KR100727622B1 - A pressure reducing valve for fire fighting - Google Patents

Abstract

A pressure reducing valve for fire fighting is provided to maintain the effects of pressure reduction in a main piping always by allow water to move from a high pressure side to a low pressure side of a pressure reduction valve when pressure reduction is necessary. The pressure reducing valve for fire fighting includes a main valve(12), an ejector(16), a pilot valve(14) and a relief pilot valve(20). The main valve(12) includes a first inflow chamber(122), a second outflow chamber(124) and a diapharagm chamber(126). When the pressure of the outflow chamber(124) is higher than a second set up pressure, the relief pilot valve(20) makes a small amount of water discharged from the outflow chamber(124) to make the pressure of the outflow chamber(124) lower than a second set up pressure.

Description

PRESSURE REDUCING VALVE FOR FIRE FIGHTING

1 is a schematic cross-sectional view showing the structure of a conventional fire reducing valve.

Figure 2 is a schematic piping diagram showing the structure of a pressure reducing valve for fire in accordance with an embodiment of the present invention.

<Brief description of the major symbols in the drawings>

10: fire fighting pressure reducing valve 12: main valve

122: inlet chamber 124: outlet chamber

126: diaphragm chamber 14: pilot valve

16: ejector 18: strainer

20: relief pilot valve 30: outlet

The present invention relates generally to fire-reducing pressure reducing valves of sprinkler equipment or indoor fire hydrant systems, and more particularly, to inlet chambers of fire-reducing pressure-reducing valves even when the fire water is stagnant in a pressure-reducing valve for reducing pressure of a high-pressure fire water to a constant pressure. And a pressure reducing valve for fire fighting, which is configured to maintain a pressure difference between the discharge chamber and the discharge chamber within a set value range.

In general, indoor sprinkler equipment and indoor fire hydrant systems in fire fighting systems must satisfy the regulations that the fire pressure at each end should not exceed 12kg / cm2 (spring cooler) and 7kg / cm2 (fire hydrant), respectively. . Since water pressure above this specified pressure is normally supplied through a pump, for example, before each sprinkler and pre-fired pipe supply, the pressure must be reduced through a decompression device, and then fire water of a reference pressure according to legal regulations must be supplied.

For this purpose, it is common to apply a pressure reducing valve immediately before the sprinkler or pipe before the fire hydrant at each end. 1 shows an example of a pressure reducing valve conventionally used. The illustrated pressure reducing valve 10 is a type of the OCV Pressure Reducing valve Series 127 series manufactured by OCV Control Valves, for example. The diaphragm-type main valve 12 and the pilot valve which flow out after being decompressed after being supplied with high pressure water 14, and the ejector 16 has a configuration. At the time of supply of the fire water, high pressure water is supplied to the primary side of the main valve 12, that is, the inflow chamber 122, in the operation of the pressure reducing valve 10, and the central diaphragm is supplied by the high pressure of the supplied water. The decompressed water flows out to the secondary side, that is, toward the outlet chamber 124 while moving and opening.

It is connected between the outlet chamber 124 and the diaphragm chamber 126 on the upper part of the diaphragm by the pilot valve 14, and the inlet chamber 122 and the diaphragm chamber 126 are also ejectors 16 and The strainers 180 are connected to each other. If the pressure of the outlet chamber 124 is set to be equal to the water pressure prescribed in the fire law, the pilot valve 14 maintains a constant opening degree, and passes through the pilot valve 14 from the inlet chamber 122. Although water flows into the outlet chamber 124, the water pressure of the water prevents the inflow / outflow of water from the diaphragm chamber 126. In this case, since the main valve 12 maintains a constant opening degree, water of a constant water pressure is supplied through the main valve 12.

If the pressure of the outlet chamber 124 is less than the set pressure, the pilot valve 14 detects the low pressure of the outlet chamber 124 and is further opened, thereby removing the pilot valve 14 from the diaphragm chamber 126. Water flows out through the outflow chamber 124 through it, and thus the diaphragm is lifted up so that the main valve 12 is opened slightly further so that more water flows from the inflow chamber 122 to the outflow chamber 124. The pressure in the chamber 124 may be increased to the set pressure.

