JP3013106B2 - Sprinkler fire extinguishing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprinkler fire extinguishing system.

[0002]

2. Description of the Related Art Sprinkler fire extinguishing systems have conventionally used various systems such as open and closed wet and dry systems. Conventionally, in the closed type sprinkler fire extinguishing equipment, the fire extinguishing fluid pressurized up to the end of the closed type sprinkler head provided in each warning area is always filled, and water spraying operation can be taken simultaneously with fire detection, This is the most common equipment used for buildings and the like. In a closed type sprinkler fire extinguishing system, a large amount of fire extinguishing liquid is released due to damage to the sprinkler head, etc., so a fire detector is installed in addition to the sprinkler head, and the fire extinguishing liquid is sent to the sprinkler head by operation of the fire detector due to fire. A pre-actuated type that fills and waters when the sprinkler head operates
(Pre-action type) There is a sprinkler fire extinguishing system. In this pre-operation type, the air is slightly pressurized in the pipe to the sprinkler head, and the fire extinguishing liquid is not released when the sprinkler head is damaged or malfunctions. Therefore, it is installed in a place where water damage such as a part is extremely disliked.

[0003]

In the closed-type sprinkler fire extinguishing system, the fire extinguishing solution pressurized up to the end of the pipe is always filled, so that the fire extinguishing solution can be discharged simultaneously with the operation of the sprinkler head by detecting the fire. There is a feature that there is. However, if the sprinkler head is opened due to an accident such as being hit by an object, the pressurized fire extinguishing liquid is released, and the pressurized liquid sending device is started. There is a problem that watering is continued until it stops, resulting in a serious water damage accident.

On the other hand, a pre-actuated sprinkler fire extinguishing system
When the fire detector detects a fire and the closed type sprinkler head operates, that is, the fire extinguishing liquid is released only by the AND condition between the fire detector and the sprinkler head. Since it is only filled with pressurized air, it has the characteristic that even if the closed sprinkler head is opened due to impact or the like, a water damage accident does not occur. However, a compressor or the like is required to pressurize the secondary pipe to which the closed sprinkler head is connected, and the entire equipment becomes complicated and expensive. Since the discharged air comes out, there is a problem that a delay occurs before the fire extinguishing liquid starts to be discharged normally.

A particularly important problem is that at the time of fire extinguishing, a high hydraulic pressure equivalent to the primary side of the release valve is applied to the secondary side pipe provided with the sprinkler head. It is necessary to use equipment members having the same pressure resistance grade as the primary side. (a) This is one of the factors that hinder the spread of sprinkler fire extinguishing equipment due to the high cost of secondary piping and valves. (b) At the moment when the fire phenomenon is detected and the opening valve is opened, the high primary side hydraulic pressure is applied to the secondary side at a time, and as shown by the dotted line in FIG. 3 by the action of the water hammer. In addition, the hydraulic pressure on the secondary side abnormally increases, which is a serious problem with regard to the pressure resistance grade of the above-mentioned equipment members.

The present invention has been proposed to solve such various problems of the conventional sprinkler fire extinguishing system, and suppresses an abnormal increase in the pressure of a fire extinguishing liquid when an opening valve is opened or during a fire extinguishing operation. The pressure resistance grade of the secondary side equipment members may be low, the fire extinguishing liquid can be released together with the operation of the sprinkler head, and even if the closed type sprinkler head is opened due to impact or the like, water damage accidents can be suppressed, Moreover,
The equipment configuration provides a simple and inexpensive sprinkler fire extinguishing equipment.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a closed sprinkler head 4 and a primary side 8 and a secondary side 7 which are always closed in a guard area to detect a fire phenomenon. An opening valve 6 that is opened by a signal based on the fire detection means 1 that is provided, the primary pipe of the opening valve 6 is connected to the fire extinguishing liquid supply means 13, the secondary pipe is connected to the closed sprinkler head 4, In the sprinkler fire extinguishing equipment respectively connected, the opening valve 6 has a pressure regulating device R for adjusting the pressure of the fire extinguishing liquid on the primary side 8 to a predetermined pressure and supplying it to the secondary side 7 when in the open state. And a pressure reducing device A which is opened during the opening of the opening valve 6 and discharges the fire extinguishing liquid in the secondary pipe.

