Water supply system and its check valve

Abstract

To reduce, not only a space required for a device, but also water supply loss in a flow path.SOLUTION: A housing 101A comprises: pumps (first pump, second pump) that boost a pressure of flowing water; and check valves (first check valve, second check valve) that are connected to flow paths of the pumps, form flow paths in a horizontal direction and a vertical direction continuing to the horizontal direction, and have a pipe 402A in which a check valve cartridge 401, which is a backflow prevention mechanism, is arranged in the flow paths. The check valves have a structure in which the check valve cartridge 401 is provided in the horizontal flow path relative to the pipe 402A on the flow paths, and the horizontal flow path is bent back from the rear of the check valve cartridge 401 to form the vertical flow path in an approximately S-shape.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a water supply device and a check valve thereof.

Background Art

[0002] Conventionally, there is a directly-connected pressurized water supply device in which components such as a pump device equipped with a motor, valves, pipes, an accumulator, and a control panel are housed in a housing portion composed of a pedestal and a drip-proof pump cover.

[0003] As this type of water supply device, generally, a configuration is known in which a check valve is arranged between the discharge port of each pump device and the discharge-side joining pipe so that the fluid pressurized by the other pump in operation does not flow backward (for example, Patent Document 1).

[0004] In the case of such a water supply device, since the device body is installed in various environments such as outdoors, a pump room, and a space under a staircase, generally, weather resistance against the natural environment and space saving from the installation environment are achieved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the other hand, due to the recent increase in electricity prices and the growing need for environmental response such as carbon neutrality, it is necessary to achieve both low loss and high efficiency in water supply. In the case of Patent Document 1, since the connecting pipe structure is curved so that the flow path forms an inverted L shape and extends downward, the flowing water is directly dropped downward. Furthermore, since the connecting pipe structure has a shape that protrudes horizontally in an inverted L shape, it is difficult to save space in the device body, and loss in water supply is a concern.

[0007] Therefore, the present invention has been made in view of the above-mentioned background, and aims to provide a water supply device and its check valve that can reduce not only the overall space of the device but also the water supply loss in the flow path. [Means for solving the problem]

[0008] One embodiment of the water supply device of the present invention, which solves the above problems, is a water supply device comprising: a housing; a pump installed in the housing for pressurizing flowing water; and a check valve installed in the housing, which has a backflow prevention mechanism installed downstream of the pump to form a horizontal flow path and a vertical flow path continuing from the horizontal flow path to prevent backflow of flowing water, wherein the check valve is characterized in that the backflow prevention mechanism is placed in the horizontal flow path, a horizontal return is provided downstream of the backflow prevention mechanism, and a flow path extending vertically from the return is formed.

[0009] Furthermore, one embodiment of the check valve for a water supply device of the present invention is a check valve for a water supply device having a pump, characterized in that a backflow prevention mechanism is arranged in a horizontal flow path downstream of the pump, a horizontal return is provided downstream of the backflow prevention mechanism, and a flow path extending vertically from the return is formed. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a water supply device and its check valve that can reduce not only the overall space of the device but also the water supply loss in the flow path. [Brief explanation of the drawing]

[0011] [Figure 1] This is a front view showing a water supply device according to Embodiment 1 to which the present invention is applied. [Figure 2] This is a three-view drawing showing a check valve in a water supply device according to Embodiment 1 to which the present invention is applied. [Figure 3] This is a side cross-sectional view showing a side view of a check valve according to Embodiment 1 to which the present invention is applied. [Figure 4]This is a cross-sectional view showing the flow direction of the piping in a check valve according to Embodiment 1 to which the present invention is applied. [Figure 5] This is an explanatory diagram illustrating the reduction in losses by the water supply system according to this embodiment 1. [Figure 6] This is a three-view drawing showing a check valve in a water supply device according to Embodiment 2 to which the present invention is applied. [Figure 7] This is a side cross-sectional view showing the side of a check valve in a water supply device according to Embodiment 2 to which the present invention is applied. [Figure 8] This is a three-view drawing showing a check valve in a water supply device according to Embodiment 3 to which the present invention is applied. [Figure 9] This is a side cross-sectional view showing the side of a check valve in a water supply device according to Embodiment 3 to which the present invention is applied. [Figure 10] This is a cross-sectional view showing the air vent hole of a check valve according to Embodiment 3 to which the present invention is applied. [Figure 11] This is a three-view drawing showing a check valve in a water supply device according to Embodiment 3 to which the present invention is applied. [Figure 12] This is a side cross-sectional view showing the side of a check valve in a water supply device according to Embodiment 4 to which the present invention is applied. [Figure 13] This is a cross-sectional view showing the air vent hole of a check valve according to Embodiment 4 to which the present invention is applied. [Figure 14] This is a three-view drawing showing a check valve in a water supply device according to Embodiment 5, to which the present invention is applied. [Figure 15] This is a side cross-sectional view showing the side of a check valve in a water supply device according to Embodiment 5 to which the present invention is applied. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description and drawings are merely examples for explaining the present invention, and for clarity of explanation, appropriate omissions and simplifications have been made. Further, the present invention can be implemented in various other forms. Also, in each embodiment of the present invention, as will be described later, a No. 1 check valve and a No. 2 check valve are provided as components, and when referring to a check valve, it refers to the No. 1 check valve and the No. 2 check valve of each embodiment. Embodiment 1

