JPH07293721A - Bypass valve for check valve - Google Patents

Abstract

PURPOSE:To provide a bypass valve which is actuated in an interlocking manner with the actuation of a check valve, opened when the water pressure in the down stream abnormally rises, and prevents the water hammer when the non-return valve is actuated. CONSTITUTION:A bypass passage 12 to be communicated with a downstream port 13 and an upstream port 15 is provided in a valve box 11 of a check valve 1, and a bypass valve 2 to open/close a valve seat 14 of the valve box of the flow passage is mounted. This valve is provided with a valve element to be attached/detached to/from the valve seat of the valve box, and the valve element is energized in the direction to constantly close the valve by an elastic spring 29 from the rear side. When the water pressure in the downstream is abnormally increased, the check valve is closed to prevent the reverse flow to the upstream, and the water pressure presses back the valve element against the energizing force of the elastic spring of the bypass valve to be detached from the valve seat of the valve box, and the downstream is communicated with the upstream in the check valve. The water pressure in the downstream is rapidly released to prevent the occurrence of the water hammer. When the abnormality in the flow passage is converged, the bypass valve is automatically returned to the original condition together with the cheeck valve. The water hammer when the flow passage is in an abnormal condition is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bypass valve attached to a check valve installed in a pipeline.

[0002]

2. Description of the Related Art When a pump that maintains the water pressure in a flow path fails and stops, or when the use of water on the downstream side is temporarily interrupted, the water pressure on the downstream side exceeds that on the upstream side. May flow back to the upstream side. In order to prevent this phenomenon in advance, a check valve is installed in a key part of the flow path, and when the water pressure on the downstream side rises abnormally, the valve body is closed to shut off the flow path and prevent back flow from the downstream side. It is set to block.

When the check valve operates, the backflow from the downstream side can be prevented as intended, but the downstream side is closed due to this, and there is a risk that the water pressure will temporarily rise rapidly and a pressure wave will be generated. Inevitable. This wave sometimes grows extremely strongly, and it is not uncommon for it to give an unbearable impact to members such as a pipe material, a valve box, and a valve body that form a flow path, leading to destruction.
This phenomenon is widely known as water hammer or water hammer, and taking effective measures is one of the important issues in this technical field. In other words, in the flow path equipped with the check valve, it is indispensable to take action to prevent the pressure on the downstream side from rapidly increasing as the check valve operates.

FIG. 6 shows an example of a conventional technique which realizes this measure. In the figure, a bypass valve provided with a bypass passage 112 that communicates with a downstream side and an upstream side inside a valve box 111 of a check valve 101, and a valve body 122 that opens and closes a valve box valve seat 114 of this bypass channel. 102 is attached.
In this figure, the check valve 101 itself is pushed by the water pressure from the upstream side (from the bottom to the top of the drawing sheet) to rotate in a folded state around the valve shaft 116 to open the flow path. There is 2
It is composed of a sheet of valve body 117 and an elastic spring 118 that urges the valve body in the closing direction. Normally, in this state, the water force exceeds the urging force of the elastic spring to open the flow path to allow water to flow. .
When an abnormal situation occurs and the water pressure on the downstream side rises abnormally or the water pressure on the upstream side falls abnormally, the urging force of the elastic spring overcomes the pressure on the upstream side and pushes back the valve element 117, so that the valve element The valve shaft is rotated about its axis to be displaced to a horizontal position to close the flow path. As a result of this operation, backflow from the downstream side is blocked and the purpose is achieved.

The bypass valve 102 connects the downstream side and the upstream side so as to prevent an abnormal increase in water pressure on the downstream side, and relaxes the pressure on the downstream side in order to prevent a water hammer after the check valve is activated. . That is, when the check valve 101 is actuated and the observer manually rotates the handle 128 attached to the outer end of the valve rod 127 at the same time, the valve body 122 of the bypass valve 102 retracts and the bypass flow passage 112 of the check valve 101. And the downstream side and the upstream side communicate with each other, and the high water pressure on the downstream side decreases. After observing the state, when the check valve is opened and the abnormality of the flow path is converged, the observer may rotate the handle 128 again to close the bypass valve 102 and restore the original steady state. Such a correspondence is impossible.