The opening valve 6 and the pressure reducing device A are opened by an electric signal based on the fire detecting means 1, and the pressure reducing device A is configured to close at a predetermined time after opening.

The pressure reducing device A is configured to close when the hydraulic pressure in the secondary pipe 5 reaches a second predetermined pressure set lower than the predetermined pressure by the release valve 6.

The pressure reducing device A is configured to be controlled to open and close by a pressure switch 34 for sending a signal when the secondary pipe 5 exceeds a predetermined pressure.

When the opening valve 6 is closed, the secondary side pipe 5 can be filled with a non-pressurized or slightly pressurized fire extinguishing liquid.

[0012]

The fire extinguishing liquid, which has been depressurized and adjusted to a predetermined pressure by the pressure regulator R, is supplied to the secondary pipe 5 while the opening valve 6 is open, so that equipment such as the secondary pipe 7 and the sprinkler head 4 are provided. A member having a sufficiently low pressure resistance grade can be used, and the pressure reducing device A that opens during the opening of the opening valve 6 is capable of releasing a transient abnormal pressure rising pressure fluid that is instantaneously generated when the opening valve 6 is opened. Since this is discharged directly, this abnormal pressure increase
As a result, abnormal pressure is not applied to the device members such as the secondary pipe 5 and the sprinkler head 4.

The opening and closing operations of the opening valve 6 and the pressure reducing device A are controlled by a simple circuit configuration based on an electric signal based on the fire detecting means 1.

If the pressure reducing device A is configured to be closed when the hydraulic pressure of the secondary pipe 5 reaches a second predetermined pressure set lower than the predetermined pressure by the opening valve 6,
Even when the abnormal pressure increase of the hydraulic pressure when the opening valve 6 is opened is prolonged, the pressure increase can be reliably reduced.

Since the pressure reducing device A is configured so as to be controlled to be opened and closed by the pressure switch 34 for sending a signal when the secondary side pipe 5 exceeds a predetermined pressure, the transient generated during the fire extinguishing operation. Temporary abnormal pressure increase of the hydraulic pressure is also mitigated by the pressure increase mitigation device A that is opened by the abnormal pressure increase, so that the withstand pressure grade of the equipment such as the secondary pipe 5 and the sprinkler head 4 can be reduced with confidence. it can.

If the non-pressurized or slightly pressurized fire extinguishing liquid is filled in the secondary pipe 5 when the opening valve 6 is closed (at the time of fire monitoring), the sprinkler can be reduced in comparison with the conventional pre-actuated sprinkler fire extinguishing equipment. The fire extinguishing liquid is discharged simultaneously with the opening operation of the head 4 and there is no delay in the fire extinguishing operation, so that a compressor for constantly pressurizing the inside of the secondary pipe with air is unnecessary, and unlike a closed type sprinkler fire extinguishing system. No major water damage accidents occur due to malfunction of the sprinkler head.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of a sprinkler fire extinguishing system. A fire detector 1 of a differential type, a constant temperature type, or the like provided in a guard area is connected to a receiver 3 via an electric line 2. The closed type sprinkler head 4 provided on the ceiling of the security area as well as the fire detector 1 is connected to the secondary side 7 of the opening valve 6 via the secondary side pipe 5. The primary side 8 of the opening valve 6 is connected to a pressurized liquid sending device 13 as fire extinguishing liquid supply means, and is connected to the receiving board 3 by a gate valve 9, a pump 10, and an electric circuit 11 shown in FIG. Motor
In addition to 12 and the like, the pressurized liquid sending device 13 is provided with a pressurizing means such as a normal check valve and a pressurized air tank (not shown).

