Check valve for water system

Abstract

To provide a check valve for a water supply facility capable of invalidating and restoring a backflow prevention function of the check valve without disassembling and assembling the check valve.SOLUTION: The check valve includes a valving element 31 for opening or closing an 1d of a hole, a valving element pressing portion 32 provided on a side opposite to the 1d of the valving element with respect to the valving element 31, and a biasing member 33 for biasing the valving element 31 toward the valving hole. When the state is shifted from the normal state to the valve opening maintaining state, the valve body pressing portion 32 moves in the approaching direction with respect to the valve hole 1d and engages with the valve body 31, and then the valve body pressing portion 32 and the valve body 31 move in the separating direction with respect to the valve hole 1d, so that the valve body 31 forcibly maintains the valve opening while resisting the urging of the urging member 33.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a check valve for a water supply system that prevents backflow of water from the secondary side to the primary side in the water supply system. [Background technology]

[0002] A check valve is known for use in stop valves and other water supply systems that are installed between the primary and secondary sides of a water supply system. This check valve prevents tap water from flowing back from the secondary side to the primary side.

[0003] For example, as shown in Patent Document 1, a conventional check valve comprises a main body barrel through which a fluid flows, a valve hole formed inside the main body barrel, a valve element that opens and closes the valve hole from the secondary pipe section side, a cap that is provided on the back side of the valve element and covers the valve element, a spring that is supported by the cap and the valve element and urges the valve element toward the valve hole side, and a cylindrical body that houses the cap and spring inside, and the valve element is urged by the spring to close the valve hole. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-215003 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when conducting a water flow test in which water is passed through the secondary side for a pressure test of the pipe, in order to disable the check valve's backflow prevention function, the check valve had to be disassembled and the valve disc removed before the test and then reassembled, and after the test, the check valve had to be disassembled again and the valve disc attached and then reassembled.This not only took time and effort to perform the water flow test, but also posed the problem of dust, dirt, or dirt getting into the device when disassembling and assembling the check valve, and there was also the risk of parts being lost.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a check valve for water supply equipment that can disable and restore the backflow prevention function of the check valve without disassembling or assembling the check valve. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a check valve for waterworks equipment that opens a valve hole in the waterworks equipment to allow water to flow from the primary side to the secondary side, and closes the valve hole to prevent backflow of water from the secondary side to the primary side, and is equipped with a valve body that opens or closes the valve hole, a valve body pressing part provided on the opposite side of the valve hole from the valve body, and a biasing member that biases the valve body toward the valve hole, and has two states: a normal state in which the valve body is biased by the biasing member to open or close in response to water pressure from the primary side to the secondary side, and a reverse state in which the valve body is not biased against the biasing member. The valve body has at least an open valve maintaining state in which the valve body is forcibly kept open while remaining closed, and when transitioning from the normal state to the open valve maintaining state, the valve body holding portion moves in a direction approaching the valve hole and engages with the valve body, and then the engaged valve body holding portion and the valve body move in a direction away from the valve hole, thereby forcibly keeping the valve open against the bias of the biasing member, while when transitioning from the open valve maintaining state to the normal state, the engagement between the valve body and the valve body holding portion is released, so that the valve body is biased by the biasing member to close.

[0008] According to this, when transitioning from the normal state to the valve-open maintaining state, the valve disc holder moves toward the valve orifice and engages with the valve disc, and then the engaged valve disc holder and the valve disc move away from the valve orifice, forcibly maintaining the valve open against the biasing force of the biasing member, so that transition from the normal state to the valve-open maintaining state is made possible by the simple operation of engaging the valve disc with the valve disc holder. Also, when transitioning from the valve-open maintaining state to the normal state, the engagement between the valve disc holder and the valve disc is released, so that the valve disc closes while being biased by the biasing member, so that transition from the normal state to the valve-open maintaining state is made possible by the simple operation of releasing the engagement between the valve disc and the valve disc holder.

[0009] The valve may be provided with an engaging protrusion or an engaging recess that can engage with the valve disc holding portion, and the valve disc holding portion may be provided with an engaging protrusion or an engaging recess that can engage with the valve, so that when the valve disc holding portion moves in a direction approaching the valve hole, the engaging protrusions of the valve and the valve disc holding portion or the engaging protrusion and the engaging recess can engage with each other. This allows the valve and the valve disc holding portion to engage with each other using a simple configuration.

