JPH09218717A - Monitor-type pressure regulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the change of gas supply pressure in switching backup. SOLUTION: A monitor pressure regulator 34 and a worker pressure regulator 30 are connected between a primary-side conduit 21 and a secondary-side conduit 22 in series. The worker pressure regulator 30 and the monitor pressure regulator 34 are unloading-types and pressure which is set by pilot valves 33 and 37 is almost equal. In pilot conduits 31 and 35, a shut-off valve 38 is normally opened and a shut-off valve 39 is closed, the worker pressure regulator 30 executes a pressure regulating operation and the monitor pressure regulator 34 is opened. When the gas supply pressure of the secondary-side conduit 22 reaches switch pressure by exceeding setting pressure, the shut-off valve 38 is closed, the shut-off valve 39 is opened, the pressure regulating operation by the monitor pressure regulator 34 is started and the worker pressure regulator 30 becomes an open state. The setting pressure of the worker pressure regulator 30 is almost equal to that of the monitor pressure regulator 34, the change in the supply pressure to the secondary-side conduit 22 is small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitor type pressure regulator having a backup function provided in a gas supply line for city gas or the like, and more particularly to a monitor type pressure regulator capable of suppressing fluctuations in gas supply pressure during backup.

[0002]

2. Description of the Related Art Conventionally, in a facility for supplying city gas or the like, the pressure of gas is sequentially reduced from high pressure to near atmospheric pressure and supplied. In the process of pressure reduction, a pressure regulator called a governor is used. In order to stably supply gas, a system is adopted in which a pressure regulator is considered and a plurality of pressure regulators are used to switch to a backup system in the event of a failure.

FIG. 5 shows a two-series, two-shutoff system, in which the city gas supplied from the primary side pipeline 1 is depressurized and stably supplied to the secondary side pipeline 2, so that the governor 4 of the main system 3 and the shutoff are cut off. Governor 7 of valve 5 and sub-system 6 in parallel with main system 3
And a shutoff valve 8 is provided. The supply pressure to the secondary side pipeline 2 by the sub system 6 is set lower than the supply pressure to the secondary side pipeline 2 by the main system 3. Normally, the main system 3 operates, the governor 4 of the main system 3 fails, the pressure in the secondary side pipe line 2 rises above the set pressure of the main system 3, and the set pressure for switching to the sub system 6 is reached. When you reach
The shutoff valve 5 of the main system 3 is closed and the governor 7 of the sub system 6 is closed.
Works.

In the monitor type configuration shown in FIG. 6, the worker pressure regulator 10 normally performs a pressure regulating operation. Pilot line 1
The restrictor 12 which is a throttle provided in 1 and the driving pressure supplied from the connection part of the pilot valve 13 for setting the operating pressure of the worker pressure regulator 10 and the pressure of the primary side pipe line 1 Controlled. A monitor pressure regulator 14 is provided on the upstream side of the worker pressure regulator 10, and is provided between the primary side pipeline 1 and the secondary side pipeline 2 of the pilot pipeline 15. A restrictor 16 and a pilot valve 17 are provided in the pilot line 15 of the monitor pressure regulator 14 and operate by the differential pressure between the intermediate pressure between them and the pressure of the primary side line 1. The drive pressure of the pilot valve 17 of the monitor pressure regulator 14 is set higher than the drive pressure of the pilot valve 13 of the worker pressure regulator 10. Each pilot valve 1 until the driving pressure is reached
3, 17 are in an open state. Therefore, the worker pressure regulator 1
As long as 0 is operating normally, the monitor pressure regulator 14 always operates at a secondary pressure lower than the set drive pressure, and the valve is always opened to try to increase the secondary pressure by opening the valve. Becomes As the worker pressure regulator 10 and the monitor pressure regulator 14, for example, TYPE 399 governor manufactured by Fisher Controls is used.

If the worker pressure regulator 10 fails, for example, the valve body is damaged and rises above the supply pressure of the secondary side pipe line 2, the set pressure of the monitor pressure regulator 14 is reached and the monitor pressure regulator 14 is reached. Since the pressure regulating operation is started by, the pressure of the secondary side pipe line 2 does not rise above the set pressure of the monitor pressure regulator 14. In this way, switching for the backup operation of the worker pressure regulator 10 by the monitor pressure regulator 14 is performed.

