KR200360195Y1 - A swing check valve and backflow-preventer adopting the same - Google Patents

Abstract

The present invention relates to a swing check valve and a backflow preventer employing the same. According to the present invention a hollow body formed with a hollow forming a flow path; A first pivotal arm rotatably coupled to a bracket formed inside the body; A second pivoting arm whose one end is pivotally coupled to the first pivotal arm; A disk coupled to the other end of the second pivotal arm to selectively open and close the flow path of the body by a pivoting motion; Rotation guide means for guiding the rotational movement of the disk; And elastic bias means for providing an elastic force to close the flow path with respect to the disk, wherein the maximum pivot radius of the disk is achieved by combining the pivot radius of each of the first pivot arm and the second pivot arm. A swing check valve is disclosed. In addition, a hollow is formed between the inlet and the outlet to form a flow path, a portion of the cylindrical case is cut open the opening; First and second swing check valves according to claim 1 or 2, which are spaced apart at predetermined intervals on the inlet and outlet sides of the cylindrical case; A spacer for maintaining a distance between the first and second swing check valves; And a cover sleeve surrounding the outer surface of the cylindrical case to seal the opening, wherein outer diameters of the first and second swing check valves are smaller than inner diameters of the cylindrical case, and thus, the inside of the cylindrical case through the opening. It is inserted into and fixed to the backflow preventer, characterized in that each of the components are mutually disassembleable assembly.

Description

A swing check valve and backflow-preventer adopting the same}

The present invention relates to a swing check valve and a backflow prevention device using the same, and more particularly, a swing check valve installed in a pipeline such as a water supply system to prevent backflow, and employing the same to prevent the mixing of fluid due to a back pressure and a reverse punch. It relates to a backflow preventer.

In the conventional water supply system, a water supply system adopts a method of installing a water tank to supply water in a building, because the purpose was to mandate the installation of emergency water supply facilities, to mitigate pressure fluctuations in the drain pipe, and to stabilize water supply in the dry season. However, this method caused water pollution and wasted energy, so the direct water supply method and the direct direct pressure method appeared as alternatives. The direct water supply system refers to a method of directly supplying water by connecting a water supply pipe in the main water main, and the direct direct pressure method refers to a method of supplying water directly from a water supply drain pipe without passing through a water reservoir in a building. In order to supply water safely in the direct pressure and direct feed water supply system, it is important to prevent backflow of the fluid.

As a general means of preventing backflow of fluid, a swing check valve is used in which the fluid flows in only one direction and the valve closes automatically in the reverse flow. 1 illustrates a swing check valve, which is an example of such a conventional swing check valve.

Referring to Figure 1, the conventional swing check valve 10 is fixed to the rotating arm 13 and the free end of the rotating arm 13 is rotated around the rotating shaft 11 in the cylindrical case to the fluid path And a disk 15 for opening and closing. The disk 15 is provided with a disk sheet 17.

In the operation of the swing check valve 10 as described above, when the fluid flows in the direction of the arrow through the inlet 12 in a constant pressure state, the disk 15 is rotated upward due to the hydraulic pressure. On the other hand, when the pressure at the inlet 12 is lower than the pressure at the outlet, the pressure of the inlet 12 is lowered, and the disk 15 rotates downward to close the flow path, thereby preventing backflow of the fluid.

However, the conventional swing check valve has various limitations in blocking the flow path because the disk 15 is rotated around one rotating shaft 11 supporting one rotating arm 13. For example, even if the disk 15 rotates upward in the static pressure to block the flow path, part of the disk structure is still placed in the flow path, thereby preventing the flow of fluid and acting as a resistance. To prevent this, the angle of rotation of the pivoting arm 13 may be increased so that the disk may be completely out of the flow path at the time of rotation. However, in this case, the size of the valve is inevitably large due to the securing of space necessary for the rotational arm and the rotation of the disk. In addition, there is a problem that the response of opening and closing the valve due to the change in the hydraulic pressure of the fluid is reduced, the disk does not block the flow path quickly when the switch to the reverse pressure.

