JPH07190219A - Check valve device - Google Patents

Abstract

PURPOSE:To simplify leakage inspection of inside check valve mechanisms from outside by providing the check valve mechanisms between a primary side chamber and an intermediate chamber and the intermediate chamber and a secondary side chamber, communicating the primary side chamber and the intermediate chamber and the outside to each other by a drain passage provided with an opening and closing valve mechanism and communicating the intermediate chamber and the secondary side chamber to each other by a communicating passage provided with an opening and closing valve mechanism. CONSTITUTION:A check valve mechanism 10 is provided between a primary side chamber 2 and an intermediate chamber 4, and a check valve mechanism 20 is provided between the intermediate chamber and a secondary side chamber 3. Thereafter, an opening and closing valve mechanism 32 is provided in a drain passage 31 communicating the primary side chamber 2 and outside, and an opening and closing valve mechanism 36 is provided in a drain passage 34 communicating the intermediate chamber 4 and outside, too. Additionally, a communicating passage 35 communicating the intermediate chamber 4 and the secondary side chamber 3 is provided, and an opening and closing valve mechanism 38 is provided in this communicating passage 35, too. It is possible to easily inspect respective existence of leakage about the two check valve mechanisms from outside by selectively opening and closing these opening and closing valve mechanism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double check valve type check valve device provided in the middle of piping of a water supply facility. More specifically, the present invention relates to a check valve device of a double check valve type, which is capable of externally inspecting a check valve mechanism incorporated therein for leakage.

[0002]

2. Description of the Related Art Generally, a water supply facility for a building such as a high-rise building is provided with a water storage tank between the water main and the water faucet at the end, and water supplied from the water main is temporarily stored in the water storage tank. It is configured to store water and then supply it to the end tap.

However, such a water supply facility has a problem that the water in the water storage tank is troublesome to manage, such as periodically cleaning the water storage tank. In order to prevent such inconvenience, adoption of water supply equipment in which the above-mentioned water main is directly connected to the water faucet at the end is being considered. Although such a type of water supply system is common in low-rise housing, etc., if such a type of water supply system is adopted in high-rise buildings, condominiums, etc., there will be a problem of backflow when water is cut off.

That is, the water pipe of such a high-rise building has a large drop, and if the water pressure in the water main falls due to a break in water or the like, a large negative pressure is generated due to a large head pressure, and water is discharged from the water faucet at the end. Will flow backwards, and the inside of the water mains will be contaminated. Conventionally, in order to prevent the generation of such a negative pressure, a vacuum breaker is provided at a key point of the piping, and when a negative pressure is generated, it is possible to suck air from the vacuum breaker and prevent the generation of the negative pressure. Has been done. However, in the water facilities of high-rise buildings,
Installation of such a vacuum breaker is not enough, and more reliable backflow prevention equipment must be provided.

In order to prevent the backflow of water facilities such as high-rise buildings, a check valve device is provided in the middle of the pipe. In order to increase the reliability of such a check valve device, two check valve mechanisms are arranged in series inside, so that even if a leak occurs in one check valve mechanism, a backflow does not occur. It is configured.

However, even in such a double check valve type check valve device, it is necessary to regularly inspect.
However, it is not possible to inspect the inside of such a check valve device from the outside, and in many cases, the check valve device must be disassembled to inspect the deterioration of the packing inside. , Requires a lot of effort and was inefficient.

[0007]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and has a double check valve mechanism inside and both of the two check valve mechanisms inside from the outside. The present invention provides a check valve device capable of easily inspecting for leaks.

[0008]

The check valve device of the present invention comprises:
The valve box has a primary chamber, a secondary chamber, and an intermediate chamber formed therebetween. And, between the primary chamber and the intermediate chamber, and between the intermediate chamber and the secondary chamber, the first chamber is provided.
And a second check valve mechanism.

A first drain passage communicating with the primary chamber and the outside is formed, and a first opening / closing valve mechanism is provided in the first drain passage. In addition, a second drain passage that connects the above intermediate chamber and the outside is formed,
A second opening / closing valve mechanism is provided in the first drain passage. Further, a communication passage that connects the intermediate chamber and the secondary chamber is formed, and a third opening / closing valve mechanism is provided in this communication passage.

