JPH07122467B2 - Check valve device - Google Patents

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 in view of the above circumstances. It has a double check valve mechanism inside and can easily prevent leakage of the check valve mechanism inside from the outside. It provides a check valve device that can be inspected.

[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 drain passage communicating with the outside is formed at the bottom of the intermediate chamber, and an opening / closing valve is provided in the drain passage.

[0009]

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 opening / closing valve of the drain passage is opened. By opening the on-off valve, the water in the intermediate chamber is discharged, but if there is no leakage in the check valve mechanism inside, the outflow of water from the drain passage is stopped in a short time. However, when leakage occurs in the internal second check valve mechanism, water on the downstream side of the check valve device leaks into the intermediate chamber via the second check valve mechanism. , The discharge of water from this drain passage does not stop. Therefore, it is possible to easily inspect from the outside whether or not the check valve mechanism inside is leaking from the state of the water discharged from the drain passage.

[0010]

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 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.

A drain passage 31 is communicated with the bottom of the intermediate chamber 4, and the drain passage 31 is open to the atmosphere. An opening / closing valve mechanism 32 is provided in the drain passage 31. The on-off valve mechanism 32 is a small cock and is opened and closed by manually operating the handle 33.

Next, the operation of the above check valve device will be described. In a normal state, the open / close valve mechanism 32 is 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 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.

When the check valve device is inspected, the on-off valve (not shown) provided in the pipe on the primary chamber 2 side is closed to reduce the water pressure on the primary side. As a result, the first and second check valve mechanisms 10 and 20 are closed. Then, in this state, the above handle 3
3 is operated to open the opening / closing valve mechanism 32. By opening the opening / closing valve mechanism 32, the water in the intermediate chamber 4 is discharged through the drain passage 31.

In this case, when there is no leakage in the second check valve mechanism 20 described above, after the water in the intermediate chamber 4 is discharged, the discharge of water from the drain passage 31 is stopped. However, when the second check valve mechanism 20 is leaking, the water in the pipe on the secondary side chamber 3 side flows into the intermediate chamber 4, so that the water from the drain passage 31 is discharged. Discharge continues. Therefore, it is possible to determine whether or not the second check valve mechanism 20 is leaking only by externally observing whether or not the discharge of water from the drain passage 31 is stopped.

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.

[0021]

As described above, according to the present invention, simply by opening and closing the opening / closing valve mechanism of the drain passage communicating with the intermediate chamber, it is possible to easily inspect the internal leakage from the outside based on the state of discharge of water from the drain passage. Therefore, the inspection work can be performed easily and efficiently.

[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]

 1 ... Valve box 2 ... Primary side chamber 3 ... Secondary side chamber 4 ... Intermediate chamber 10 ... First check valve mechanism 20 ... Second check valve mechanism 31 ... Drain passage 32 ... Open / close 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 side 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 that is provided between the intermediate chamber and the secondary chamber and allows only the flow from the intermediate chamber to the secondary chamber; and the intermediate chamber that communicates with the bottom of the intermediate chamber. A check valve device comprising: a drain passage communicating with the outside; and an on-off valve mechanism provided in the drain passage.