[0010] The valve element may have a support portion extending toward the valve element holder portion, and the support portion may be provided with an engaging protrusion or an engaging recess that engages with the valve element holder portion. This allows the valve element and the valve element holder portion to be stably engaged with each other using a simple structure.

[0011] The valve disc retainer may have a support portion extending toward the valve disc, and the support portion may be provided with the engaging protrusion or the engaging recess that engages with the valve disc. This allows for a more stable engagement between the valve disc and the valve disc retainer with an even simpler configuration.

[0012] Furthermore, a restricting portion may be provided that restricts movement of the valve disc in a direction away from the valve hole, and when transitioning from the valve-open maintaining state to the normal state, movement of the valve disc in the direction away from the valve hole is restricted by the restricting portion, and the engagement between the valve disc and the valve disc retaining portion is released by moving only the valve disc retaining portion in the direction away from the valve hole. In this way, when transitioning from the valve-open maintaining state to the normal state, the engagement between the valve disc retaining portion and the valve disc can be released simply by moving the valve disc retaining portion in the direction away from the valve hole.

[0013] Furthermore, a plug rod may be provided which is threadably connected to the valve disc holder, and the plug rod rotates axially in a forward direction to move the valve disc holder toward the valve hole, while the plug rod rotates axially in a reverse direction to move the valve disc holder away from the valve hole. This allows the valve disc holder to be moved toward or away from the valve hole with a simple configuration.

[0014] The present invention also provides a stop valve equipped with the above-described check valve for water supply equipment. [Effects of the Invention]

[0015] According to the present invention, when transitioning from the normal state to the valve-open-maintaining state, the valve disc holder moves toward the valve orifice to engage with the valve disc, and then the engaged valve disc holder and the valve disc move away from the valve orifice, forcibly maintaining the valve disc open, allowing transition from the normal state to the valve-open-maintaining state by the simple operation of engaging the valve disc with the valve disc holder. Also, when transitioning from the valve-open-maintaining state to the normal state, the engagement between the valve disc holder and the valve disc is released, causing the valve disc to close in a manner biased by the biasing member, allowing transition from the valve-open-maintaining state to the normal state by the simple operation of releasing the engagement between the valve disc and the valve disc holder.

[0016] This allows the backflow prevention function of the check valve to be disabled and restored without disassembling or assembling the check valve, which significantly reduces the time and effort required for water flow tests, and also prevents dust, dirt, and other contaminants from getting into the device and prevents parts from being lost. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing the overall configuration of a stop valve having a check valve according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the stop valve of FIG. 1. [Figure 3] FIG. 2 is an exploded view of the check valve in the stop valve of FIG. [Figure 4] 1. FIG. 4 is a diagram showing a process in which the check valve in the stop valve of FIG. 1 shifts from a normal state to a valve-open state (partway through). [Figure 5] 1. FIG. 6 is a diagram showing a second process in which the check valve in the stop valve of FIG. 1 further shifts from the open valve maintaining state (intermediate) to the open valve maintaining state (final). [Figure 6] 1. FIG. 4 is a diagram showing a process in which the check valve in the stop valve of FIG. 1 shifts from the open valve maintaining state (final) to the normal state. [Figure 7] FIG. 4(b) is an enlarged cross-sectional view of part I in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, an embodiment of a stop valve having a check valve according to the present invention will be described with reference to FIGS.

[0019] As shown in Figure 1, this stop valve is installed in a water supply facility and comprises a main body 1, a stop valve 2 installed inside the main body 1, a check valve 3 installed on the secondary side of the stop valve 2, and an expandable pipe 4 installed on the secondary side of the main body 1.

[0020] As shown in FIG. 2, the main body 1 is provided with an inlet 1a that opens to the right on the primary side, an outlet 1b that opens to the left on the secondary side, a partition 1c that divides the interior vertically, a valve hole 1d drilled in the partition 1c, and an opening 1e that opens upward, and by closing the opening 1e with a box body 34 (described later), a valve chamber 1f is formed on the secondary side of the partition 1c.

[0021] As shown in Figures 1 and 2, the stop valve 2 comprises a ball valve body 2a having a two-way or three-way flow path, a secondary plug rod 2b extending from the ball valve body 2a toward the front, a secondary plug rod holder 2c that holds the secondary plug rod 2b from the front side, a cap 2d that covers the secondary plug rod holder 2c, and a lever handle 2e that is provided at the tip of the secondary plug rod 2b and rotates the secondary plug rod 2b about its axis.