[0010]

When inspecting the check valve device of the present invention, the on-off valve and the like arranged on the upstream side of the check valve device are closed to reduce the water pressure on the upstream side of the check valve device. Let Then, the third on-off valve mechanism is opened, and the first on-off valve mechanism is opened. Thereby, the water in the primary side chamber is discharged through the first drain passage, and the water head pressure generated in the pipe connected to the secondary side chamber side acts on the intermediate chamber through the communication passage. . In this case, if the first check valve mechanism is not leaking, after the water in the primary side chamber and the pipe connected to the primary side chamber is discharged,
The discharge of water from the first drain passage is stopped. On the other hand, when leakage occurs in the first check valve mechanism, water in the secondary side pipe flows into the intermediate chamber through the communication passage. Water leaks to the primary side chamber, and water continues to be discharged from the first drain passage. Therefore, the presence / absence of leakage of the first check valve mechanism can be determined from the outside.

Next, the third opening / closing valve mechanism is closed and the second opening / closing valve mechanism is opened. As a result, the water in the intermediate chamber is discharged from the second drain passage. When there is no leakage in the second check valve mechanism, the discharge of this water is stopped, but when there is leakage in this second check valve mechanism, the inside of the secondary side pipe is Since this water flows into the intermediate chamber, the discharge of water from this second drain passage does not stop. Therefore, the leakage of the second check valve mechanism can be determined from the outside.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is a check valve device for preventing backflow of water facilities. Reference numeral 1 in the figure is a valve box of the check valve device, and a primary side chamber 2 on the inflow side and a secondary side chamber 3 on the outflow side are formed in the valve box. In addition, in this valve box 1,
An intermediate chamber 4 is formed between the primary side chamber 2 and the secondary side chamber 3.

A first check valve mechanism 10 is built in between the primary chamber 2 and the intermediate chamber 4, and a second check valve mechanism 10 is provided between the intermediate chamber 4 and the secondary chamber 3. Check valve mechanism 2
0 is built in.

The above-mentioned first check valve mechanism 10 is constructed as follows. That is, the valve seat 11 is provided to connect the primary side chamber 2 and the intermediate chamber 4 to each other. And
The valve body 12 is seated on the valve seat 11 from the downstream side, that is, the intermediate chamber 4 side, and allows only the flow in the direction from the primary side chamber 2 to the intermediate chamber 4 and blocks the flow in the opposite direction. Is configured. A valve shaft 13 is provided so as to project upward from the valve body 12, and the valve body 12 is biased by a spring 14 in the valve closing direction. Also,
The upper end of the valve shaft 13 is vertically slidably guided by a guide member 15.

A lid 16 is attached to the valve box 1 above the first check valve mechanism 10, and a stopper member 17 is screwed onto the upper end of the lid 16. The lower end of the stopper member faces the upper end of the valve shaft 13, and when the valve body 12 opens and the valve shaft 13 rises, the lower end of the stopper member 17 moves the valve shaft. Thirteen
It is configured to contact the upper end of the valve body 12 to regulate the opening degree of the valve body 12. Then, the maximum opening degree of the valve body 12 can be adjusted by screwing the stopper member 17 up and down.

The second check valve mechanism 20 is provided obliquely with respect to the valve box 1 in order to reduce the flow path resistance. The second check valve mechanism 20 also has the same structure as the first check valve mechanism 10 described above, and is provided with a valve seat 21 that connects the intermediate chamber 4 and the secondary side chamber 3 to each other. The valve body 22 is seated on the seat 21 from the secondary side chamber 3 side, and is configured to allow only the flow from the intermediate chamber 4 to the secondary side chamber 3. Further, the valve body 22 has a valve shaft 23.
The valve shaft 23 is slidably guided by a guide member 25. The valve body 22 is guided by a spring 24 in the valve closing direction. 26
Is a lid, and the lid 26 of the second check valve mechanism 20.
No stopper member is provided in the.

The first side chamber 2 has a first portion at the bottom thereof.
Of the first drain passage 3
1 is open to the atmosphere. A first opening / closing valve mechanism 32 is provided in the first drain passage 31.
The on-off valve mechanism 32 is a small cock and is opened and closed by manually operating the handle 33.

A second drain passage 34 is communicated with the bottom of the intermediate chamber 4, and the second drain passage 34 is open to the atmosphere. A second opening / closing valve mechanism 36 is provided in the second drain passage 34. The on-off valve mechanism 36 is a small cock and has a handle 37.
It is opened and closed by manually operating.