[0013] Hereinafter, a water supply device provided with a check valve according to Embodiment 1 of the present invention will be described with reference to FIG. 1. FIG. 1 is a front view showing the water supply device according to this Embodiment 1. For simplicity of explanation, the front door is not shown. In the water supply device 101, each unit for supplying water is arranged in its housing 101A.

[0014] In this Embodiment 1, since the check valves (No. 1 check valve 111A, No. 2 check valve 112A) are important components, the description will focus on the check valves installed in the housing 101A at the downstream of the pumps (No. 1 pump 106, No. 2 pump 107) in the water supply flow path. Therefore, detailed descriptions of other parts in the housing 101A other than the No. 1 check valve 111A and the No. 2 check valve 112A will be omitted.

[0015] First, each unit arranged in the housing 101A will be briefly described. The water supply device 101 is composed of, for example, as shown in FIG. 1, a housing frame (pump housing) 102 that supports the entire device, a control frame 104 installed on the housing frame 102 and housing the control unit 103, a unit section 105 that is a unit device housed in the housing frame 102, a control unit 103 that controls the devices of the unit section 105 such as pumps, and the like.

[0016] The unit 105 includes a No. 1 pump 106, a No. 2 pump 107, a pressure reducing backflow preventer 108, a pressure tank 109, a bypass pipe 110, a No. 1 check valve 111A, a No. 2 check valve 112A, a suction gate valve 113 (suction direction 113a), a discharge bend pipe 114 (discharge direction 114a), a suction pressure sensor 115, a discharge pressure sensor 116, a suction confluence pipe 201, a discharge confluence pipe 301, and the like.

[0017] In the example shown in Figure 1, there are two pumps, such as pump 106 and pump 2107, but at least one pump may be used. In the unit 105, the internal fluid flows from the suction shut-off valve 113 to the pressure reducing backflow preventer 108, the suction confluence pipe 201, pump 106 or pump 2107, check valve 111A or check valve 212A, discharge confluence pipe 301, and discharge bend pipe 114. Here, when the inflow pressure is sufficiently high, the fluid is supplied to the customer via the bypass pipe 110 without passing through the pumps (pump 106 and pump 2107).

[0018] The control unit 103 is housed in a control frame 104 installed on top of the housing frame 102 and mainly contains a ground fault circuit breaker, inverter, control board, and other electronic equipment. In the water supply device 101, pressure values ​​obtained from the suction pressure sensor 115 and the discharge pressure sensor 116 are input to the control board, and the inverter is controlled to operate the pump at a variable speed.

[0019] One end of the suction confluence pipe 201 is connected to a pressure-reducing backflow preventer 108. The pressure-reducing backflow preventer 108 is installed between the suction confluence pipe 201 and the suction gate valve 113. The pressure-reducing backflow preventer 108 has the function of restricting the direction of liquid flow in the flow path to one direction. A relief valve section 117 is provided at the bottom of the pressure-reducing backflow preventer 108.

[0020] The relief valve section 117 extends downward from the pressure-reducing backflow preventer 108. A leak detection electrode may be provided at the drain port at the lower tip of the relief valve section 117. The leak detection electrode detects water leakage from the pressure-reducing backflow preventer 108. The detected leak signal can be sent to a leak detection board.