The opening valve 6 is provided with a pressure regulator R for adjusting the hydraulic pressure of the primary side 8 to a predetermined pressure and supplying the same to the secondary side 7. That is, the primary side 8 and the secondary side 7 of the opening valve 6 are separated by a valve seat 14 and a valve body 15 which opens and closes the valve seat 14, and a valve seat wall 20 in a valve box 16 and this valve body An operation chamber 17 is formed by the valve body 15, and a small hole 19 for introducing a part of the hydraulic pressure on the primary side 8 is opened in the valve body 15 urged to close the valve seat 14 by a spring 18. . An operation secondary chamber 17a is formed by the valve seat wall 20 and the partition 21 in the valve box 16, and the operation secondary chamber 17a is electrically connected to the receiver 3 via an electric circuit 23, such as a motor or a solenoid. The operation valve 25 is opened and closed by the section 24. Operation room 17
Is provided with a valve body opening adjustment hole 26 which communicates with the operation secondary chamber 17a, and a secondary pressure monitoring chamber 30 is provided in the valve box 16 by a flam 29 attached to the other end of the needle 27.
Is formed, and the secondary pressure monitoring chamber 30 is connected to the secondary side 7 of the opening valve 6 by the pipe 31. The flam 29 is urged by a secondary pressure setting spring 28 so as to increase the opening of the valve body opening adjustment hole 26, and the valve body is opened by the displacement of a needle 27 integrated with the flam 29. The opening of the degree adjustment hole 26 is adjusted, and the hydraulic pressure on the primary side 8 is reduced to a predetermined pressure and supplied to the secondary side 7.

The pipe 32 connected to the secondary side 7 is provided with a pressure switch 34 for detecting the opening of the opening valve 6 and notifying the receiving board 3 of the opening via an electric circuit 33, and a drain pipe 36 through a gate valve 35. The pipe 32 is connected to the secondary side of the operation valve 25. The rising pipe 37 near the end of the secondary pipe 5 of the sprinkler head 4 is provided with a drain valve 49 as an embodiment of the pressure reducing device A, which is a main configuration of the present invention, from the position where the sprinkler head 4 and the like are arranged. Also connected to a higher position,
The secondary side 50 of the drain valve 49 is connected to the drain pipe 40, and the drain valve 49 operates the fire detector 1 so that the secondary pipe 5 has a predetermined diameter and a predetermined diameter during a predetermined state. 40, and are configured to be opened for a predetermined time by the operation of a pressure switch 34 as an example of a detector that detects a predetermined hydraulic pressure in the secondary pipe 5. is there.

The drain valve 49 has a primary side 52 having a valve seat 51 opening to the riser pipe 37, a small-diameter port 53 and a large-diameter port 54, as exemplified in a vertical plan view in FIG. A ball valve element 55 that can rotate about the spherical center C;
A ball valve comprising a secondary side 50 having a valve seat 56 opening to the drain pipe 40, and the ball valve 55 is rotated by 90 degrees to the receiving board 3 through an electric path 57 so as to rotate by 90 degrees. It is constituted by a motor or a motor-driven unit 58 such as a solenoid. The motor-operated portion 58 of the drain valve 49 is configured such that the small-diameter port 53 is connected to the primary side 52 and the secondary side 50 when the fire detector 1 is not operated and when a predetermined time has elapsed after the release valve 6 is opened. Is controlled by the receiving board 3 so as to be in the desired position.
Although not shown, the small-diameter port 53 of the drain valve 49 facilitates the operation for filling the secondary pipe 5 with a non-pressurized fire extinguishing liquid during fire monitoring, as described later. If a motor-operated valve that opens and closes is used, the secondary pipe 5 can be pressurized with a small pressure fire extinguishing liquid. In this case, the riser pipe 37 becomes unnecessary. The hydraulic pressure of the primary side 8 of the opening valve 6 is detected by a pressure gauge 46, and the hydraulic pressure of the secondary pipe 5 is detected by a pressure gauge 47.

Next, the operation of the above embodiment will be described.
First, a non-pressurized fire extinguishing liquid is filled in the secondary side 7 of the opening valve 6, such as the secondary pipe 5, the riser pipe 37, and the like. First, fill
It is assumed that the operation chamber 17 is pressurized through the primary side 8 of the open valve 6 by the pressurized liquid sending device 13. Next, the gate valve 9 is closed, the operation valve 25 is opened, and the pressure in the operation chamber 17 is reduced, so that the release valve 6 is opened. Then, the gate valve 9 is gradually opened, and the fire extinguishing liquid is allowed to flow slowly into the secondary piping system of the opening valve 6. The fire extinguishing liquid flows from the secondary side 7 of the release valve 6 to the secondary side pipe 5, the sprinkler head 4, and the riser pipe 37, and slightly flows down the drain pipe 40 beyond the small diameter port 53 of the drain valve 49. When the fire extinguishing liquid has passed over the small-diameter port 53, the operation valve 25 is closed, and the release valve 6 is closed.
As a result, the pressure liquid that has acted on the secondary-side piping system is discharged to the drain pipe 40 and is charged without pressure. In this manner, the secondary pipe 5, the sprinkler head 4 and the like are filled with liquid, and the rate of air communication by the small-diameter port 53 of the drain valve 49 connected to the riser pipe 37 is kept small, so that the fire extinguishing liquid Can be suppressed to the atmosphere, and the pressureless liquid state can be maintained for a long time. In a normal state in which the fire detector 1 is not operated, the fire extinguishing liquid on the primary side 8 enters the operation room 17 through the small hole 19 of the opening valve 6, and the valve body 15 is moved to the valve seat 14 by the hydraulic pressure in the operation room 17 and the spring 18. Is closed, and the valve body 15 is monitored by the pressure switch 34.