In addition, the disk 15 is fixed only to the free end of the rotating arm 13, the contact sealing state of the disk seat 17 and the cylindrical case is not precise, or due to repeated use for a long time due to the rotating shaft ( When 11) is loosened, the sealing state is further worsened, causing a backflow leak in a state in which the disk 15 blocks the flow path, thereby causing a problem that the pollutant on the outlet side flows into the inlet side.

On the other hand, it is common to use a backflow preventer employing two or more swing check valves to prevent backflow by backflow and back siphonage to prevent water contamination inside the pipeline. Here, the reverse flow due to the back pressure is a phenomenon that occurs when the pressure of the other system is increased when the water supply pipe is directly connected to the piping system of the other system. The reverse flow due to the inverse-equilibrium action causes reverse flow when the pressure in the pipe becomes negative, for example, when the supply side is cut off, when the pump is stopped due to a power failure, and the supply-side piping is broken to supply water. Occurs when interrupted.

In general, the check valve 10 has no difficulty in blocking the back flow of the fluid inside the pipe in the normal use state or normal stop state of the water flowing through the pipe, but in order to prevent the back flow caused by the back pressure, the backfill operation, etc. There was a limit. In order to solve this problem, a double check valve was developed, but the valve was not completely closed due to foreign matter stuck to the valve plate or damage to the valve itself.

In order to solve the above problems, the diaphragm type backflow preventer 20 shown in FIG. 2 has been proposed. The diaphragm type backflow preventer 20 is provided with a lift type first check valve 23 and a second check valve 25 that operate independently up and down the flow passage 22 installed in the case 21, and therebetween. A pressure adjusting mechanism is provided. The pressure adjusting mechanism includes a bypass flow path 28, a diaphragm 24, and a bypass valve 26, and the diaphragm 24 and the bypass valve 26 are located in the intermediate chamber 29. However, the non-return checker 20 as described above has a problem that the size is large and the weight is inconvenient, and the pressure loss is extremely large because it is equipped with a separate mechanically independent pressure adjusting mechanism as a means for reducing the pressure. In addition, the backflow preventer 20 has a problem that the flow of the fluid is hindered by the lift check valve, and the components constituting the integrated check valve are difficult to maintain.

The present invention was devised to solve the above problems, and includes a plurality of rotating mechanisms and rotating guide means, so that the disk does not interfere with the flow path when the flow path is opened, and the swing check can block the flow path with a high precision sealing state. It is an object to provide a valve.

Another object of the present invention is to adopt the swing check valve as described above in a double manner to effectively block the flow path in the event of a back pressure or a reverse punch without the use of the existing complicated pressure adjusting mechanism, and to maintain each component as a prefabricated structure. It is to provide a backflow preventer which is very convenient to repair.

1 is a cross-sectional view showing a conventional swing check valve.

2 is a cross-sectional view showing a conventional diaphragm type backflow preventer.

Figure 3a is a cross-sectional view showing a closed state of the swing check valve according to an embodiment of the present invention.

Figure 3b is a cross-sectional view showing an open state of the swing check valve according to an embodiment of the present invention.

Figure 4 is a perspective view showing a backflow preventer according to a preferred embodiment of the present invention.

Figure 5 is an exploded perspective view schematically showing the configuration of the backflow preventer according to a preferred embodiment of the present invention.

6 is a cross-sectional view taken along the line VI-VI of FIG. 4.

7 is a cross-sectional view showing that the backflow preventer according to an embodiment of the present invention operates in an open state.

8 is a cross-sectional view showing a state in which the reverse operation in the backflow preventer according to an embodiment of the present invention.

9 is a cross-sectional view showing a state in which the operation in the reverse ephon operation in the backflow preventer according to a preferred embodiment of the present invention.

