relocated and attached to the instrument connection fitting 7.

[0032] In the water discharge pressure test, with the nozzle attached to the instrument connection fitting 7, fire extinguishing water is passed from the fire hydrant valve to the maintenance valve, and the pressure of the fire extinguishing water supplied from the maintenance valve to the nozzle via the connecting joint 3, test hose 5, and instrument connection fitting 7 is measured with a pressure gauge 31. Based on this measurement, the pressure regulating valve of the fire hydrant system is adjusted if necessary.

[0033] Next, the operation of the water discharge pressure testing apparatus 1 of this embodiment, configured as described above, will be explained. As mentioned above, the socket base 11 of the connecting fitting 3 is a component that connects the insert pipe 9 and the hose fitting 29, which have different inner diameters. Therefore, the flow path inside it is formed in a tapered shape, with the diameter increasing from the insert pipe 9 side to the hose fitting 29 side. In this respect, the socket base 35 of the conventional water discharge pressure testing device 33 is similar, but as shown in Figure 5, the conventional socket base 35 has a large taper angle (see part A in Figure 5), which causes the flow path to rapidly expand, resulting in turbulence in the water flow and a large pressure loss.

[0034] In contrast, as explained in Figure 2, the socket base 11 of this embodiment has a taper angle θ of 60° or less for the internal flow path, resulting in a so-called reducer-shaped flow path where the diameter gradually increases toward the secondary side. By making the flow path inside the socket base 11 a reducer shape in this way, turbulence in the water flow is less likely to occur, and the pressure loss generated in the socket base 11 can be reduced compared to conventional designs.

[0035] The reason why the taper angle θ of the flow path inside the socket base is set to 60° or less in this invention is as follows. First, the fluid head loss when the shape of the flow path changes can be calculated using the following equation (1) with the loss coefficient ζ. h=ζ(ν 2 (2g) ... (1) Here, h is the head loss (m), ζ is the loss coefficient, ν is the small-diameter flow velocity (m / s), and g is the acceleration due to gravity (m / s). 2 ) The head loss h is the pressure loss expressed in terms of head pressure.

[0036] The loss coefficient ζ when the flow path expands gradually can be calculated using the following equation (2). ζ=ε(1-(A1 / A2)) 2 ...(2) Here, A1 is the cross-sectional area of ​​the small diameter portion (mm²). 2 ), A2 is the cross-sectional area of ​​the large diameter part (mm 2 )

[0037] In equation (2), ε is a coefficient that changes with the taper angle θ. The value of the coefficient ε also changes depending on the cross-sectional shape of the pipe and the cross-sectional area ratio A1 / A2, but it is generally found to be smallest when the taper angle θ is between 0° and 15°, and when the taper angle θ is between 15° and 60°, the value of ε increases as the taper angle θ increases, and when the taper angle θ is between 60° and 180°, the value hardly changes even when the taper angle θ increases.

[0038] In other words, in order to reduce the coefficient ε, the taper angle θ must be 60° or less, which allows us to reduce the loss coefficient ζ and, consequently, the pressure loss. Furthermore, as mentioned above, pressure loss is minimized when the taper angle θ is 15° or less. Therefore, to maximize the pressure loss reduction effect in this invention, it is best to set the taper angle θ to 15° or less.

[0039] As described above, in this embodiment, the pressure loss occurring in the socket base 11 can be reduced, so longer test hoses that could not be used with the conventional socket base 35 can be used. Furthermore, if the pressure loss needs to be increased even after extending the test hose to the required length, this can be adjusted by reducing the orifice diameter.

[0040] While reducing the taper angle θ allows for a longer test hose 5, it also increases the axial length of the socket base 11, potentially leading to increased weight and reduced workability. Therefore, it is desirable to set the taper angle θ while considering the balance between the length of the test hose 5 and the length of the socket base.