In this state, when a fire occurs and the fire detector 1 operates, a fire signal is transmitted to the receiver 3. In the receiving panel 3, the electric signal 58 of the drain valve 49 is generated by the fire signal.
And the ball valve body 55 rotates 90 degrees to rotate the large-diameter port.
The opening valve 6 is located on the primary side 52 and the secondary side 50.
The end of the secondary side 7 is fully opened to the atmosphere by the large-diameter port 54. Also, in the receiving panel 3, since the electric valve 24 is operated and the operation valve 25 is opened at the same time or slightly after the fire signal, the hydraulic pressure in the operation chamber 17 of the opening valve 6 is supplied from the drain pipe 36 through the operation secondary chamber 17a. After being discharged, the hydraulic pressure is reduced, and the hydraulic pressure difference between the primary side 8 and the operation chamber 17 causes the release valve 6 to open.
Is opened. On the other hand, the pressure liquid on the primary side 8 is passed through the secondary side 7 by a pressurizing means such as a pressure air tank (not shown), and the secondary side pipe 5
And the pressure switch 34 operates to notify the receiving board 3 of the opening of the opening valve 6. The abnormally high pressure fluid that is instantaneously generated when the opening valve 6 is opened is immediately discharged from the small diameter port 53 of the drain valve 49 to the drain pipe 40, and the abnormal pressure is increased to a predetermined pressure P as shown by a solid line in FIG. The pressure was relaxed to a slightly larger size, and no abnormal pressure was applied to the equipment members such as the secondary pipe 5 and the sprinkler head 4. When a predetermined time elapses after the liquid feeding device 13 is started and the hydraulic pressure on the secondary side 7 returns to the predetermined pressure P, the electric unit is controlled by a command from timer means (not shown) provided in the receiving panel 3 or the like. 58 operates to rotate the ball valve body 55 to a position where the small-diameter port 53 looks into the secondary side pipe 37, and wasteful drainage from the drainage valve 49 becomes small.

When the hydraulic pressure on the secondary side 7 exceeds the set pressure of the pressure regulator R, the flam 29 and the needle 27 are pushed to the left, the valve body opening adjusting hole 26 is closed, and the operation chamber 17 is closed. The drainage stops and the valve body 15 closes the valve seat 14 by the spring 18. When the hydraulic pressure on the secondary side 7 falls below the set pressure of the pressure regulator R, the needle 27 is returned by the secondary pressure setting spring 28, the valve body opening adjustment hole 26 is opened, and the operation chamber 17 is operated in the secondary operation. The liquid is drained through the chamber 17a, and the valve body 15 returns due to the hydraulic pressure on the secondary side 7, and the valve seat 1
4 is opened and the fire extinguishing liquid on the primary side 8 is introduced into the secondary side 7 and the hydraulic pressure on the secondary side 7 is restored, and thus the hydraulic pressure on the secondary side 7 is reduced to the level of the fire extinguishing liquid on the primary side 8. The pressure is reduced to a predetermined pressure required for fire fighting.

When the temperature at the fire point further rises, the sprinkler head 4 is opened and the fire extinguishing liquid in the secondary pipe 5 is discharged, and the hydraulic pressure on the secondary side 7 drops rapidly. Based on the decreasing rate of the pressurized water from the pressurizing means such as the pressurized air tank, it is determined in the receiving panel 3 whether the pressure is reduced from the small diameter port 53 of the drain valve 49 or the sprinkler head 4. When the pressure is reduced from the sprinkler head 4, the pump 10 of the pressurized liquid sending device 13 is started. The activation of the pump 10 of the pressurized liquid sending device 13 is as follows.
It may be performed by detecting a continuous pressurizing time of the pressurizing unit.