10 and 11 are perspective views illustrating a process of assembling a backflow preventer according to a preferred embodiment of the present invention.

<Description of main reference numerals in the drawings>

30 ... swing check valve 31 ... body

32 ... valve disc 33 ... disc seat

34 ... Bracket 34a ... First pivot

35 ... 1st pivot arm 35a ... 2nd pivot

36.2nd pivot arm 37 ... fastening member

38.Rotating guide bar 39 ... Bias means

110. Cylindrical case 120. Cover sleeve

130 ... Spacer 140 ... Cock Valve

170 ... relief valve

In order to achieve the above object, the swing check valve according to the present invention is a cylindrical body formed with a hollow to form a flow path; A first pivotal arm rotatably coupled to a bracket formed inside the body; A second pivoting arm whose one end is pivotally coupled to the first pivotal arm; A disk coupled to the other end of the second pivotal arm to selectively open and close the flow path of the body by a pivoting motion; Rotation guide means for guiding the rotational movement of the disk; And elastic bias means for providing an elastic force to close the flow path with respect to the disk, wherein the maximum pivot radius of the disk is achieved by combining the pivot radius of each of the first pivot arm and the second pivot arm. do.

Preferably, the rotation guide means is one end is coupled to the body, the other end is a rotation guide bar coupled to the hinge rotatably to one side of the disk.

According to another aspect of the present invention, a hollow case is formed between the inlet and the outlet to form a flow path, a portion of the cylindrical case is cut open the opening formed; First and second swing check valves according to claim 1 or 2, which are spaced apart at predetermined intervals on the inlet and outlet sides of the cylindrical case; A spacer for maintaining a distance between the first and second swing check valves; And a cover sleeve surrounding the outer surface of the cylindrical case to seal the opening, wherein outer diameters of the first and second swing check valves are smaller than inner diameters of the cylindrical case, and thus, the inside of the cylindrical case through the opening. It is inserted into and fixed to, each of the components is provided with a backflow preventer, characterized in that the mutual disassembly assembly.

Preferably, each of the first and second swing check valves. It is formed to protrude so as to be the same as the radius of curvature of the cylindrical case, it is assumed that the stopper projection is formed in the cylindrical case to prevent excessive insertion.

More preferably, the backflow prevention device comprises: a first space communicating with a chamber formed between the first and second swing check valves; A second space connected to the inlet and a connection pipe and having a discharge hole for discharging the fluid to the outside; And a disk installed between the first space and the second space to selectively open and close the flow path according to mutual pressure, wherein the disk is slid when the pressure of the first space is greater than the pressure of the second space. It is further to include a relief valve for opening the flow path between the first space and the second space and at the same time discharge the fluid flowing through the valve hole to the outside.

Hereinafter, the present invention will be described in detail with reference to Examples, and in order to help understanding of the present invention, it will be described in detail with reference to the accompanying drawings. However, embodiments according to the present invention can be modified in many different forms, the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art.

3A and 3B show a swing check valve 30 according to a preferred embodiment of the present invention, in which FIG. 3A shows a flow path closed state and FIG. 3B shows a flow path open state, respectively.

Referring to the drawings, the swing check valve 30 according to a preferred embodiment of the present invention is mounted in the body 31, the body 31 constituting the flow path to selectively block the flow of fluid in accordance with the hydraulic pressure And a disk 32.

The body 31 is mounted in a pipeline (not shown) to which the fluid is supplied, for example, by fitting or the like, and is preferably cylindrical in shape so that the fluid can flow therein.

The disk 32 opens and closes the flow path by selectively sealingly contacting the inner circumferential portion 31a of the body 31 by the rotational motion. The disk 32 is attached to the disk sheet 33, for example, made of a flexible material such as rubber for packing. More preferably, the disk sheet 33 is also attached to the inner circumferential portion 31a of the body 31. A packing member (not shown) for contacting and sealing may be further provided.

A bracket 34 coupled to or extending from the body 31 is provided inside the body 31.