[0006]

If the construction schedule is incorporated in advance on the upstream side and the downstream side and the pump is to be stopped, the bypass valve attached to the check valve should be opened correspondingly. However, it is unavoidable that the number of check valves is large and that the number of check valves is large and that the distance between check valves is long. At that time, the work of checking the check valves one by one and opening and closing the bypass valve is extremely troublesome, and if there are a large number of targets, there is no concern that work mistakes such as forgetting to open and closing will be added. Absent. Furthermore, if the pump is stopped unexpectedly and unexpectedly, the check valve operates to prevent the back flow of the flow path as intended, but the bypass valve does not automatically open and close. The bypass valve, which should prevent the occurrence of the above, is likely to induce an accident without exerting any effect, and has a big problem that it cannot fully fulfill the purpose of crisis management.

In order to solve the above problems, it is an object of the present invention to provide a bypass valve that automatically suppresses an increase in water pressure on the downstream side when the check valve is actuated and the check valve is closed. To do.

[0008]

A bypass valve of a check valve according to the present invention is attached to a bypass flow passage communicating with an upstream side and a downstream side in a check valve interposed in a flow passage, The valve body that opens and closes the valve box valve seat that communicates with the bypass flow passage of is movable forward and backward, and the elastic spring that constantly urges the valve body in the closing direction is interposed so that it can expand and contract. Settled.

Specifically, the downstream side 1 of the bypass passage 12 provided in the valve housing 11 of the check valve 1 and communicating with the upstream side and the downstream side.
3 is provided with a valve box valve seat 14, and the bypass valve 2 for opening and closing the valve box valve seat 14 is a valve body 22 having a valve seat surface 21 at the tip for attaching to and detaching from the valve box valve seat, and the back surface of the valve body 22. 23, a valve body shaft 24 fixed to 23, an engagement box 25 that holds the rear end of the valve body shaft 24 so as to move forward and backward, and a valve box 26 that is fixed to the rear end of the engagement box 25 and screwed forward and backward with the valve box 26. It is preferable that the valve rod 27, the handle 28 attached to the outside of the valve box at the rear end of the valve rod 27, and the elastic spring 29 interposed between the front surface of the engagement box 25 and the back surface 23 of the valve body.

As another specific configuration, the valve body 22 of the preceding example,
Instead of the valve body shaft 24, a swing valve body 32 that is rotatably supported with a pin 31 as a fulcrum, and a push rod 33 that is crimped to the back surface of the swing valve body 32 may be used.

As a further embodiment, the valve body 2
2. Instead of the valve body shaft 24 and the engagement box 25, the tip end of the valve rod 27 penetrates the downstream opening 41 and the upstream opening 42 that communicate with the downstream opening 13 and the upstream opening 15 of the check valve, respectively. A configuration in which a tubular casing 43 is attached, and a spherical valve element 44 and an elastic spring 45 for urging the spherical valve element 44 from the rear side are inserted into the casing 43 is also preferable.

[0012]

In the bypass valve of the check valve according to the present invention, when the water pressure in the pipeline is flowing at a normal level, the valve body is biased from the rear by the elastic spring and the valve seat surface thereof is a check valve. Since it is crimped to the valve box valve seat surface of the bypass passage, the passage is closed and the communication between the downstream side and the upstream side in the check valve is cut off. If an abnormality occurs in the water pressure balance in the pipeline and the water pressure on the downstream side rises abnormally, the check valve closes and the water pressure on the downstream side overcomes the biasing force of the elastic spring in the bypass valve to push back the valve body, and The crimp with the valve box valve seat surface of is released. Therefore, the bypass passage in the check valve is opened,
The water pressure on the downstream side, which is rapidly increased by connecting the downstream side and the upstream side, is released to the upstream side in the check valve and is rapidly relieved. When the abnormal condition is resolved and the check valve opens again, the water pressure on the downstream side also returns to normal, so the urging force of the elastic spring wins again and the valve body is crimped to the valve box seat surface of the check valve. Bypass channel closes.