Although not shown, the boosting mitigation device A
Is closed when the hydraulic pressure of the secondary side pipe 5 reaches a second predetermined pressure set lower than the predetermined pressure by the opening valve 6, so that when the opening valve 6 is opened, Even when the abnormal pressure increase of the hydraulic pressure is prolonged, the pressure increase can be reliably alleviated. Alternatively, if the pressure reducing device A is configured to be opened and closed by a pressure switch 34 that sends a signal when the secondary pipe 5 exceeds a predetermined pressure, the opening valve 6 can be opened (fire monitoring). Not only), but also the transient and temporary abnormal pressure increase of the hydraulic pressure occurring during the fire extinguishing operation is mitigated by the pressure increase mitigation device A that performs the opening operation due to the abnormal pressure increase.
The pressure resistance grade of equipment members such as the secondary pipe 5 and the sprinkler head 4 can be reduced with ease.

The following effects can be obtained by the above embodiment. (a) In the sprinkler head 4 and the secondary pipe 5,
Since there is no air as in the conventional pre-actuated sprinkler fire extinguishing system, the fire extinguishing liquid is discharged simultaneously with the opening operation of the sprinkler head 4, and there is no delay in the fire extinguishing operation. (b) A compressor for constantly pressurizing the piping with air is not required in this configuration, and the equipment cost is reduced. (c) The hydraulic pressure on the primary side 8 is reduced and adjusted to a predetermined pressure by the pressure regulator R and supplied to the secondary side pipe 5 and the like, so that the secondary side pipe 5, the sprinkler head 4, valves and the like, It is sufficient that the pressure resistance grade of the equipment member on the side is sufficiently low, the cost of the piping material is low, and the piping work is simple. (d) Transient abnormal pressure rise of the hydraulic pressure which occurs when the release valve 6 is opened and abnormal pressure rise during opening of the sprinkler head 4 are alleviated by the drain valve 49, and the secondary side piping, the sprinkler head 4, etc. The function of lowering the pressure-resistant grade can always be ensured even during the above-mentioned transition or unexpected abnormal pressure rise. You can lower it with confidence. (e) Since the non-pressurized fire extinguishing liquid is filled in the secondary pipe 5, when the sprinkler head 4 is abnormally opened, the secondary pipe 5
Only a small amount of fire extinguishing liquid in the branch pipe from
Damage caused by flood damage is small. The effects of (a) to (e) are as follows: (a)
Other effects can be obtained. Further, a small diameter port of the drain valve 49 is provided.
Even when the fire extinguishing liquid is slightly pressurized by eliminating the fire 53 (a)
The effects (1) to (e) are obtained, and a pressurizing means such as a bypass pipe is required. However, it is possible to detect a defect in the secondary pipe 5 and a malfunction of the sprinkler head 4.

In the illustrated example, the pressure regulating device R is provided in the opening valve 6 and the valve element 15 of the pressurized liquid sending device 13 is used for the pressure regulating operation, but the pressure regulating device R is provided separately from the opening valve 6. Further, in the above-described embodiment, the valve body 15 is opened by reducing the pressure in the operation chamber 17, but the valve body may be opened by increasing the pressure in the operation chamber. Of course. Also, in the structure of the embodiment, for fire monitoring,
Instead of charging the non-pressurized fire extinguishing liquid to the secondary side pipe 5, the riser pipe 37, and the primary side 52 of the drain valve 49, the drain valve 49 is used.
The small-diameter port 53 can be used in a deformed manner in which a small pressure extinguishing liquid is filled with the port closed, and a simple configuration is provided by providing a secondary pressure regulating valve, an orifice, etc. in a pipe bypassing the opening valve 6. it can. In this case, too, the secondary side is depressurized and adjusted by the pressure regulating device R of the opening valve 6, and the transient abnormal pressure increase of the hydraulic pressure that occurs when the opening valve 6 is opened is reduced by the small diameter port of the drain valve 49.
The pressure relief grade of the secondary pipe 5, the sprinkler head 4 and the like can be reduced, and the fire extinguishing equipment can be manufactured at low cost. In this case, it is desirable to provide another pressure releasing means. In this configuration, the opening of the release valve 6 is not limited to the one based on the signal of the fire detector 1, but may be based on a pressure change due to the opening of the sprinkler head in the secondary pipe 5 with a small pressure. Further, a contact for detecting the opening operation of the sprinkler head 4 may be provided, including a case where no pressure is applied.