The swing check valve 30 according to the present invention includes a plurality of pivoting arms for rotating the disk 32. Specifically, the swing check valve 30 is coupled to the first pivotal shaft 34a of the bracket 34 to pivot. It is the rotational arm 35 and the 2nd rotational arm 36 which the one end couples to the 2nd rotational axis 35a of the said 1st rotational arm 35, and rotates.

The disk 32 is rotatably fixed to the other end of the second pivotal arm 36 to selectively open and close the flow path of the body 31 in accordance with the rotation of the second pivotal arm 36.

According to the present invention, the rotation guide means for guiding the rotation by limiting the movement path of the disk 32 is provided.

According to a preferred embodiment of the present invention, the rotation guide means includes a rotation guide bar 38, one end of which is coupled to the body 31 by a fastening member 37. The other end of the rotation guide bar 38 is hingedly coupled to the disk 32. Preferably, the rotation guide bar 38 is hinged to the coupling pin 32a extending from one side of the disk 32, in which the disk 32 is coupled to the body 31 to block the flow path. In one state, the disk sheet 33 and the packing member (not shown) of the body 31 are firmly engaged with each other so that the sealing state can be maintained.

In the swing check valve of the present invention, when the hydraulic pressure at the inlet port 300 side is equal to or lower than the hydraulic pressure at the outlet port 400 side, the disk 32 rotates to close the flow path of the body 31. An elastic bias means is provided.

Preferably, the elastic bias means has one end supported by the body 31 or the bracket 34, the other end thereof is coupled to the engaging projection 34b formed on the first pivotal arm 35, the disk 32 It may be a torsion spring (39) for biasing the body 31 in the direction. As described later, the elastic force of the elastic biasing means is appropriately set in consideration of the hydraulic pressure difference between the inlet 300 and the outlet 400.

Then, the operation of the swing check valve according to the preferred embodiment of the present invention having the configuration as described above will be described.

The swing check valve of the present invention can be fastened by inserting or fitting into a pipeline through which fluid is supplied.

In the state where the fluid does not flow because the pressure at the inlet port 300 side is lower than or equal to the pressure at the outlet port 400 side, as shown in FIG. 3A, the disk 32 contacts the inner circumferential portion 31a of the body 31. To block the flow path. At this time, the disk 32 is pressed by the biasing means 39.

In this state, when the hydraulic pressure of the inlet port 300 side is higher than the hydraulic pressure of the outlet port 400 side, the fluid is introduced while pushing the disk (32). Arrows in the drawing indicate the direction of the fluid. If the pressure difference between the pressure at the inlet port 300 side and the outlet 400 side is greater than the elastic force for the elastic bias means 39 to press the disk 32, the disk 32 as shown in FIG. The flow path is opened while rotating.

At this time, the first pivotal arm 35 rotates clockwise around the first pivotal shaft 34a, and at the same time, the second pivotal arm 36 pivots about the second pivotal shaft 35a. do. In addition, the disk 32 coupled to the free end of the second pivotal arm 36 is also rotated in a clockwise direction, for example, since one side of the disk 32 is coupled to the pivoting guide bar 38. The movement is guided reliably.

According to the operation of the swing check valve according to the present invention, the disk 32 is rotated by a rotation radius in which the radius of rotation of the first rotational arm 35 and the radius of rotation of the second rotational arm 36 are combined with each other. . That is, since the second pivotal arm 36 rotates, for example, at the radius of curvature R2, while the first pivotal arm 35 is rotated at, for example, the radius of curvature R1, the disk 32 The turning radius of can be up to R1 + R2. Therefore, the opening area is further increased as compared with the rotation by the conventional single pivot arm, so that the flow path can be completely opened without interference by the disk. At the same time, since the rotational movement of the disk is performed by the complex linkage of the first and second pivotal arms 35 and 36, the diameter or size of the valve body 31 needs to be increased to obtain this maximum rotational radius. none. Therefore, it is possible to prevent the structure of the body 31 from being enlarged while minimizing pressure loss by not disturbing the flow of the fluid when the disc 32 is opened.