[0021] The suction confluence pipe 201 is connected to the secondary side of the pressure reducing backflow preventer 108. The suction confluence pipe 201 is positioned horizontally below, for example, two pumps 106 and 207. The suction confluence pipe 201 is connected to pump 106 and pump 207, respectively, via suction-side lift valves.

[0022] Specifically, the suction confluence pipe 201 has vertically positioned pumps and integrally includes upward-extending openings 204 and 205. Suction-side lift valves are positioned at the nodes where the central axis of the openings intersects with the horizontal axis of the suction pipe 201. The lower parts of the suction-side lift valves, where the openings 204 and 205 face each other, are removable during assembly and maintenance.

[0023] The first check valve 111A and the second check valve 112A each have one end connected to the pump discharge ports 122 and 123 located on the side walls of the first pump 106 and the second pump 107, respectively. The first check valve 111A and the second check valve 112A have piping 402A that extends forward (horizontally) from the pump discharge ports 122 and 123, respectively, and then bends downward (vertically) in the flow path. The lower ends of the first check valve 111A and the second check valve 112A in the flow path are each connected to a discharge junction pipe 301 located below via a discharge-side lift valve.

[0024] Specifically, as shown in Figure 1, the discharge confluence pipe 301 has two integrated discharge openings, No. 1 discharge opening 304 and No. 2 discharge opening 305, which extend upward in order to connect with the primary check valve 111A and secondary check valve 112A, which are arranged vertically. A discharge-side lift valve is positioned at the node where the central axis of the opening of this discharge confluence pipe 301 intersects with the horizontal axis of the suction confluence pipe 201.

[0025] The lower parts of the No. 1 suction-side lift valves and No. 2 suction-side lift valves on opposite sides of the No. 1 discharge opening 304 and No. 2 discharge opening 305 are removable during assembly and maintenance. In addition, the lower part of each discharge-side lift valve is connected to the discharge bend pipe 114, which carries the liquid that has flowed into the discharge-side confluence pipe 301. Opening and closing the lift valve body controls water flow, shut-off, and changes in flow direction.

[0026] The suction confluence pipe 201 and the discharge confluence pipe 301 each have downward-extending openings, bypass connection sections 206 and 306, in their intermediate portions, to which bypass pipes are connected. In addition, a bypass check valve 124 is positioned in the bypass pipe 110 on the side closer to the discharge confluence pipe 301.

[0027] Next, the first check valve 111A and the second check valve 112A will be described in detail using Figures 2, 3, and 4. Figure 2 is a three-view drawing showing the check valve of a water supply system according to Embodiment 1 to which the present invention is applied, Figure 3 is a side cross-sectional view showing the side (direction E) of the check valve according to Embodiment 1 to which the present invention is applied, and Figure 4 is a cross-sectional view showing the cross-section in the flow direction of the piping in the check valve of Embodiment 1 to which the present invention is applied.

[0028] Here, since the No. 1 check valve 111A and the No. 2 check valve 112A have similar configurations, the No. 1 check valve 111A will be described as a representative example. As shown in Figure 2, the No. 1 check valve 111A is shown in (a) as a top view, (b) as a front view, and (c) as a side view (direction E), with the horizontal direction aligned with the center line Ch1 and the vertical direction aligned with the center line Cv1.

[0029] The No. 1 check valve 111A is composed of, for example, a check valve cartridge 401 that is detachable from the check valve body 402, the check valve body 402, a check valve inlet fitting 403, an O-ring 404, and an air vent cock 405. The check valve cartridge 401, which is a backflow prevention mechanism, is equipped with a spring-type valve body 401b and is held horizontally by the check valve body 402.

[0030] In this valve body 401b, by using a spring-type structure instead of a swing-type structure, it is possible to flexibly prevent backflow in response to the force of the flowing water, and also to suppress the occurrence of water hammer, which poses a risk of backflow.

[0031] In this embodiment 1, the check valve cartridge 401, which requires installation space, is installed on the horizontal flow path of the piping 402A. The check valve body 402 has a structure in which it curves back from the subsequent horizontal flow path and connects to the vertical flow path from that bend.

[0032] Furthermore, the main material of the check valve cartridge 401 is POM (Polyoxymethylene) resin, and the sealing portion 401c of the case 401a and valve body 402b is equipped with NBR (Nitril Butadiene Rubber).