If the pressure of the outflow chamber 124 is higher than the set pressure, the pilot valve 14 detects the high pressure of the outflow chamber 124 and automatically closes slightly. In this case, since water is supplied from the inlet chamber 122 to the diaphragm chamber 126 and a small amount of water is supplied, the main valve 12 is slightly closed, and thus the pressure of the outlet chamber 124 may be dropped to become the set pressure. .

As described above, when the pressure reducing valve as shown in FIG. 1 is applied, an advantage of reducing the supply pressure of the fire water to the set pressure could be provided. However, in general, the fire fighting pipe is characterized by being in a state of not using the fire water for a long time. In fire-fighting systems, the use of fire-fighting water is longer than in the case of use of fire-fighting water (ie in the event of a fire), but even when no fire-fighting water is used, the set pressure required by the installation must always be maintained.

However, due to the following reasons, the secondary pressure of the pressure reducing valve is excessively higher than the set pressure may cause a lot of problems in the fire fighting equipment.

1) Change in the pressure of fire water inlet (primary side)

2) Pressure change by changing water temperature and dissolved oxygen in the pipe

3) Pressure rise due to leakage of pressure reducing valve

4) Pressure rise that may occur before and after the pressure reducing valve

The main reason that the secondary pressure of the pressure reducing valve becomes higher than the set pressure when the fire water is not used is because of the reason of the above 3), that is, very small leakage of water continuously occurs on the secondary side of the pressure reducing valve. This is a structural problem in which leakage from the pilot valve is essential. As a result, the pressure reducing valve primary side and the secondary side pressure eventually change to the same pressure state, that is, the equal pressure state. For this reason, the problem that a secondary pipe may not be able to withstand pressure and it may burst may arise, and the complaints of fire-fighting officials are prevalent. In order to solve this problem, there are many cases where a zone is divided by a pump without applying a pressure reducing valve to a lower part or a higher part, or a method of applying pressure piping instead of general piping material to the secondary piping of the pressure reducing valve. This is more expensive than necessary.

Therefore, there is an urgent need for a new pressure reducing valve that eliminates unnecessary costs in the piping of fire-fighting equipment by maintaining water pressure at the primary and secondary sides of the pressure reducing valve even when the fluid flow is stagnant. .

The present invention has been made to solve the above problems of the conventional fire-reducing pressure reducing valve, in particular, when there is stagnant high-pressure water without a flow of fluid in the pipe and decompression is necessary, the first side of the pressure reducing valve, that is, the secondary side from the high pressure side. That is, when the water flow is acknowledged due to leakage to the low pressure side, and the low pressure side becomes a pressure slightly higher than the set pressure due to such leakage, the fluid leaked by a separate relief pilot valve is flowed and drained, so that It is an object of the present invention to provide a new fire fighting pressure reducing valve which can always maintain the effect of the intended pressure reduction.

It is an object of the present invention to provide a new fire fighting pressure reducing valve that enables the pressure reducing function of the pressure reducing valve to maintain a stable secondary pressure at any pressure change without greatly changing the structure of the conventional pressure reducing valve.

In addition, the present invention is to ensure that the secondary pressure is always maintained even in the high pressure water pipe with the pressure reducing valve stagnant, thereby eliminating the phenomenon of the pressure equalization valve 1/2 side of the stagnant water, and consequently the secondary pipe material It is possible to use general piping materials instead of pressure piping materials, and the system can be composed of a single pressure reducing valve without the need to apply high- and low-zone zone separation pumps, thereby reducing the total cost of fire-fighting equipment, and It is an object of the present invention to provide a new fire fighting pressure reducing valve having advantages such as better construction.

This object is achieved by a fire fighting pressure reducing valve provided according to the present invention.

