JP2010009330A - Decompression device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decompression device wherein there is no occurrence of chattering nor excessive increase of secondary side pressure especially even if a use amount of water is significantly reduced. <P>SOLUTION: In this decompression device, a direct acting decompression valve 3 wherein responsiveness of an opening/closing valve in a small flow rate area is excellent, wherein the chattering does not occurs, and wherein the secondary side pressure does not increase as compared to a set pressure for valve closing, because the direct acting decompression valve has a configuration wherein a valve element is directly driven, and a pilot type decompression valve 4 suitable for water supply of a large flow rate are plumbed in parallel, and the set pressure of the direct acting decompression valve 3 is set to higher than a set pressure of the pilot type decompression valve 4. Thereby, the pilot type decompression valve 4 is certainly precedingly closed, the direct acting decompression valve 3 is in the middle of valve opening as the whole decompression device 1 even when the secondary side pressure increases at that time, so that its pressure is discharged from a bibcock such as a faucet during use installed to an end of a water supply pipe 2, and thereafter the direct acting decompression valve 3 is closed. Thereby, because the whole decompression device 1 is fully closed, the occurrence of the chattering or the excessive increase of the secondary side pressure is nil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pressure reducing device that can always maintain a secondary side pressure below a set pressure in water supply facilities such as water supply.

Conventionally, in water supply facilities such as water supply, the amount of water used is significantly different between daytime and nighttime, and the secondary pressure of the pressure reducing valve installed in the pipeline can be set to be suitable for daytime use. Because the amount of water used at night is significantly reduced, excessive water pressure is applied to the secondary side of the pressure reducing valve, which can lead to water leaking from defective parts such as secondary side pipe connections and water supply end faucets. I have been invited.
In order to prevent such inconvenience, for example, as disclosed in Patent Document 1, a pressure control valve that automatically switches the secondary side pressure to high and low two stages according to the amount of water used on the secondary side is known.
This pressure control valve adjusts the opening degree of the main valve body by utilizing the differential pressure between the primary side pressure and the secondary side pressure, and introduces the primary side pressure into the pressure chamber and Combining a pilot valve set to a high and low two-stage pressure with a switching valve that opens and closes according to the opening degree of the main valve body in combination with the secondary side according to changes in water usage Adjust the side pressure in two steps, high and low.
Japanese Utility Model Publication 4-18017

However, since the pressure regulating valve is a pilot operated type that opens and closes the main valve body by one of two types of pilot valves, the main valve body of the main body is fully closed even if the pilot valve is closed. There is a time difference, and during this time, the secondary pressure rises above the set value, so the above-mentioned problems as in the prior art cannot be completely eliminated.
In addition, when the amount of water used is small, the opening of the main valve element becomes extremely small, and chattering that causes noise and vibration may occur due to repeated opening and closing valves in a very small opening state. It was.
Accordingly, an object of the present invention is to provide a pressure reducing device that does not cause chattering and excessively increase the secondary pressure even when the amount of water used is significantly reduced.

  In view of the above problems, the pressure reducing device of the present invention has a direct acting pressure reducing valve and a pilot pressure reducing valve arranged in parallel, and the set pressure of the direct acting pressure reducing valve is set higher than the set pressure of the pilot pressure reducing valve. It is characterized by that.

In short, since the pressure reducing device according to the present invention directly drives the valve body, the responsiveness of the on-off valve in the small flow rate region is good, and the secondary side pressure does not rise above the set pressure when chattering occurs or when the valve is closed. A direct acting pressure reducing valve and a pilot pressure reducing valve suitable for large-volume water supply are connected in parallel, and the set pressure of the direct acting pressure reducing valve is set higher than the set pressure of the pilot pressure reducing valve. Even if the pressure reducing valve closes first and the secondary pressure rises at that time, the pressure reducing device as a whole is open and the pressure is attached to the end of the water supply pipe. By discharging from a faucet or other faucet and then closing the direct acting pressure reducing valve, the entire pressure reducing device is fully closed, so there is no chattering or excessive increase in secondary pressure. is there.
Therefore, according to the present invention, even when the amount of water used changes drastically during the daytime and nighttime, the secondary side pressure can always be maintained at a set pressure or less, and water can be supplied as in the conventional case. Since excessive water pressure is not applied to the secondary side, it is possible to prevent water leakage from defective parts such as pipe connections and faucets on the secondary side and other adverse effects on other water supply equipment. Its practical effects are great.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a simplified diagram showing an example of a decompression device according to the present invention.
The pressure reducing device 1 is configured by connecting a direct acting pressure reducing valve 3 and a pilot pressure reducing valve 4 in parallel in a water supply pipe 2 such as a water supply.
The direct acting pressure reducing valve 3 and the pilot pressure reducing valve 4 are conventional ones, and the configuration thereof is not limited at all. However, the set pressure of the direct acting pressure reducing valve 3 is higher than the set pressure of the pilot pressure reducing valve 4. It is set.
The diameters of the direct acting pressure reducing valve 3 and the pilot pressure reducing valve 4 are determined in consideration of the maximum flow rate of the water supply pipe 2 to which they are piped. The same or the direct acting pressure reducing valve 3 may have a smaller diameter than the pilot pressure reducing valve 4.