[0033] The check valve body 402 includes a holding portion 402a for the check valve cartridge 401 and a roughly S-shaped pipe 402A that discharges the secondary flow of the check valve cartridge 401 and guides it to the confluence pipe 301. Specifically, the No. 1 check valve 111A has a structure in which its pipe 402A is bent so as to fold back in the horizontal direction from the upstream side extending horizontally to the downstream side extending vertically downward, so that the cross-sectional shape in the flow direction is roughly S-shaped.

[0034] The upper half 402b of the bent portion of the secondary flow deflected downward in the check valve cartridge 401 forms a roughly conical flow path centered on the inlet centerline O1 and has a tapered structure.

[0035] As you move downstream from this roughly conical flow path upstream, the water flow area widens, increasing the velocity of the water and allowing it to be output smoothly from the check valve. The shape of the flow path changes from a cross-section in the direction of the semicircular cross-section shown in Figure 3, to a roughly semicircular cross-section in the lower half 402c as shown in Figure 4, gradually connecting to the circularly opening check valve inlet 407.

[0036] The bending center O3 of the check valve body 402 extends to a position opposite the check valve inlet 406 relative to the outlet center O2. A flow path is formed so that the bending center O3 and the outlet center O2 are in smooth communication. In this embodiment, the flow from the lower half of the bending section 402c to the check valve inlet 407 is a decelerated flow with a larger cross-sectional area. That is, in the No. 1 check valve 111A, the piping 402A has a structure in which the inner diameter is increased from the downstream section of a roughly conical structure that tapers in the vertical direction, i.e., in the vertical (downward) flow path.

[0037] The expansion angle 2θ, which is determined from the streamline length and the equivalent circle diameter of the cross-sectional area, which serve as indicators of cross-sectional area expansion, is best set to 8-10°, and should not exceed 20°. Furthermore, the flow from the lower half of the bent section 402c to the check valve inlet 407 may be a velocity-increasing flow with a smaller cross-sectional area, or a constant velocity flow with an equal cross-sectional area.

[0038] The upper half 402b of the bend, which is the highest point in the entire flow path of the water supply system, is equipped with an air vent cock mounting 408 and an air vent cock 405, which are necessary when the pump is in operation. The downstream end of the check valve body 402 is roughly umbrella-shaped so that it can be connected to the discharge confluence pipe 301 with a ferrule.

[0039] Furthermore, the upstream end of the check valve body 402 is equipped with a threaded portion for connecting the check valve inlet fitting 403 to the outer circumference of the cylindrical part that holds the check valve cartridge 401. The check valve inlet fitting 403 guides the flow out from the pump discharge ports 122 and 123 to the check valve cartridge 401 and holds the check valve cartridge 401, which is held in the check valve body 402, in place to prevent it from moving. The O-ring 404 serves to seal the water by being compressed. In this embodiment 1, the cross-sectional area from the cross-section of the check valve inlet fitting 403 to the outlet 409 of the check valve inlet fitting results in an accelerated flow.

[0040] Furthermore, in the case of decelerating flow where the cross-sectional area from the cross-section of the check valve inlet joint 403 to the check valve inlet joint outlet 409 is larger, the expansion angle 2θ, which is calculated from the streamline length (an index of cross-sectional area expansion) and the equivalent circle diameter of the cross-sectional area, is best, for example, 8 to 10°, and should not exceed 20°. The cross-sectional area from the cross-section of the check valve inlet joint 403 to the check valve inlet joint outlet 409 is also equal in the case of constant velocity flow.

[0041] The upstream end of the check valve inlet fitting 403 is roughly umbrella-shaped so that it can be connected to the pump discharge ports 122 and 123 via a ferrule. The downstream end of the check valve inlet fitting 403 is threaded for connection to the check valve body 402 that holds the check valve cartridge 401.

[0042] The check valve body 402 and the check valve inlet fitting 403 are made of CAC911, which exhibits minimal lead leaching when in contact with working fluids such as tap water. Other materials such as stainless steel or materials treated to suppress lead leaching may also be used.