[0013]

1 (A) and 1 (B) are a horizontal sectional view (A) and a vertical sectional view (B) of an embodiment of the present invention. Further, FIG. 2 is a longitudinal sectional view showing a state in which the check valve is open (the bypass valve is open) in the same embodiment. In each of the drawings, the check valve 1 is quoted from a commonly used known structure, but it goes without saying that the check valve may be configured in any other way. In the case of this drawing, the check valve 1 is provided with a bypass flow passage 12 in a valve box 11, a downstream side opening 13 and an upstream side opening 15 are respectively opened, and communication between them is performed by opening and closing a valve box valve seat 14. Is interrupted by. The check valve 1 itself is opened and closed by pressing the two valve elements 17 pivotally supported by the valve shaft 16 by the water force (arrow) from below (upstream side) in FIG. The water is rotated upward by overcoming the urging force of and the water forms a steady flow in the opened pipe.

The bypass valve 2 is in the closed state in FIG. 1, and the valve body 22 is attached to the valve box valve seat 14 of the bypass passage of the check valve 1.
The valve seat surface 21 of is crimped. An elastic spring 29 intervenes between the back surface 23 of the valve body 22 and the front surface 25-1 of the engagement box 25 to urge the head of the valve body 22 in the closing direction. A gap S2 (between the valve body shaft stopper 24-1 and the front and rear surfaces 25-2 of the engagement box 25) so that the valve body shaft 24 can move in the engagement box 25 in accordance with a change in balance between water pressure and elastic spring pressure. ),
A gap S1 (the rear end 24-2 of the valve body shaft and the rear face of the engagement box are provided respectively. The valve rod 27 provided with the engagement box 25 at the tip has a male screw 27-1 threaded in the middle to form a valve box. The position is specified by screwing with the female screw 26-1 screwed on 26. Therefore, the position of the valve rod can be arbitrarily changed by a manual operation of rotating the handle 28 at the rear end.

FIG. 2 shows a state in which the check valve 1 is closed due to an increase in the water pressure on the downstream side due to an abnormality in the flow path. Along with the operation of the check valve, the water pressure on the downstream side also overcomes the biasing force of the elastic spring 29 in the bypass valve 2 to push the valve body 22 back to the right in the drawing, and the valve box seat of the check valve bypass passage. Since the valve seat surface 21 that has been crimped with 14 is separated, the downstream side opening 13 and the upstream side opening 15 of the bypass flow path 12 are communicated with each other and the closed state is opened, so that the increased water pressure on the downstream side escapes to the upstream side. Then falls rapidly.

FIG. 3 is a diagram for explaining the effect of the handle, and shows the case where the bypass flow passage is forcibly opened with the check valve 1 closed in the same embodiment. Such cases appear when draining water on the downstream side, and are always accompanied by opportunities for construction and repair. Bypass valve 2
When the handle 28 is rotated, the valve rod 27 moves in the axial direction by itself because the internal thread of the valve box to be screwed is immovable, and the stopper 24-1 of the valve body axis is moved in the engaging box moving together. The gap S2 is lost by coming into contact with the back surface 25-2 of the front surface. That is, by operating the handle, the valve body 22 is forcibly separated from the valve box valve seat of the bypass flow passage of the check valve to open the flow passage, and the water on the downstream side can be drained to the downstream side.

FIG. 4 shows another embodiment of the present invention. Instead of the valve body 22 and the valve body shaft 24 of the previous example (FIG. 1), a swing valve body 32 is rotatably supported with a pin 31 as a fulcrum. When,
The push rod 33 is crimped to the back surface 34 of the swing valve body 32.

FIG. 5 shows still another embodiment, in which the check valve is provided with a downstream side opening 13 and an upstream side of the check valve at the tip of the valve rod 27 instead of the valve body 22, the valve body shaft 24 and the engagement box 25. A cylindrical casing 43 penetrating the downstream side opening 41 and the upstream side opening 42 which respectively communicate with the port 15 is attached, and a spherical valve element 44 is inserted into the casing 43, and an elastic spring for urging the spherical valve element 44 from the rear side. This is a configuration in which 45 is inserted. It is only necessary to judge the suitability according to the application and select the most suitable configuration.

[0019]

As described above, the present invention operates in conjunction with the operation of the check valve, and has the effect of opening when the water pressure on the downstream side abnormally increases to prevent the occurrence of water hammer. . In addition, since the opening / closing operation is automatically performed, it is possible to prevent the accident of partial breakage of the flow passage by covering all the complicated nets of the flow passage, without the need for a person such as a monitor. In addition, when the abnormal situation is resolved, the original state is automatically restored and synchronized with the operation of the check valve, so that there is an effect of guaranteeing the maintenance of the flow path without the need for manpower.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view (A) and a vertical sectional view (B) of an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing another aspect of the same embodiment.