[0022] As a result, when the lever handle 2e is rotated in one direction, the ball valve body 2a rotates via the secondary plug rod 2b, and as a result, the ball valve body 2a opens the flow path from the inlet portion 1a to the valve hole 1d, allowing water to pass through. On the other hand, when the lever handle 2e is rotated in the opposite direction, the ball valve body 2a rotates via the secondary plug rod 2b, and as a result, the ball valve body 2a closes the flow path from the inlet portion 1a to the valve hole 1d, stopping the water from passing through.

[0023] As shown in Figures 2 and 3, the check valve 3 comprises a valve element 31 that opens or closes the valve orifice 1d from the secondary side, a valve element holding portion 32 provided on the opposite side of the valve element 31 from the valve orifice 1d, a spring 33 that urges the valve element 31 toward the valve orifice 1d, a box 34 that houses the valve element 31 and valve element holding portion 32, etc., a plug rod 35 connected to the valve element holding portion 32, and a handle 36 provided at the upper end of the plug rod 35. Under normal conditions, the check valve 3 allows water to flow from the primary side to the secondary side by opening the valve orifice 1d, and prevents water from flowing back from the secondary side to the primary side by closing the valve orifice 1d.

[0024] As described above, the check valve 3 has a normal state in which it opens or closes in response to the water pressure from the secondary side to the primary side while being biased by the spring 33, an open state in which it forcibly maintains the valve open while resisting the bias of the spring 33, and a closed state in which it forcibly maintains the valve closed while being biased by the spring 33.

[0025] As shown in Figures 2 and 3, the valve body 31 includes a cylindrical first support portion 31a, a bottom portion 31b that is provided to close the lower portion of the first support portion 31a, a cylindrical second support portion 31d that is provided upright inside the first support portion 31a, and a resin valve body gasket 31e that covers the underside of the bottom portion 31b.

[0026] Furthermore, the valve body 31 moves in an approaching / moving away direction (up / down direction) relative to the valve orifice 1d while maintaining its position relative to the valve orifice 1d by the outer surface of the first support portion 31a sliding on the inner surface 34h of the box body 34. When the valve body 31 moves in an approaching direction (downward) relative to the valve orifice 1d, the valve body packing 31e comes into contact with the partition wall 1c surrounding the valve orifice 1d to close the valve, while when the valve body 31 moves in an away direction (upward) relative to the valve orifice 1d, the valve body packing 31e comes off from the partition wall 1c surrounding the valve orifice 1d to open the valve.

[0027] Furthermore, the valve body 31 has a recess 31f formed between the first support portion 31a and the second support portion 31d, and the lower end portion 33a of the spring 33 is inserted into the recess 31f.

[0028] In addition, the valve body 31 has an engaging protrusion 31g provided on the outer peripheral surface of the tip of the second support portion 31d, which engages with the engaging protrusion 32d of the valve body holding portion 32 when the valve body holding portion 32 moves in the approaching direction as described below.

[0029] In addition, the valve body 31 has a protruding portion 31h formed by the valve body packing 31e protruding radially outward beyond the first support portion 31a, and when the valve body 31 moves in the direction away from the valve hole 1d as described below, the protruding portion 31h comes into contact with the lower end portion 34g of the box body 34, thereby restricting further movement in the direction away.

[0030] As shown in Figures 2 and 3, the valve body pressing portion 32 has a cylindrical support portion 32a and a flange portion 32b protruding radially outward from the upper end of the support portion 32a, and a female screw portion 32c that screws into the plug rod 35 is provided on the inner surface of the support portion 32a.

[0031] Furthermore, the outer peripheral surface of the flange portion 32b slides on the inner peripheral surface of the box body 34, so that the valve element holding portion 32 moves in the approaching / separating direction (up and down direction) while maintaining its posture relative to the valve hole 1d.

[0032] Furthermore, the valve disc holding portion 32 is provided with an engaging protrusion 32d on the inner peripheral surface of the lower end of the support portion 32a, and when the valve disc holding portion 32 moves in the direction approaching the valve orifice 1d, the engaging protrusion 31g of the valve disc 31 and the engaging protrusion 32d of the valve disc holding portion 32 engage with each other. The specific operations for engaging and releasing the valve disc 31 between the valve disc holding portion 32 and the valve disc will be described later.