[0043] In the water supply system 101 equipped with the check valve configured as described above, the pumps 106 and 107, which have a pump discharge in the horizontal direction and a rotation axis in the vertical direction, can effectively utilize the space in the height direction by arranging the check valve cartridge 401 horizontally, and the space in the direction of the inlet center O1 can be effectively utilized by making the check valve body 402 roughly S-shaped. Furthermore, a highly efficient water supply system can be obtained that reduces pressure loss by providing a larger check valve volume than conventional systems, despite having the same mounting dimensions as conventional systems.

[0044] Furthermore, by making the check valve part a cartridge, maintenance man-hours and materials used can be minimized in the event of malfunctions due to foreign matter or deterioration over time. The check valve cartridge 401 has a spring-type valve body 401b, so when the pump operation is suddenly stopped due to a power outage or abnormality detection, the valve opening gradually decreases in accordance with the flow rate until it is fully closed, thereby suppressing water hammer.

[0045] The upper half of the bent section 402b is made roughly conical, which suppresses flow separation due to unnecessary area expansion in the secondary flow of the check valve cartridge and reduces losses. The lower half of the bent section 402c has a roughly semicircular cross-sectional shape, which maximizes the flow area within the check valve mounting space, suppresses an increase in flow velocity and reduces friction losses. Furthermore, the expansion angle when flowing down to the check valve inlet 407 is also suppressed, thus reducing expansion losses.

[0046] By using ferrule connections at both ends of the No. 1 and No. 2 check valves 111A and 112A, installation and removal are made easy, improving ease of assembly and maintenance. Furthermore, by using lead-free bronze CAC911 and POM resin as materials, the leaching of harmful substances into the tap water supply is suppressed, improving the reliability of the water supply.

[0047] Here, the reduction of losses by the water supply device of this embodiment 1 will be explained using Figure 5. Figure 5 is a graph illustrating the reduction of losses by the water supply device of this embodiment 1. As shown in Figure 5, the graph shows pressure loss on the vertical axis and flow rate on the horizontal axis, with the solid line showing the pressure loss of a conventional check valve and the dashed line showing the pressure loss of the check valve of embodiment 1 at each flow rate.

[0048] Here, we will use pressure loss as an example to explain the loss. Pressure loss tends to increase with increasing flow rate, but in the case of this embodiment 1, it can be seen that the pressure loss is reduced to 1 / 5 at 100% flow rate compared to the conventional type. Note that this graph is just an example, and the values ​​will differ depending on conditions such as the size of the water supply equipment and check valve, but the significant reduction effect remains the same.

[0049] In this embodiment 1, expressions such as horizontal and vertical directions were used to describe the flow path of the check valve. However, this does not mean that the shape of the check valve body is limited to one that has no inclination whatsoever in the horizontal or vertical direction. Rather, it means that the piping of the check valve body is arranged along the horizontal and vertical directions. Of course, the structure of the check valve may also have piping that is completely horizontal and vertical.

[0050] As described above, according to this embodiment 1, the flow path of the check valve, which proceeds from the primary side to the secondary side, is curved back in a way that folds back in the horizontal direction and descends in the vertical direction, forming a roughly S-shaped piping structure. Therefore, the mounting dimensions of the housing in the horizontal direction can be kept small when connecting the check valve to the housing. As a result, the configuration and arrangement of the check valve suppress interference not only with the housing but also with the frame and other units, making it possible to save space for the entire water supply system 101.

[0051] Furthermore, the check valve is constructed with a roughly S-shaped piping from upstream to downstream of the flow path, while increasing the diameter of the piping, i.e., the flow path area, in the vertical downstream direction. This structure ensures an appropriate flow path area on the secondary side while reducing water supply losses in the flow path. In this way, it is possible to simultaneously achieve space savings and suppress various losses related to water supply.

[0052] Here, we will also explain the individual effects of various loss suppression methods. By positioning the check valve cartridge of this embodiment 1 upstream of the check valve, it becomes possible to enlarge the valve body. As a result, it becomes possible to suppress the pressure of the flowing water. Furthermore, by positioning the check valve cartridge horizontally with respect to the check valve body, the structure of the check valve itself contributes to space saving.

[0053] In this space-saving configuration, the substantially conical shape provided upstream of the check valve prevents unnecessary area expansion in the flow path, thereby suppressing water separation loss. Furthermore, by making the flow path of the check valve substantially S-shaped to secure the flow path area, it is possible to suppress friction loss of the flow. Embodiment 2

[0054] Next, Embodiment 2 of the present invention will be described using Figures 6 and 7. Figure 6 is a three-view drawing showing a check valve in a water supply device according to Embodiment 2 to which the present invention is applied, and Figure 7 is a side cross-sectional view showing the side (direction E) of the check valve in the water supply device according to Embodiment 2 to which the present invention is applied. Hereinafter, the same configuration as in Embodiment 1 will be omitted from description and illustration of reference numerals, and the same numbers will be used in the description.