Further, in the valve box 1, the above intermediate chamber 4 is provided.
A communication passage 35 that communicates between the secondary side chamber 3 and the secondary side chamber 3 is formed. Then, in the middle of this communication passage 35, the on-off valve mechanism 3
8 are provided. The on-off valve mechanism 38 is of a small needle valve type and is opened and closed by rotating the valve shaft with a driver or the like.

Next, the operation of the above check valve device will be described. In a normal state, the first to third opening / closing valve mechanisms 32, 36, 38 are all closed. Then, the water flows through the primary side chamber 2, the intermediate chamber 4, and the secondary side chamber 3 described above. At this time, the first check valve mechanism 10 and the second check valve mechanism 20 are opened by water pressure to allow water to flow.

When water supply is cut off and the water supply main side, that is, the primary side chamber 2 side of the check valve device becomes low in pressure, the first and second check valve mechanisms 10 and 20 described above are operated. The valve is closed by the urging force of the springs 14 and 24 and the water pressure to prevent backflow from the piping on the secondary side chamber 3 side.

Next, when inspecting this check valve device, the on-off valve (not shown) and the like arranged upstream of this check valve device are closed, and this check valve device is closed. Reduce the water pressure on the upstream side. Then, the above-mentioned third opening / closing valve mechanism 38
And the first opening / closing valve mechanism 32 is opened. As a result, the water in the primary side chamber 2 is discharged through the first drain passage, and the hydraulic head pressure generated in the pipe connected to the secondary side chamber 3 side is the intermediate chamber through the communication passage 35. Act on. In this case, when the first check valve mechanism 10 is not leaking, after the water in the primary chamber 2 and the pipe connected to the primary chamber 2 is discharged,
The drainage of water from the drain passage 31 is stopped. On the other hand, if there is a leak in the first check valve mechanism 10,
Since the water in the secondary side pipe flows into the intermediate chamber 4 via the communication passage 35, the water leaks from the first check valve mechanism 10 to the primary side chamber 2, and the water flows from the first drain passage 31. Water continues to drain. Therefore, the presence / absence of leakage of the first check valve mechanism 10 can be determined from the outside.

Next, the third opening / closing valve mechanism 38 is closed and the second opening / closing valve mechanism 36 is opened. As a result, the water in the intermediate chamber 4 is discharged from the second drain passage 34.
If no leakage has occurred in the second check valve mechanism 20,
Although the discharge of this water is stopped, this second check valve mechanism 20
When there is a leak, the water in the secondary pipe flows into the intermediate chamber 4, so the discharge of water from the second drain passage 34 does not stop. Therefore, leakage of the second check valve mechanism 20 can be determined from the outside.

In this way, it is possible to externally inspect both the first check valve mechanism 10 and the second check valve mechanism 20 for leakage from the outside.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, the structures of the first and second check valve mechanisms described above are not necessarily limited to those of the above-described embodiments.

[0026]

As described above, the present invention relates to the first and second check valve mechanisms built in the valve box by selectively opening and closing the first to third opening / closing valve mechanisms. The presence or absence of leakage can be inspected easily and efficiently from the outside.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a check valve device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Valve box 2 ... Primary side chamber 3 ... Secondary side chamber 4 ... Intermediate chamber 10 ... 1st check valve mechanism 20 ... 2nd check valve mechanism 31 ... 1st drain passage 32 ... 1st opening / closing valve mechanism 34 ... Second drain passage 35 ... Communication passage 36 ... Second on-off valve mechanism 38 ... Third on-off valve mechanism

Claims (1)

[Claims] 1. A valve box, an inflow-side primary chamber formed in the valve box, an outflow-side secondary chamber formed in the valve box, and the primary chamber in the valve box. An intermediate chamber formed between the secondary side chamber and the first check valve mechanism, which is provided between the primary side chamber and the intermediate chamber and allows only a flow from the primary side chamber to the intermediate chamber; A second check valve mechanism which is provided between the intermediate chamber and the secondary chamber and allows only a flow from the intermediate chamber to the secondary chamber, and the primary check chamber which communicates with the bottom of the primary chamber. A first drain passage communicating with the outside, a first opening / closing valve mechanism provided in the first drain passage, and a second communicating with the bottom of the intermediate chamber and communicating the intermediate chamber with the outside. Drain passage, a second opening / closing valve mechanism provided in the second drain passage, and the intermediate chamber and the secondary chamber are connected to each other. A check valve device comprising: a communication passage that communicates with a third opening / closing valve mechanism provided in the middle of the communication passage.