On the other hand, if the pressure difference between the inlet port 300 side and the outlet port 400 side is smaller than the elastic force applied to the disk 32 by the elastic bias means 39, the disk 32 is rotated back to its original position. The flow path is blocked as shown in 3a. At this time. Since the rotation of the disk 32 is guided stably by the rotation guide bar 38, the disk seat 33 is in close contact with the packing member provided in the body inner peripheral portion 31a without shaking or deviating from the rotation path. Good sealing can be achieved.

According to another aspect of the present invention, there is provided a backflow preventer employing the swing check valve. 4 to 6 shows a backflow preventer according to a preferred embodiment of the present invention. However, detailed parts of each swing check valve are omitted in FIG. 5.

Referring to the drawings, the backflow preventer according to the present invention is the cylindrical case 110, the first swing check valve 30 and the second swing check valve 30 'and the cover sleeve mounted in the cylindrical case 110 120.

The cylindrical case 110 is a cylindrical tube having a hollow formed to form a flow path, and an opening 111 having a portion thereof cut into a predetermined size is formed.

The structures of the first and second swing check valves 30 and 30 'are the same as in the above-described embodiment. The swing check valves 30 and 30 ′ are mounted to be spaced apart from each other in the cylindrical case 110 through the opening 111 of the cylindrical case 110. That is, as shown in FIG. 10, the outer diameters of the bodies 31 of the first and second swing check valves 30 and 30 ′ are smaller than the inner diameter of the cylindrical case 110, so that the swing check valve 30 is provided. 30 'may be inserted through the opening 111 formed in the cylindrical case 110, and then may be fitted to the inner circumference of the cylindrical case 110, respectively. In this case, stopper protrusions 40 and 40 'each having a radius of curvature equal to the radius of curvature of the outer circumferential surface of the cylindrical case 110 are formed on a portion of the outer circumferential surface of the first and second swing valve valves 30 and 30'. Thus, when the swing check valves 30 and 30 'are coupled to the cylindrical case 110, excessive insertion can be prevented. Preferably, a sealing member such as O-rings 51a and 51b may be further provided between the swing check valves 30 and 30 'and the cylindrical case 110.

The first and second swing check valves 30 and 30 ′ may be maintained by a spacer 130. The spacer 130 is a part of the cylindrical body having the same radius of curvature as the cylindrical case 110, and the protrusions 130a and 130b formed on the body at the time of joining are formed in the stopper protrusions 40 and 40 '. By being inserted into the grooves 40a and 40a ', the first and second swing check valves 30 and 30' can be fixed in place while maintaining mutual separation.

As illustrated in FIG. 11, the cover sleeve 120 is fitted to the outer surface of the cylindrical case 110 to surround the spacer 130 and has a shape corresponding to the shape of the cylindrical case 110. Has Preferably, a sealing member such as O-rings 52a and 52b is provided between the cover sleeve 120 and the cylindrical case 110 to completely seal the opening 111. It is preferable that the cover sleeve 120 is provided with an assembly hole 131 and a cock valve 140 for controlling the flow of the fluid.

The backflow preventer of the present invention is very advantageous for installation and maintenance because each component is configured to be disassembled and assembled.

In the present invention, it is to be understood that the combination of the swing check valve, the cylindrical case, and the cover sleeve can be combined by various methods such as a screw coupling method and a nut coupling method as well as the illustrated embodiment.

Preferably, a relief valve may be employed in the backflow preventer of the present invention. The relief valve is mounted to communicate with a chamber Si between the first and second swing check valves 30 and 30 ', as shown in FIG.

The relief valve 170 includes a body 171 whose internal space is divided into a first space S1 and a second space S2. The relief valve 170 is coupled so that the first space S1 is connected to the chamber Si of the backflow preventer.