[0055] Regarding check valves, as representative of check valves No. 1 and No. 2, we will explain using check valve No. 1 111B as an example, as shown in Figure 6. As shown in Figure 6, check valve No. 1 111B is shown with its shape from above (a), its shape from the front (b), and its shape from the side (direction E) (c), with the horizontal direction aligned with the center line Ch2 and the vertical direction aligned with the center line Cv2.

[0056] As shown in Figure 7, the first check valve 111B of this second embodiment has a threaded joint at one downstream end of the check valve body 402, and is configured with an extension adapter 410 between the check valve body 402 and the discharge side confluence pipe 301. The upstream end of the extension adapter 410 has a threaded portion so as to be connected to the check valve body 402 and is equipped with an extension O-ring. The downstream end of the extension adapter 410 is substantially umbrella-shaped so as to be connected to the pump discharge ports 122 and 123 with a ferrule.

[0057] As described above, according to this embodiment 2, the mounting dimensions of the check valve can be easily changed by the configuration equipped with the extension adapter 410 described above. Therefore, even if the pump discharge port height changes due to differences in the number of pump impeller stages according to customer specifications, it can be installed without any problems. In other words, it is possible to flexibly accommodate the specifications (size, etc.) of the pump. In this way, it is no longer necessary to stock various different sizes of check valve bodies, and not only the production efficiency in the manufacturing process but also the number of parts can be reduced. Embodiment 3

[0058] Next, Embodiment 3 of the present invention will be described using Figures 8, 9, and 10. Figure 8 is a three-view drawing showing a check valve in a water supply device according to Embodiment 3 to which the present invention is applied, Figure 9 is a side cross-sectional view showing the side (direction E) of the check valve in a water supply device according to Embodiment 3 to which the present invention is applied, and Figure 10 is a cross-sectional view showing the air vent hole in the check valve according to Embodiment 3 to which the present invention is applied.

[0059] In the following, for configurations similar to those in Embodiment 1, the explanatory reference numerals will not be shown in the illustration, and the same numbers will be used in the explanation. As shown in Figure 8, the check valve No. 1, check valve 111C will be used as an example to explain the check valve No. 1, as shown in Figure 8. The shape of the check valve No. 1, check valve 111C is shown in (a) as viewed from above, (b) as viewed from the front, and (c) as viewed from the side (direction E), with the horizontal direction aligned with the center line Ch3 and the vertical direction aligned with the center line Cv3. Figure 10 shows the cross-sectional shape with respect to the flow path direction.

[0060] As shown in Figure 9, the No. 1 check valve 111C is equipped with an air vent mounting hole 408 and an air vent cock 405 on the side surface of the cylindrical portion that holds the check valve cartridge 401 of the check valve body 402. The air vent cock 405 is provided on the primary side, i.e., the upstream side, rather than on the secondary side, i.e., the downstream side, of the check valve 111C, as it is desirable to vent the air there.

[0061] Furthermore, as shown in Figures 9 and 10, the No. 1 check valve 111C forms an air vent passage 411A between itself and the side wall of the check valve cartridge 401 as a substantially semicircular groove on the side surface of the cylindrical part that communicates with the air vent mounting hole 408 and allows air AR1 to pass through. This creates a passage inside the check valve body 402 for venting air from the pump to the outside. Here, it is described as substantially semicircular, but the cross-sectional shape may be substantially circular, and is not limited to this.

[0062] The surface of the check valve inlet fitting 403 facing the check valve cartridge 401 is provided with, for example, four protrusions. These protrusions create a gap between the check valve cartridge 401 and the fitting, forming a passage that communicates with the air vent passage 411A of the check valve body 402. The check valve cartridge 401 is also provided with a primary side O-ring 404 as a primary side seal and a secondary side O-ring 404 as a secondary side seal.