[0033] As shown in Figures 2 and 3, the spring 33 is made of a metal coil spring, and its lower end 33a is inserted into the recess 31f of the valve body 31, while its upper end 33b is accommodated in a contracted state while abutting against the underside of the flange portion 32b of the valve body holding portion 32 via a cushioning material 37, and urges the valve body 31 and the valve body holding portion 32 in directions away from each other (directions approaching the valve hole 1d).

[0034] As shown in Figures 2 and 3, the box body 34 includes a thick-walled cylindrical portion 34a provided at the top, a thin-walled cylindrical portion 34b extending downward from the lower end of the thick-walled cylindrical portion 34a, a flange portion 34c protruding radially outward from the lower end of the thick-walled cylindrical portion 34a, a top wall portion 34d extending radially inward from the upper end of the thick-walled cylindrical portion 34a, an upper cylindrical portion 34e extending upward from the inner edge of the top wall portion 34d, and an upper flange portion 34f protruding radially outward from the upper end of the upper cylindrical portion 34e.

[0035] The box body 34 accommodates all or part of the valve body 31, the valve body holding portion 32, the spring 33 and the plug rod 35, and guides the valve body 31 and the valve body holding portion 32 along the inner surface 34h in the direction toward or away from the valve hole 1d.

[0036] In addition, the box body 34 closes the opening 1e of the main body trunk 1 by inserting the thin-walled cylindrical portion 34b into the opening 1e of the main body trunk 1 and abutting the lower surface of the flange portion 34c against the upper surface of the opening 1e of the main body trunk 1.

[0037] The plug rod 35 is a generally cylindrical member that extends vertically through the box 34 and the valve disc holder 32, and has a male thread 35a on its lower outer circumferential surface that screws into the female thread 32c of the valve disc holder 32. When the plug rod 35 rotates axially in the forward direction, the valve disc holder 32 moves (screws forward) toward the valve orifice 1d, while when the plug rod 35 rotates axially in the reverse direction, the valve disc holder 32 moves (screws back) away from the valve orifice 1d. This allows the valve disc holder 32 to move toward or away from the valve orifice 1d with a simple configuration.

[0038] The plug rod 35 has two grooves 35b formed side by side in the vertical center, and an O-ring 35e is fitted into the grooves 35b. The plug rod 35 also has a screw hole 35c formed in its upper surface.

[0039] The handle 36 comprises a main body 36a which is circular in plan view, a protrusion 36b which protrudes downward from the center of the underside of the main body 36a, a recess 36c formed in the center of the upper surface of the main body 36a, and an insertion hole 36d which penetrates the protrusion 36b in the vertical direction, and the plug rod 35 is inserted into the insertion hole 36d and fixed to the plug rod 35 by screwing it from above with a screw 35f. In addition, 36e in Figure 3 is a display plate.

[0040] The telescopic tube 4 comprises a sleeve tube 41, a first nut 42 provided at the primary side opening end of the sleeve tube 41, and a second nut 43 provided at the secondary side opening end, and is connected to the main body trunk 1 by screwing the inner surface of the first nut 42 into the outer surface of the outlet portion 1b of the main body trunk 1.

[0041] Next, the specific operation of engaging the valve disc holding portion 32 with the valve disc 31 will be described with reference to FIGS.

[0042] First, the operation of transitioning from the normal state to the valve-open state will be described.

[0043] 4(a), the valve disc holding portion 32 is disposed at the top inside the box body 34, while the valve disc 31 is biased toward the valve hole 1d by the spring 33, and the valve disc 31 opens or closes the valve hole 1d according to the pressure (water pressure) of the water flowing in from the primary inlet portion 1a. This state is the normal state in which the valve disc 31 has a backflow prevention function for the valve hole 1d.

[0044] 4(b), when the valve disc 31 closes the valve orifice 1d, if the plug rod 35 is axially rotated in the forward direction, the valve disc holding portion 32 moves (descends) toward the valve disc 31 and valve orifice 1d against the bias of the spring 33, and the engaging protrusion 32d of the valve disc holding portion 32 rides downward onto the engaging protrusion 31g of the valve disc 31 and engages with the engaging protrusion 31g (see FIG. 7). Note that in the state shown in FIG. 4(b), the valve disc holding portion 32 prevents the valve disc 31 from moving in the approaching / separating direction (up and down), and the valve is in a closed state where it is forcibly maintained closed while being biased by the spring 33.