A support 172 is formed in the body 171 of the relief valve 170, and the support 172 is installed to be slidable in the longitudinal direction.

A disk 174 is installed at the end of the plunger 173 to open and close the first space S1 and the second space S2 according to the reciprocating motion of the plunger 173. Preferably, the disk sheet 175 of a flexible material is attached to the upper surface of the disk 174 to make a sealing contact.

The body 171 having the second space S2 has a discharge hole 171a penetrated to the outside from the second space S2. The discharge hole 171a serves to discharge the fluid or air at the time of a back pressure or a reverse-fund operation in the backflow preventer as described below. In addition, a spring 176 is interposed between the support 172 and the disk 174 to bias the disk 174 to be closed.

The second space S2 is in communication with the space on the side of the inlet 300 through the connecting pipe 180. Therefore, the pressure in the second space S2 may be maintained to be equal to the hydraulic pressure of the inlet 300.

Then, the preferred operation of the backflow preventer according to the present invention having the configuration as described above will be described in detail. For convenience of description, the hydraulic pressure at the inlet 300 side is P1, the hydraulic outlet at the side 400 is P3, and the hydraulic pressure in the chamber S1 between the first and second swing check valves 30, 30 '. Is called P2.

6 shows that when the inlet pressure P1 is not large enough, i.e., the difference between the inlet pressure P1 and the outlet pressure P3 is not greater than the elastic pressing force of the first and second swing check valves 30, 30 '. The case is shown.

In this state, as described above, the first and second swing check valves 30 and 30 'block the flow of the fluid. At this time, the pressure of the second space S2 of the relief valve 170 becomes P1, and the second space S2 is closed by the disk 174.

7 shows the case where the inlet pressure is sufficiently large, that is, the difference between the inlet pressure P1 and the outlet pressure P3 is greater than the elastic pressing force of the first and second swing check valves 30 and 30 '. That is, the relationship of P1> P2> P3> is maintained.

In this case, the first swing check valve 30 is opened by the pressure P1. In the drawing, the arrow indicates the direction of the fluid. In this direction, the fluid passing through the first swing check valve 30 is decompressed to the pressure P2 by the resistance of the first swing check valve 30 and thus the chamber ( Si) is reached. Subsequently, the second swing check valve 30 ′ is opened by the pressure P2, and the fluid passing through the second swing check valve 30 ′ is reduced in pressure P3 and flows toward the outlet 400. Thus, the fluid normally flows from the inlet 300 to the outlet 400 side.

At this time, since the pressure P1 of the second space S2 of the relief valve 170 is greater than the pressure P2 of the first space, the disk 174 of the relief valve is kept closed.

If the inflow pressure P1 is lowered to prevent fluid flow, the flow path is blocked while the first and second swing check valves 30 and 30 'are closed as shown in FIG. 6.

On the other hand, the relief valve 170 may further exhibit its function when the swing check valves 30 and 30 'are not smoothly operated.

If the outflow pressure P3 is greater than the internal pressure P2 of the chamber or the inflow pressure P1 is lower than the atmospheric pressure, for example, and the hysteresis occurs, the first and second swing check valves 30 are normal. 30 'is closed so that the flow path is closed so that the pollutant on the outlet 400 side cannot flow to the inlet 300 side.

However, as shown in FIG. 8, although the first swing check valve 30 is closed, the second check valve 30 ′ may be damaged by the foreign matter 117 or the discs 32 and 32 ′ due to a failure. A gap may occur between the valve bodies 31 and 31 ′, causing a source of contamination from the outlet 400 side. If such a state is left or the pressure P3 on the outlet 400 side is excessively high, damage is caused to the first swing check valve 30, so that the pollutant is introduced into the inlet port 300. The result can be. Therefore, in this case, the relief valve 170 serves as a means for relieving the outflow pressure (P3) to discharge the pollutant to the outside.