Pressure reducing valve provided according to the present invention, as a pressure reducing valve for fire fighting; Diaphragm for adjusting the position of the primary inflow chamber into which the water of the supply pressure flows in, the secondary outflow chamber in which the high pressure water is reduced under pressure, and the diaphragm for determining the size of the opening degree to which the primary side and the secondary side are connected. A main valve comprising a chamber; An ejector for connecting the inflow chamber and the diaphragm chamber outside the main valve; A pilot valve connecting the outlet chamber and the diaphragm chamber to the outside of the main valve via the ejector; And a relief pilot valve connecting between the outlet chamber and the outlet, wherein when the pressure of the outlet chamber is lower than the first predetermined pressure lower than the supply pressure, the ejector and the pilot valve are connected to the outlet valve. Operate a small amount of water from a diaphragm chamber into the outflow chamber to open the main valve further; When the pressure of the outlet chamber is higher than the predetermined first set pressure but lower than the predetermined second set pressure lower than the supply pressure, the ejector and the pilot valve allow a small amount of water to flow into the diaphragm chamber. The main valve is further closed; When the pressure of the outlet chamber is higher than the second preset pressure, the relief pilot valve causes a small amount of water to be discharged from the outlet chamber so that the pressure of the outlet chamber is below the second preset pressure. Works to fall.

In a preferred embodiment, the preset second set pressure is 0.2 to 0.5 kg / cm2 higher than the preset first set pressure.

Hereinafter, with reference to the accompanying drawings a specific embodiment of the present invention will be described in detail.

Figure 2 is a schematic piping diagram showing the structure of a pressure reducing valve for fire according to an embodiment of the present invention. As shown, the fire-reducing pressure reducing valve 10 according to an embodiment of the present invention, including the main valve 12, pilot valve 14, ejector 16 and relief pilot valve 20 do.

The main valve 12 is a valve installed in the main pipe to reduce the high pressure water, that is, the fire water supplied to the low pressure fire water. Specifically, the main valve 12 has a primary inlet chamber 122 through which water at a supply pressure flows in, a secondary side outflow chamber 124 through which the high pressure water is decompressed, and an opening degree at which the primary side and the secondary side are connected. And a diaphragm chamber 126 for adjusting the position of the diaphragm for determining the size. The pressure reducing function of the main valve 12 may be determined by the size of the opening degree, and the size of the opening degree may be adjusted by the pressure of the water filled in the diaphragm chamber 126.

The ejector 16 connects between the inlet chamber 122 and the diaphragm chamber 126 outside the main valve 12, preferably via a strainer 18. The strainer 18 is a means for preventing foreign substances from flowing into the pipe connected to the ejector 16 having a relatively small diameter and the diaphragm chamber 126 from the inlet chamber 122. The ejector 16 senses the pressure in the diaphragm chamber 126 and adjusts the flow of water between the inlet chamber 122 and the diaphragm chamber 126 to provide a depressurization control effect as described below. to be.

The pilot valve 14 is a small diameter pilot valve that connects the outlet chamber 124 and the diaphragm chamber 126 to the outside of the main valve 12 via the ejector 16. The pilot valve 14 serves to adjust the opening degree of the main valve 12 by sensing the pressure of the outflow chamber 124 to regulate the flow of water between the diaphragm chamber 126 and the outflow chamber 124. Means.

However, the pilot valve 14 has a low pressure from the high pressure inlet chamber 122 even when fire water is not used, that is, even when the high pressure water is stagnated in the inlet chamber 122 and the main valve 12 is closed. To leak into the outflow chamber 124 so that the pressure in the outflow chamber 124 becomes equal to the pressure in the inflow chamber 122. Therefore, in order to solve the leakage problem of the pilot valve 14, in accordance with the present invention, includes a relief pilot valve 20 for connecting between the outlet chamber 124 and the outlet 30. The relief pilot valve 20 is a small-diameter relief valve that senses the pressure in the outlet chamber 124 to drain a small amount of water from the outlet chamber 124 when the pressure is greater than a predetermined pressure, and consequently, It is responsible for lowering the pressure below a certain pressure. Accordingly, the relief pilot valve 20 can solve the leakage problem of the pilot valve 14.