The direct-acting pressure reducing valve 3 includes a drive unit that operates by sensing the secondary side pressure, and a valve body that opens and closes a flow path provided in the valve box 3a in connection with the drive unit. The side pressure is maintained at a certain pressure lower than the primary side pressure, and the inlet and outlet of the flow path opened on the left and right sides of the valve box 3a are connected to the primary side 2a and the secondary side 2b of the water supply pipe line 2 respectively. Connected to.
In general, the direct-acting pressure reducing valve is not limited to the example shown in the figure, and because of its structure, the seat diameter is smaller than that of the pilot-type reducing valve, and it is difficult to supply a large amount of water. The valve body has a characteristic that the water consumption on the secondary side is good in general in the flow range from a very small opening to a full opening, and the secondary pressure in the full flow range can be controlled well. Due to this characteristic, chattering in which the valve body repeatedly strikes the valve seat with a very small opening degree close to the valve closing hardly occurs.

The pilot type pressure reducing valve 4 is composed of a pilot valve 4b composed of a small diameter pressure reducing valve connected between the primary side and the secondary side, and connected to the pilot valve 4b. It consists of a drive unit that controls the opening of the valve body, and a main body 4a that is connected to the drive unit and has a main valve body that opens and closes the flow path, and the secondary pressure is lower than the primary pressure. The inlet and the outlet of the flow path established on the left and right sides of the main body 4a are connected to the primary side 2a and the secondary side 2b of the water supply pipe 2.
In general, the pilot type pressure reducing valve is not limited to the example shown in the figure, and its structure makes the seat diameter larger than that of the direct acting type pressure reducing valve and can supply a large amount of water. When the valve opens, the secondary pressure rapidly reaches the set pressure and closes, and chattering may occur due to the repeated opening and closing of the valve. Even if the pilot valve closes, the main valve of the main body will close. Due to the time difference that occurs until this time, the secondary pressure rises above the set pressure.

In the pressure reducing device 1 configured as described above, the direct acting pressure reducing valve 3 and the pilot pressure reducing valve 4 are piped in parallel, and the set pressure of the direct acting pressure reducing valve 3 is set to the set pressure of the pilot pressure reducing valve 4. By setting the pressure higher than this, the disadvantages of the direct acting pressure reducing valve 3 and the pilot pressure reducing valve 4 can be compensated for each other, and the secondary pressure can always be kept below the set pressure.
That is, in the small flow rate region, only the direct-acting pressure reducing valve 3 is operated to supply water while maintaining the secondary side pressure below the set pressure, and the secondary side pressure becomes large below the set value of the direct acting pressure reducing valve 3. In the flow rate range, the pilot pressure reducing valve 4 is also operated, and the secondary pressure is maintained below the set pressure in cooperation with the direct acting pressure reducing valve 3 to supply water.

Below, the effect | action of the decompression device 1 is demonstrated.
When the amount of water used on the secondary side is small, such as at night (until the amount of water used increases and the secondary side pressure drops from the set pressure of the direct acting pressure reducing valve 3 to the set pressure of the pilot pressure reducing valve 4) Of course, the pilot pressure reducing valve 4 is closed, and only the direct acting pressure reducing valve 3 is opened to supply water to the secondary side end of the water supply pipe 2, and the secondary pressure is lower than the primary pressure. It is kept at a certain pressure.
In addition, since only the direct-acting pressure reducing valve 3 is operated to supply water in the small flow rate region, chattering is prevented by good secondary pressure control in the small flow rate region, which is a characteristic of the direct acting pressure reducing valve. Does not occur.

When the secondary pressure drops below the set pressure of the pilot pressure reducing valve 4 due to an increase in the amount of water used from the small flow rate range such as during the daytime, the pilot pressure reducing valve 4 is also opened, and both pressure reducing valves The secondary side pressure is maintained at a certain constant pressure lower than the primary side pressure by 3 and 4.
As described above, when the amount of water used decreases again from the large flow rate range where both the pressure reducing valves 3 and 4 are open and the secondary pressure rises above the set pressure of the pilot pressure reducing valve 4, the pilot pressure reducing valve 4 Close the valve.
At this time, the secondary pressure once rises due to the above characteristics of the pilot pressure reducing valve 4, but since the direct acting pressure reducing valve 3 is still open, the increased pressure generated by the pilot pressure reducing valve 4 It is discharged from a faucet such as a faucet in use attached to the end of the pipe line 2.

In the case of water supply by the operation of only the direct acting pressure reducing valve 3 while the pilot pressure reducing valve 4 is closed, chattering does not occur as described above.
Then, when the amount of water used is completely lost such as at midnight from the above situation (small flow rate range), the direct acting pressure reducing valve 3 is also closed, but the direct acting pressure reducing valve is different from the pilot pressure reducing valve in the drive unit. Since the main valve is directly driven by this, the secondary side pressure is not increased by the valve closing.

It is a simplified diagram showing an example of a decompression device.

Explanation of symbols

3 Direct acting pressure reducing valve 4 Pilot pressure reducing valve

Claims (1)

  A pressure reducing device, wherein a direct acting pressure reducing valve and a pilot pressure reducing valve are connected in parallel, and a set pressure of the direct acting pressure reducing valve is set higher than a set pressure of the pilot pressure reducing valve.

Images