[0063] As described above, according to this embodiment 3, by forming an air venting passage with a groove provided between the check valve body 402 and the check valve cartridge 401, air can be easily vented from the primary side of the check valve. Therefore, compared to the above-described embodiment 1, the air inside the pump can be discharged in a shorter time and the pump can be filled to a full water state. This can improve the water injection efficiency or priming efficiency. Embodiment 4

[0064] Next, Embodiment 4 of the present invention will be described using Figures 11, 12, and 13. Figure 11 is a three-view drawing showing a check valve in a water supply device according to Embodiment 4 to which the present invention is applied, Figure 12 is a side cross-sectional view showing the side of the check valve in a water supply device according to Embodiment 4 to which the present invention is applied, and Figure 13 is a cross-sectional view showing the air vent hole in the check valve according to Embodiment 4 to which the present invention is applied. Note that Figure 13 shows the cross-sectional shape with respect to the flow path direction.

[0065] In the following, the same configurations as those in Embodiment 1 and Embodiment 3 will not be described, and the same numbers will be used in the description. As representatives of the check valves No. 1 and No. 2, the No. 1 check valve 111D will be described as an example, as shown in Figure 11. As shown in Figure 11, the No. 1 check valve 111D is shown in (a) as viewed from above, (b) as viewed from the front, and (c) as viewed from the side (direction E), with the horizontal direction aligned with the center line Ch4 and the vertical direction aligned with the center line Cv4.

[0066] As shown in Figures 12 and 13, the No. 1 check valve 111D is provided with an air vent mounting hole 408 and an air vent cock 405 on the side surface of the cylindrical portion of the check valve body 402 that holds the check valve cartridge 401. Furthermore, as shown in Figure 13, the side surface of the cylindrical portion of the check valve body 402 is provided with an air vent passage 411B having a substantially circular cross-section, which communicates with the air vent mounting hole 408 and allows air AR2 to pass through. This creates a passage inside the check valve body 402 for extracting air from the pump to the outside. The surface of the check valve inlet fitting 403 facing the check valve cartridge 401 is provided with, for example, four protrusions.

[0067] This protrusion creates a gap between it and the check valve cartridge 401, forming a passage that communicates with the air vent passage 411B of the check valve body 402. In addition, a primary side O-ring 404 is provided as a water seal on the primary side of the check valve cartridge 4011.

[0068] As described above, according to this embodiment 4, by forming an air vent passage in the check valve body itself, air can be vented from the primary side (upstream side) of the check valve. Therefore, compared to embodiment 1, the air inside the pump can be discharged in a shorter time, and the pump can be filled with water. This improves the water injection efficiency or priming efficiency. Furthermore, since the number of water sealing points can be reduced compared to embodiment 3 described above, manufacturability and reliability can be improved. Embodiment 5

[0069] Next, Embodiment 5 of the present invention will be described using Figures 14 and 15. Figure 14 is a three-view drawing showing a check valve in a water supply device according to Embodiment 5 to which the present invention is applied, and Figure 15 is a side cross-sectional view showing a side view of the check valve in a water supply device according to Embodiment 5 to which the present invention is applied. Hereinafter, for configurations similar to those in Embodiment 1, the illustration of explanatory reference numerals will be omitted, and the same numbers will be used in the description. Regarding the check valve, as representatives of check valves No. 1 and No. 2, check valve No. 1 111E will be described as an example, as shown in Figures 14 and 15. As shown in Figure 14, check valve No. 1 111E is shown with its shape from above (a), its shape from the front (b), and its side view (a), its shape from the front (b), and its shape from the side (direction E) (c), with the horizontal direction aligned with the center line Ch5 and the vertical direction aligned with the center line Cv5.

[0070] As shown in Figure 15, one end of the check valve inlet fitting 403 on the pump discharge side is equipped with a boltable flange 500, and one end on the check valve cartridge side is equipped with a threaded portion, similar to Embodiment 1. One end of the check valve body 402 on the discharge confluence pipe side is equipped with a boltable flange 500, and one end on the check valve cartridge side is equipped with a threaded portion, similar to Embodiment 1.

[0071] As described above, according to this embodiment 5, the check valve, like the No. 1 check valve 111E, can be bolted to the flange 500. Therefore, it can be manufactured at a lower cost compared to other embodiments, thus improving economic efficiency. In particular, the fact that the check valve can be replaced, and that the flange 500 makes replacement work easier, is also highly useful.