FIG. 3 is a vertical sectional view showing still another aspect of the same embodiment.

FIG. 4 is a vertical sectional view showing another embodiment.

FIG. 5 is a vertical sectional view showing still another embodiment.

FIG. 6 is a cross-sectional view showing an example of a conventional technique.

[Explanation of symbols]

 1 Check valve 2 Bypass valve 11 Valve box 12 Bypass flow path 13 Downstream port 14 Downstream valve seat 15 Upstream port 21 Valve seat surface 22 Valve body 23 Back surface 24 Valve body shaft 24-1 Stopper 24-2 Rear end 25 Engagement box 25-1 Front surface 25-2 Front rear surface 26 Valve box 27 Valve rod 28 Handle 29 Elastic spring 31 Pin 32 Swing valve disc 33 Push rod 34 Back face (Swing valve disc) 41 Downstream opening 42 Upstream opening 43 Casing 44 Spherical valve element 45 Elastic spring S1 clearance (in engagement box) S2 clearance (in engagement box)

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 22, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

In the bypass valve of the check valve according to the present invention, when the water pressure in the pipeline is flowing at a normal level, the valve body is biased from the rear by the elastic spring and the valve seat surface thereof is a check valve. Since it is crimped to the valve box valve seat surface of the bypass passage, the passage is closed and the communication between the downstream side and the upstream side in the check valve is cut off. If an abnormality occurs in the water pressure balance in the pipeline and the water pressure on the downstream side rises abnormally, the check valve closes and the water pressure on the downstream side overcomes the biasing force of the elastic spring in the bypass valve to push back the valve body, and The crimp with the valve box valve seat surface of is released. Therefore, the bypass passage in the check valve is opened,
The water pressure on the downstream side, which is rapidly increased by connecting the downstream side and the upstream side, is released to the upstream side in the check valve and is rapidly relieved. When the abnormal condition is resolved and the check valve opens again, the water pressure on the downstream side also returns to normal, so the urging force of the elastic spring wins again and the valve body is crimped to the valve box seat surface of the bypass passage . Bypass channel closes.

Claims (4)

[Claims] 1. A bypass valve of a check valve, which is connected to a check valve interposed in a flow path and opens and closes a bypass flow path communicating with an upstream side and a downstream side, communicates with a bypass flow path of the check valve. A bypass valve for a check valve, comprising a valve body which opens and closes a valve box valve seat so as to be able to move forward and backward, and an elastic spring which constantly urges the valve body in a closing direction is provided so as to expand and contract. 2. A valve box valve seat 14 is provided at a downstream side opening 13 of a bypass passage 12 provided in the valve box 11 of the check valve 1 and communicating with the upstream side and the downstream side, and the valve box valve seat 14 is opened and closed. The bypass valve 2 includes a valve body 22 having a valve seat surface 21 at the tip of which is attached to and detached from the valve box valve seat, and a valve body shaft 2 fixed to a back surface 23 of the valve body 22.
4. Engagement box 2 that holds the rear end of the valve body shaft 24 so that it can move back and forth.
5, a valve rod 27 fixed to the rear end of the engagement box 25 and screwed forward and backward with the valve box 26, a handle 28 attached to the outside of the valve box at the rear end of the valve rod 27, and the engagement box 25 Front 25-1
And a resilient spring 29 interposed between the back surface 23 of the valve body and a bypass valve of the check valve. 3. The valve body 22 and the valve body shaft 24 according to claim 1.
Instead of the above, a non-return valve bypass valve comprising a swing valve body 32 rotatably supported with a pin 31 as a fulcrum, and a push rod 33 crimped to the back surface of the swing valve body 32. 4. A downstream side opening 41 communicating with the downstream side opening 13 and the upstream side opening 15 of the check valve at the tip of a valve rod 27 instead of the valve body 22, the valve body shaft 24 and the engaging box 25, respectively. A cylindrical casing 43 penetrating the upstream side opening 42 is attached, and a spherical valve body 44 and an elastic spring 45 for urging the spherical valve body 44 from the back are inserted into the casing 43. Stop valve bypass valve.