[0006]

In the conventional system as shown in FIGS. 5 and 6, it is necessary to provide a difference in set pressure between the governor for normal operation and the governor for backup, and the governor for regular use is required. In case of failure, the supply pressure of the secondary side pipeline may fluctuate, which may affect downstream gas consuming equipment. Further, in the two-series, two-shut-off method of FIG. 5, the shut-off valves 5 and 8 need to switch a large flow rate, and the device becomes large.

An object of the present invention is to provide a monitor type pressure regulator in which the change in gas supply pressure is small even when the backup function is switched.

[0008]

DISCLOSURE OF THE INVENTION The present invention is directed to a worker pressure regulator installed in a gas supply line for reducing the primary pressure to keep the secondary pressure constant, and an upstream side of the worker pressure regulator. In a monitor-type pressure regulator that is installed and has a monitor pressure regulator for backup when the worker pressure regulator fails, the worker pressure regulator and the monitor pressure regulator are both unloading type, and the set pressure of the worker pressure regulator and the monitor pressure regulator are Until the set pressure is set to be approximately equal and the secondary pressure reaches the preset switching pressure, connect the pilot line of the worker pressure regulator to the primary side and connect the pilot line of the monitor pressure regulator to the primary pressure line. When the gas supply pressure reaches the switching pressure, the pilot line of the worker pressure regulator is disconnected from the primary side and the pilot line of the monitor pressure regulator is connected to the primary side. A monitor system pressure regulators, characterized in that it comprises switching means that. According to the present invention, the worker pressure regulator and the monitor pressure regulator are of the unloading type, and are set so that the driving pressures become substantially equal by the pilot conduit. The switching means connects the pilot line of the worker pressure regulator to the primary side and shuts off the pilot line of the monitor pressure regulator from the primary side until the secondary pressure exceeds the set pressure and reaches the predetermined switching pressure. To do. As a result, the worker pressure regulator performs the original pressure regulating operation, and the monitor pressure regulator is opened due to a large pressure difference between the primary side and the pilot line. When the secondary side pressure reaches the predetermined switching pressure, the switching means disconnects the pilot line of the worker pressure regulator from the primary side and connects the pilot line of the monitor pressure regulator to the primary side. When the secondary pressure rises in this way, the valve body of the worker pressure regulator is abnormal, and the pressure reducing operation is not performed. Since the secondary pressure can be maintained at the set pressure by the pressure reducing operation of the monitor pressure regulator, the pressure change at the time of switching can be reduced. Further, the switching pressure can be set smaller than the set pressure. For example, when the secondary side pressure does not rise due to an abnormality in the pilot conduit or the worker pressure regulator, such as when the outlet side of the pilot conduit is clogged, it is possible to switch to the monitor pressure regulator to maintain the set pressure.

The present invention is also installed in a gas supply line,
A monitoring method regulator that includes a worker pressure regulator for reducing the primary pressure to keep the secondary pressure constant, and a monitor pressure regulator installed upstream of the worker pressure regulator for backup when the worker pressure regulator fails. In the pressure regulator, the worker pressure regulator and the monitor pressure regulator are unloading type, respectively, and are set so that the set pressure of the worker pressure regulator and the set pressure of the monitor pressure regulator are substantially equal to each other, and the secondary pressure is set to the set pressure. The pilot line of the monitor pressure regulator is cut off from the primary side until the predetermined switching pressure is exceeded, and when the gas supply pressure reaches the switching pressure, the pilot line of the monitor pressure regulator is changed to the primary side. A monitor type pressure regulator comprising a switching means connected to. According to the invention, since the pilot line of the monitor pressure regulator is shut off from the primary side until the secondary pressure reaches the switching pressure by the switching means, the monitor pressure regulator is close to the pressure of the secondary pressure line. The differential pressure between the intermediate pressure and the pressure of the primary side pipe always operates in the open state. Since the pilot line is connected to the primary side when the pressure in the secondary side line reaches the switching pressure,
The monitor pressure regulator normally operates as an unloading type pressure regulator. When the pressure on the secondary side increases in this way, the valve body of the worker pressure regulator becomes abnormal and normal operation as an unloading type pressure regulator is not performed, and it is almost in the open state. The pressure is regulated by the monitor pressure regulator. Since the monitor pressure regulator has substantially the same set value of the working pressure as the worker pressure regulator, the change in the gas supply pressure on the secondary side also becomes small.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of the main part of a city gas supply system according to an embodiment of the present invention. Between the primary-side pipeline 21 and the secondary-side pipeline 22, a worker pressure regulator 30 is provided.
Operates as an unloading type pressure regulator by utilizing the intermediate pressure generated between the restrictor 32 provided in the pilot conduit 31 and the pilot valve 33, and the secondary conduit 2
The gas supply pressure of 2 is regulated. A monitor pressure regulator 34 is provided on the upstream side of the worker pressure regulator 30, and a pilot conduit 35 thereof is also provided between the primary conduit 21 and the secondary conduit 22. A restrictor 36 is provided in the pilot line 35.
And a pilot valve 37 are provided, and an operation as an unloading type pressure regulator for the monitor pressure regulator 34 is performed by using the pressure in the middle. Shut-off valves 38 and 39 are provided upstream of the pilot conduit 31 for the worker pressure regulator 30 and the pilot conduit 35 of the monitor pressure regulator 34, respectively. The shutoff valve 38 of the pilot line 31 is normally open, and shuts off at a preset switching pressure. The shutoff valve 39 provided in the pilot line 35 is normally closed, and opens when the switching pressure is reached. The pressure of the worker pressure regulator 30 set by the pilot valve 33 and the pressure of the monitor pressure regulator 34 set by the pilot valve 37 are set to be substantially equal. When the pressure in the secondary side pipeline 22 reaches the set pressure, the pilot valves 33, 37 are switched from the open state to the closed state, the intermediate pressure rises, and the differential pressure with the primary side pipeline 21 decreases. The valve body of the worker pressure regulator 30 or the monitor pressure regulator 34 is closed. The switching pressure described above is set to a pressure higher than this set pressure.