In this state, since the pressure P2 of the first space S1 of the relief valve 170 is P1 <P2 greater than the pressure P1 of the second space S2, The fluid presses the disk 174 and thus the plunger 173 and the disk 174 slide downward, thereby opening the flow path between the first space S1 and the second space S2.

At this time, the disc when the pressure difference (P1-P2 = ΔP) is less than the appropriate value, for example, ΔP = 14kPa (0.14kgf / cm ² ), which is the recommended value in the specification of the pressure-sensitive backflow preventer for water supply from the Korea Water and Sewerage Association (KWWA). Spring 176, disk 174 and body bore etc. may be designed such that 174 is lowered to open the flow path.

Subsequently, the inlet of the connecting pipe 180 is closed by the sliding disk 174 and the discharge hole 171a formed in the second space S2 is opened. Therefore, the fluid and the pollutant in the first space S1 may be discharged to the outside through the discharge hole 171a of the second space S2. Therefore, it is possible to solve the back pressure and discharge the pollutant source to the outside without causing any damage to the first swing check valve 30.

In another case, even when a gap is generated between the first swing check valve 30 and the body 31 and leaks, the pollutant is externally released while dropping hydraulic pressure through the discharge hole 171a according to the same process. Can be discharged.

Subsequently, when the inflow pressure P1 increases again to a normal state, the disk 174 of the relief valve 170 rises again to close the first space S1 and at the same time, the first and second swing check valves. The flow path is normally flowed as the 30 and 30 'are opened.

On the other hand, as described above, the first swing check valve 30 is closed because P1 is lowered in the inverse-fund operation state in which the pressure at the inlet 300 is lowered to atmospheric pressure. At this time, the first swing check valve 30 is shown in FIG. That is, the reverse pressure acts on the chamber Si so that ΔP may be, for example, 0.14 kgf / cm ² or less, or the pressure P2 may be higher than the pressure P1. At this time, the spring 176 of the relief valve 170 pressurizes the disk 174, and the relief valve 170 is opened so that the fluid inside the chamber Si is discharged through the discharge hole 171a. Thus, the fluid present in the chamber does not flow back to the water supply and prevents the contaminated fluid from entering the water supply.

Although an embodiment of the present invention has been described as a non-return valve employing a relief valve, the non-return valve of the present invention can be used alone without employing the relief valve.

Optimal embodiments of the present invention described above have been disclosed. Although specific terms have been used herein, they are used only for the purpose of describing the present invention in detail to those skilled in the art and are not used to limit the scope of the present invention as defined in the claims or the claims.

According to the swing check valve and the backflow preventer according to the present invention, sufficient rotation of the disk can be achieved without increasing the cylindrical body, thereby minimizing the resistance generated by the disk interfering with the fluid. At the same time, a means for guiding the rotation of the disk is employed, whereby the opening and closing movement of the disk is made stable.

In addition, the backflow preventer of the present invention is configured to be assembled and disassembled each component has the advantage that the installation and maintenance is convenient.

In addition, the relief valve can effectively block backflow of fluid and influx of contaminants in the event of a back pressure or a back-filling phenomenon without using a complicated pressure regulating mechanism.

Claims (3)

A cylindrical body having a hollow forming a flow path; A first pivotal arm rotatably coupled to a bracket formed inside the body; A second pivoting arm whose one end is pivotally coupled to the first pivotal arm; A disk coupled to the other end of the second pivotal arm to selectively open and close the flow path of the body by a pivoting motion; Rotation guide means for guiding the rotational movement of the disk; And And elastic bias means for providing an elastic force to close the flow path with respect to the disk. The maximum turning radius of the disk is a swing check valve, characterized in that made by combining the turning radius of each of the first and second rotating arm. The method of claim 1, The rotation guide means, One end is coupled to the body, the other end is a swing check valve, characterized in that the rotation guide bar is hinged rotatably coupled to one side of the disk. A backflow preventer comprising at least one swing check valve according to claim 1.