[0041] Furthermore, since the orifice 13 can be manufactured at a lower cost than the socket base 11, if, for example, the length of the test hose 5 is to be selectable as a product variation, it is preferable to use a common socket base 11 for each product and change the orifice 13 as appropriate. A specific example of this is described below.

[0042] Here, as an example, we will manufacture two types of water discharge pressure testing apparatus 1: one equipped with a 5m long test hose 5 (hereinafter referred to as the 5m product) and another equipped with a 10m long test hose 5 (hereinafter referred to as the 10m product). First, the taper angle θ of the socket base 11 is designed based on the 10m product, which has a larger pressure loss in the test hose 5, i.e., the product that requires a smaller pressure loss at the connecting fitting 3. Furthermore, if no further pressure loss adjustment is required using the socket base 11 described above, the inner diameter of the orifice 13 used in the 10m product is set to be the same diameter as the insert pipe 9. In this case, the orifice 13 does not contribute to pressure loss adjustment and is simply placed as a spacer.

[0043] Alternatively, the taper angle θ of the socket base 11 may be designed to be smaller in order to accommodate future changes in the specifications of the test hose 5 or the fire hydrant system. In this case, the inner diameter of the orifice 13 is made smaller than that of the insert pipe 9 to produce the desired pressure loss. This way, even if it becomes necessary to further reduce the pressure loss in the connecting fitting 3 due to a change in the specifications of the test hose 5, etc., it is not always necessary to change the specifications of the socket base 11, and it may be possible to address this by changing only the specifications of the orifice 13.

[0044] On the other hand, since the 5m product has less pressure loss in the test hose 5 compared to the 10m product, the pressure loss in the connecting fitting 3 needs to be greater than that of the 10m product. Here, for the 5m product, it is advisable to use the same socket base 11 as the 10m product and only change the specifications of the orifice 13. Specifically, it is advisable to use an orifice 13 with a smaller inner diameter than the orifice 13 used in the 10m product, thereby adjusting it to increase the pressure loss in the connecting fitting 3. Thus, when manufacturing multiple types of test hoses 5 with different lengths, it is not always necessary to manufacture a socket base 11 with a different taper angle θ for each product. Manufacturing costs can be reduced by simply changing the specifications of the orifice 13. Furthermore, by further reducing the inner diameter of the orifice 13, it is possible to use a test hose 5, which is approximately 1.5m long and was used in conventional products, as a product variation.

[0045] As described above, in this embodiment, the fire extinguishing water flow path formed inside the socket base 11 has a reducer shape with a taper angle θ set to 60° or less, which makes it possible to reduce the lower limit of the pressure loss that can be adjusted with the connecting fitting 3 compared to conventional methods. This allows the length of the test hose 5 to be increased compared to conventional methods, improving the workability of the water discharge pressure test. [Explanation of Symbols]

[0046] 1. (Fire hydrant system) water discharge pressure testing device 3. Connecting fittings 5. Test hose 7 Instrument connection fittings 9 Insert tubes 9a opening 11 Socket base 13 Orifice 15 sockets 17 colors 19 sleeves 21 connection ports 23 Color Spring 25 balls 27 Sleeve Spring 29 Hose fittings 31 Pressure gauge 33. (Fire hydrant system) water discharge pressure testing device (conventional example) 35 Socket base (conventional example)

Claims

[Claim 1] A fire hydrant discharge pressure testing device connected to the maintenance valve of a fire hydrant system for testing the discharge pressure of the said fire hydrant system, The system comprises a connecting fitting connected to the maintenance valve and a test hose connected to the connecting fitting, The connecting joint comprises an insert tube inserted into the connection port of the maintenance valve, an orifice provided on the secondary side of the insert tube, a socket base connected to the insert tube via the orifice, and a hose fitting provided on the secondary side of the socket base to which the test hose is connected. The fire hydrant water discharge pressure testing device is characterized in that the socket base has a tapered flow path that expands in diameter from the insert pipe side toward the test hose side, and the taper angle of the flow path is 60° or less.

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