[0072] Furthermore, according to the embodiments described above, since the valve body is replaceable by a check valve cartridge, it is clear that this contributes not only to the reuse of the check valve itself from the perspective of SDGs (Sustainable Development Goals) but also to a reduction in material costs.

[0073] While preferred embodiments of the present invention have been described and explained above, it should be understood that these are illustrative examples of the invention and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the invention. [Explanation of Symbols]

[0074] 101 Water supply equipment 101A enclosure Pump No. 106 Pump No. 107-2 111A No. 1 Check Valve 111B No. 1 Check Valve 111C No. 1 Check Valve 111D No. 1 Check Valve 111E No. 1 Check Valve 112A No. 2 Check Valve 112B No. 2 Check Valve 112C No. 2 Check Valve 112D No. 2 Check Valve 112E No. 2 Check Valve 122 Pump discharge port 123 Pump discharge port 304 Discharge opening 305 Discharge opening 401 Check valve cartridge 401a case 401b Valve body 401c seal section 402 Check valve body 402a Holding part 402A Piping 402b Upper half of bent part 402c bent lower half 403 Check valve inlet fitting 404 O-ring 405 Air vent valve 406 Check valve inlet 407 Check valve outlet 408 Air vent valve mounting hole 409 Check valve inlet fitting outlet 410 Extension Adapter 411A Air vent channel 411B Air vent channel 500 flange

Claims

1. A water supply device, The casing and A pump installed in the enclosure increases the pressure of the flowing water, A check valve is installed in the housing and has a backflow prevention mechanism installed to form a horizontal flow path and a vertical flow path that continues from the horizontal flow path downstream of the pump, thereby preventing backflow of flowing water in the flow path, Equipped with, The check valve has the backflow prevention mechanism positioned in the horizontal flow path, the horizontal return section provided downstream of the backflow prevention mechanism, and a flow path extending vertically from the return section. The check valve is characterized in that the center of the bend in the flow path extending vertically from the return is located opposite the check valve inlet relative to the outlet center, and the flow path is formed such that the space between the center of the bend and the outlet center is in communication.

2. A water supply device according to Claim 1, characterized in that the check valve is formed in a substantially S-shape in cross-section with respect to the direction of the flow path.

3. A water supply device according to Claim 1, characterized in that the backflow prevention mechanism is of the lift type.

4. The water supply device according to claim 1, wherein the check valve has a substantially conical structure in which the flow area is reduced downstream of the backflow prevention mechanism on the horizontal flow path.

5. The water supply device according to Claim 4, wherein the check valve has a structure in which the water flow area expands from downstream of the substantially conical structure on the vertical flow path.

6. In the water supply device according to claim 5, The upper half of the bent portion in the flow path extending vertically from the aforementioned fold is substantially conical in shape. The lower half of the bent portion is roughly semicircular in shape. Furthermore, the water supply device is characterized in that the portion where the water flow area expands in the downstream portion of the substantially conical shape is in communication with the substantially semicircular flow path.

7. A water supply device according to claim 1, characterized in that a detachable extension adapter is provided between the check valve and the piping downstream of the check valve.

8. A water supply device according to claim 1, characterized in that the check valve has an air passage provided above the backflow prevention mechanism that extends from the pump to the outside.

9. A water supply device according to claim 1, characterized in that a detachable flange is provided at one end of the check valve.

10. A water supply device according to claim 9, characterized in that the backflow prevention mechanism is detachably attached to the check valve.

11. A check valve for a water supply system with a pump, A backflow prevention mechanism is placed in the horizontal flow path downstream of the pump, a horizontal return is provided downstream of the backflow prevention mechanism, and a flow path extending vertically from the return is formed. A check valve for a water supply device, characterized in that the center of the bend in the flow path extending vertically from the aforementioned fold is located opposite the check valve inlet relative to the outlet center, and the flow path is formed such that the space between the center of the bend and the outlet center is in communication.

12. A check valve for a water supply device according to claim 11, characterized in that the cross-section is formed in a substantially S-shape in the flow path direction.

13. A check valve for a water supply device according to claim 11, characterized in that the downstream stage of the backflow prevention mechanism on the horizontal flow path is formed in a substantially conical shape that reduces the flow area.

14. A check valve for a water supply device according to claim 13, characterized in that, on the vertical flow path, the water flow area expands from the downstream of the substantially conical structure.

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