In the operation of the pressure reducing valve 10, when the pressure of the outlet chamber 124 is lower than the first predetermined pressure lower than the supply pressure, the ejector 16 and the pilot valve 14 is A small amount of water flows out of the diaphragm chamber 126 into the outflow chamber 124 so that the main valve 12 is further opened. In addition, when the pressure of the outlet chamber 124 is higher than the predetermined first set pressure but lower than the predetermined second set pressure lower than the supply pressure, the ejector 16 and the pilot valve 14 A small amount of water flows into the diaphragm chamber 126 so that the main valve 12 is further closed. Furthermore, when the pressure of the outflow chamber 124 is higher than the preset second set pressure, the relief pilot valve 20 causes a small amount of water to be discharged from the outflow chamber 124, so that the outflow chamber The pressure of 124 is operated to fall below the second preset pressure.

Here, the preset second set pressure is preferably 0.2 ~ 0.5 kg / cm2 higher than the preset first set pressure. In this case, the preset first predetermined pressure may be, for example, 12 kg / cm 2 (spring cooler) and 7 kg / cm 2 (before indoor fire extinguishing).

In the above, the present invention has been described with reference to specific examples of fire-reducing valves, but the scope of the present invention is not limited to the described examples, and those skilled in the art based on the disclosed contents Various modifications and variations are possible by applying the common knowledge of the relevant technical field. Therefore, it is pointed out that the scope of the present invention should be interpreted not by the examples described, but by the appended claims.

As described above, according to the present invention, the movement of water due to leakage from the primary side, ie the high pressure side, to the secondary side or the low pressure side of the pressure reducing valve, especially when stagnant high pressure water without fluid flow is in the pipe and pressure reduction is required. If the low pressure side becomes a pressure slightly higher than the set pressure due to this leakage, the fluid leaked by the separate relief pilot valve can be flowed and drained to maintain the effect of the first intended pressure reduction on the main pipe at all times. To provide the effect.

The present invention provides an effect that the pressure reducing function of the pressure reducing valve can maintain a stable secondary pressure at any pressure change without greatly changing the structure of the conventional pressure reducing valve.

In addition, the present invention is to ensure that the secondary pressure is always maintained even in the high pressure water pipe with the pressure reducing valve stagnant, thereby eliminating the phenomenon of the pressure equalization valve 1/2 side of the stagnant water, and consequently the secondary pipe material It is possible to use general piping materials instead of pressure piping materials, and the system can be composed of a single pressure reducing valve without the need to apply high- and low-zone zone separation pumps, thereby reducing the total cost of fire-fighting equipment, and It has a remarkable effect, such as making workability more favorable.

Claims (2)

As a pressure reducing valve 10 for fire fighting; Position of the primary inflow chamber 122 into which the water of the supply pressure flows in, the secondary outflow chamber 124 in which the high pressure water is decompressed, and the diaphragm determining the size of the opening degree to which the primary side and the secondary side are connected. A main valve 12 including a diaphragm chamber 126 for adjusting the pressure; An ejector (16) connecting the inlet chamber (122) and the diaphragm chamber (126) to the outside of the main valve (12); A pilot valve (14) connecting between the outlet chamber (124) and the diaphragm chamber (126) outside the main valve (12) via the ejector (16); And A relief pilot valve (20) connecting between the outlet chamber (124) and the outlet (30), wherein When the pressure of the outlet chamber 124 is lower than the predetermined first set pressure lower than the supply pressure, the ejector 16 and the pilot valve 14 are separated from the diaphragm chamber 126 by a small amount of water. Cause the main valve (12) to open further by allowing it to flow out of the outlet chamber (124); When the pressure of the outlet chamber 124 is higher than the predetermined first set pressure but lower than the predetermined second set pressure lower than the supply pressure, the ejector 16 and the pilot valve 14 are connected to the dia. A small amount of water flows into the flam chamber 126 so as to close the main valve 12 further; When the pressure of the outlet chamber 124 is higher than the second preset pressure, the relief pilot valve 20 causes a small amount of water to be discharged from the outlet chamber 124, thereby allowing the outlet chamber 124 to be discharged. To operate so that the pressure of the drop below the preset second set pressure Relief valve for fire, characterized in that. The pressure reducing valve for fire fighting according to claim 1, wherein the second preset pressure is 0.2 to 0.5 kg / cm2 higher than the first preset pressure.

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