[0028]

As described above, according to the present invention, while the opening valve 6 is open, the fire extinguishing liquid reduced to a predetermined pressure by the pressure regulator R is supplied to the secondary pipe 5, so that the secondary Side 7
Subsequent piping and sprinkler heads 4 and other equipment members are sprinkler fire extinguishing equipment that can use those having a sufficiently low pressure resistance grade. Since the pressure fluid of the transient abnormal pressure rise that is instantaneously generated when the valve 6 is opened is immediately discharged, the abnormal pressure rise is surely alleviated by the pressure increase mitigation device A, and abnormalities occur in the equipment such as the secondary pipe 5 and the sprinkler head 4. Pressure rise is no longer applied, the pressure resistance grade of the equipment members can be reduced, and the sprinkler fire extinguishing equipment can be implemented at low cost and easily implemented.

The opening and closing operations of the opening valve 6 and the pressure reducing device A are controlled by a simple circuit configuration based on an electric signal based on the fire detecting means 1.

The pressure reducing device A is configured to be closed when the hydraulic pressure of the secondary pipe 5 reaches a second predetermined pressure set lower than the predetermined pressure by the opening valve 6. In addition, even when the abnormal pressure increase of the hydraulic pressure when the opening valve 6 is opened is prolonged, the pressure increase can be reliably reduced.

Since the pressure reducing device A is configured to be controlled to be opened and closed by the pressure switch 34 for sending a signal when the secondary pipe 5 exceeds a predetermined pressure, the transient generated during the fire extinguishing operation. The pressure relief device A, which operates to release the temporary abnormal pressure rise due to the signal from the pressure switch 34.
Thus, the pressure-resistant grade of equipment members such as the secondary pipe 5 and the sprinkler head 4 can be reduced with ease.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a drain valve used in FIG.

FIG. 3 is a graph showing a boost relaxation characteristic according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fire detector (fire detection means) 4 Sprinkler head 6 Opening valve 7 Secondary side 8 Primary side 13 Pressurized liquid sending device (fire extinguishing liquid supply means) 34 Pressure switch A Pressure rise mitigation device R Pressure regulator

Claims (5)

(57) [Claims] In a security area, a closed type sprinkler head and an opening valve which is always closed with a primary side and a secondary side and is opened by a signal based on a fire detecting means for detecting a fire phenomenon are provided. In the sprinkler fire extinguisher provided, the primary pipe of the open valve is connected to the fire extinguishing liquid supply means, the secondary pipe is connected to the closed type sprinkler head, and when the open valve is in the open state, the primary fire extinguishing is performed. A pressure regulator for reducing the pressure of the liquid to a predetermined pressure and supplying it to the secondary side, and which is opened during the initial stage of opening of the release valve and discharges the fire extinguishing liquid in the secondary side pipe; Sprinkler fire extinguishing equipment characterized by comprising: 2. The sprinkler according to claim 1, wherein the opening valve and the pressure reducing device are opened by an electric signal based on the fire detecting means, and the pressure reducing device is closed at a predetermined time after the opening. Fire extinguishing equipment. 3. The pressure reducing device according to claim 2, wherein the hydraulic pressure of the secondary side pipe is set lower than the predetermined pressure by an opening valve.
2. The sprinkler fire extinguishing system according to claim 1, wherein the sprinkler is closed when a predetermined pressure is reached. 4. The pressure reducing device according to claim 1, wherein the pressure is reduced by a pressure switch that sends a signal when the pressure of the secondary pipe exceeds a predetermined pressure.
Two or three sprinkler fire extinguishing systems. 5. The sprinkler fire extinguishing system according to claim 1, wherein the non-pressurized or slightly pressurized fire extinguishing liquid can be charged into the secondary pipe when the opening valve is closed. .