[0045] Then, as shown in Figure 5(a), when the plug rod 35 is rotated in the opposite direction, the valve body holding portion 32 moves (rises) away from the valve orifice 1d, and as a result, the valve body 31 engaged with the valve body holding portion 32 moves (rises) away from the valve orifice 1d, opening the valve orifice 1d and transitioning to an open valve maintaining state in which the valve body 31 is forcibly maintained open.

[0046] Then, as shown in Figure 5(b), when the plug rod 35 is further rotated in the opposite direction, the valve disc holding portion 32 moves (rises) further away from the valve hole 1d, and as a result, the valve disc 31 engaged with the valve disc holding portion 32 moves (rises) further away from the valve hole 1d, and as shown in Figure 5(a), the protruding portion 31h of the valve disc 31 comes into contact with the lower end portion 34g of the box body 34 (which functions as a regulating portion), and the second support portion 31d of the valve disc 31 comes into contact with the lower end portion 35d of the plug rod 35 (which also functions as a regulating portion), thereby regulating the movement (rise) of the valve disc 31 in the direction away from the valve hole 1d.

[0047] Next, the operation of transitioning from the valve-open state to the normal state will be described.

[0048] When the plug rod 35 is further axially rotated in the opposite direction in the open valve maintaining state of Figure 5(b), as shown in Figure 6(a), the valve body holding portion 32 moves further away from the valve orifice 1d (rising), while the valve body 31 is restricted from moving away from the valve orifice 1d (rising), so the valve body holding portion 32 rises relative to the valve body 31, and as a result, the engaging protrusion 32d of the valve body holding portion 32 rides upward on the engaging protrusion 31g of the valve body 31 and releases the engagement with the engaging protrusion 31g.

[0049] Then, as shown in Figure 6(b), when the valve body 31 is released from engagement with the valve body holding portion 32, it moves (descends) toward the valve orifice 1d due to the force of the spring 33, closing the valve, and the valve body 31 returns to its normal state in which it has a backflow prevention function for the valve orifice 1d.

[0050] Thus, when transitioning from the normal state to the valve-open maintaining state, the valve disc holding portion 32 moves toward the valve orifice 1d and engages with the valve disc 31, and then the engaged valve disc holding portion 32 and the valve disc 31 move away from the valve orifice 1d, causing the valve disc 31 to forcibly maintain the valve open against the bias of the spring 33, thereby enabling transition from the normal state to the valve-open maintaining state by the simple operation of engaging the valve disc 31 with the valve disc holding portion 32. Furthermore, when transitioning from the valve-open maintaining state to the normal state, the engagement between the valve disc holding portion 32 and the valve disc 31 is released, causing the valve disc 31 to close while being biased by the spring 33, thereby enabling transition from the valve-open maintaining state to the normal state by the simple operation of disengaging the valve disc 31 with the valve disc holding portion 32. Therefore, the backflow prevention function of the check valve can be disabled and restored without disassembling or assembling the check valve. This not only significantly reduces the time and effort required for water flow tests, but also prevents dust, dirt, and the like from getting into the device and prevents parts from being lost.

[0051] In this embodiment, the valve element 31 moves in the vertical direction, but it may move in other directions as long as it opens and closes the valve hole 1d.

[0052] Furthermore, although the valve element holding portion 32 is adapted to move toward or away from the valve hole 1d by being threadedly engaged with the plug rod 35, it may be moved by other means.

[0053] Furthermore, the valve body 31 and the valve body holding portion 32 are engaged with each other by the engaging protrusion 31g and the engaging protrusion 32d, but this is not limited thereto, and they may be engaged with each other by, for example, an engaging protrusion and an engaging recess.

[0054] Furthermore, the valve body 31 and the valve body holding portion 32 are configured so that the outer surface of the valve body 31 engages with the inner surface of the valve body holding portion 32, but this is not limited to this, and for example, the inner surface of the valve body 31 may engage with the outer surface of the valve body holding portion 32.

[0055] Furthermore, the engagement between the valve body 31 and the valve body holding portion 32 is not limited to an engagement with an engagement convex portion or an engagement concave portion, and may be by other configurations such as an O-ring, a magnet, or a ring.

[0056] Furthermore, the lower end portion 35d of the plug rod 35 and the lower end portion 34g of the box body 34 are used as restricting portions for restricting the movement of the valve body 31 in the direction away from the valve orifice 1d, but it is also possible to use only one of these restricting portions, or to use a restricting portion of a different structure.

[0057] Furthermore, the movement of the valve body 31 in the direction away from the valve hole 1d is restricted, and the engagement between the valve body holding portion 34 and the valve body 31 is released when only the valve body holding portion 34 moves in the direction away from the valve hole 1d, but the engagement between the valve body holding portion 34 and the valve body 31 may be released by other configurations.

[0058] Furthermore, although the check valve 3 has been described as being applied to a stop valve, it may also be applied to other water facilities.

[0059] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the same scope as the present invention or within an equivalent scope. [Explanation of symbols]

[0060] 1...Main body 1a...Inlet part 1b... Outlet part 1c...Bulkhead 1d...valve orifice 1e…Opening 1f...Valve chamber 2...Water stop valve 2a...Ball valve body 2b…Secondary stopper rod 2c...Sub-stopper rod holder 2d...Cap 2e... Lever handle 3...Check valve 31...Valve body 31a...first support part 31b…bottom 31d…Second support part 31e...Valve body packing 31f...recess 31g...Engagement convex part 31h...Protruding part 32...Valve body retainer 32a...Support part 32b…Tsubabe 32c...female thread 32d…Engagement convex portion 33...Spring (biasing member) 33a...lower end 33b...Top end 34...Box body 34a...Thick-walled cylinder part 34b...Thin wall cylinder part 34c...Flange part 34d…Ceiling wall part 34e...Upper cylinder part 34f...Upper flange 34g…Lower end (regulating part) 34h…Inner peripheral surface 35...stopper rod 35a…Male thread part 35b…Groove 35c...Screw holes 35d...Lower end (regulating part) 35e...O-ring 35f...Screw 36...Handle 36a...Main body 36b…Protrusion 36c...recess 36d...insertion hole 36e…Display board 37...Cushioning material 4...Extensible tube 41...Sleeve 42...First nut 43...Second nut

Claims

1. A check valve for waterworks equipment that allows water to flow from the primary side to the secondary side by opening the valve hole of the waterworks equipment, and prevents water from flowing back from the secondary side to the primary side by closing the valve hole, a valve body that opens or closes the valve hole; a valve body pressing portion provided on the opposite side of the valve hole with respect to the valve body; a biasing member that biases the valve body toward the valve hole, a normal state in which the valve element is biased by the biasing member and opens or closes in response to water pressure from the primary side to the secondary side; The valve body has at least an open valve maintaining state in which the valve body forcibly maintains the valve open while resisting the biasing force of the biasing member, When transitioning from the normal state to the valve-open state, the valve disc holder moves in a direction approaching the valve hole and engages with the valve disc, and then the engaged valve disc holder and the valve disc move in a direction away from the valve hole, forcibly maintaining the valve open while the valve disc resists the biasing force of the biasing member. A check valve for water supply equipment characterized in that, when transitioning from an open valve maintaining state to a normal state, the engagement between the valve body and the valve body pressing portion is released, causing the valve body to close while being biased by the biasing member.

2. The valve body is provided with an engaging protrusion or an engaging recess that can be engaged with the valve body pressing portion, The valve body holding portion is provided with an engaging protrusion or an engaging recess that can engage with the valve body, 2. A check valve for water supply equipment as described in claim 1, wherein when the valve body holder moves in a direction approaching the valve hole, the engaging protrusions of the valve body and the valve body holder or the engaging protrusions and engaging recesses of the valve body and the valve body holder engage with each other.

3. A check valve for water supply equipment as described in claim 2, wherein the valve body has a support portion extending toward the valve body holding portion, and the support portion is provided with an engaging protrusion or engaging recess that engages with the valve body holding portion.

4. 3. A check valve for water supply equipment as described in claim 2, wherein the valve body pressing portion has a support portion extending toward the valve body, and the engaging protrusion or engaging recess that engages with the valve body is provided on the support portion.

5. a restricting portion that restricts movement of the valve body in a direction away from the valve hole, A check valve for water supply equipment as described in claim 1, wherein when transitioning from an open valve maintaining state to a normal state, the regulating portion regulates the movement of the valve body in the direction away from the valve hole, and only the valve body holding portion moves in the direction away from the valve hole, thereby releasing the engagement between the valve body and the valve body holding portion.

6. a plug rod connected to the valve body pressing portion in a threaded state is provided; 2. A check valve for plumbing equipment as described in claim 1, wherein the valve body retainer moves toward the valve hole when the plug rod rotates axially in a forward direction, and the valve body retainer moves away from the valve hole when the plug rod rotates axially in a reverse direction.

7. A stop valve comprising the check valve for water supply equipment according to any one of claims 1 to 6.

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