In the low-pressure pressure regulator provided in the portion for supplying gas to the final consumer in the gas supply line, the set pressure is a gauge pressure of about 210 mmH ₂ O. Hereinafter, the pressure means a gauge pressure. The switching pressure in this case is 230-25
It is about 0 mmH ₂ O. If the part using the pressure regulator is a pressure line of about 10 kgf / cm ² · G called medium pressure, the set pressure of the monitor pressure regulator is, for example, 10 k.
gf / cm ² · G, switching pressure is 11 kgf / cm
Is about ² · G.

FIG. 2 shows the operating characteristics of the embodiment of the invention of FIG. 1 in comparison with a conventional monitor type pressure regulator. FIG.
(1) shows the operating characteristics of the embodiment of the invention of FIG. 1, in which the secondary side pressure is only momentarily increased at the time of switching at time t0, and after switching, the pressure that is almost the same as before switching is maintained. To do. Such an instantaneous increase in pressure is smoothed by the conduit resistance on the secondary side of the pressure regulator and hardly affects gas consumption equipment. In the backup switching by the conventional monitor type pressure regulator shown in FIG. 2 (2), the secondary pressure is different before and after the switching, and rises especially after the switching. Normally, the pressure difference can be stopped to such an extent that it does not cause a significant effect even if it rises, but for gas consuming equipment that requires precise consumption management, readjustment is necessary.

If the switching pressure is set to about 100 mmH ₂ O, it is possible to cope with a decrease in the secondary pressure. Fluctuations are not desirable for gas consuming equipment even within the range of supply regulations. There are various possible causes for the secondary side pressure not increasing, such as clogging at the outlet side of the pilot line and the pilot line and pressure regulator.

FIG. 3 shows a structure according to another embodiment of the present invention. This embodiment of the present invention is similar to the embodiment of the invention shown in FIG. 1, and corresponding parts bear the same reference numerals. It should be noted that, although the two shut-off valves 38, 39 are used for switching in FIG. 1, the three-way valve 40 is used in this embodiment of the present invention to operate the pilot lines 31,
This is a point of switching connection or disconnection between the primary side conduit 21 and the conduit 35. The three-way valve 40 normally includes the primary side conduit 21 and the pilot conduit 31 for the worker pressure regulator 30.
Between the primary side conduit 21 and the monitor pressure regulator 34.
The pilot line 35 is disconnected. When a failure occurs in the worker pressure regulator 30 and the gas supply pressure in the secondary side conduit 22 rises to reach the switching pressure, the three-way valve 40 causes the pilot pressure conduit 35 of the monitor pressure regulator 34 to move to the primary side conduit 21. It is connected and switched so as to cut off between the pilot conduit 31 of the worker pressure regulator 30 and the primary conduit 21. The operation of the embodiment of the invention of FIG. 3 is almost the same as that of the embodiment of the invention of FIG. If an explosion-proof type three-way valve 40 is used, it is possible to cope with both cases where the switching pressure is higher or lower than the set pressure by control using an electronic circuit.

FIG. 4 shows the configuration of still another embodiment of the present invention. This embodiment of the invention is also shown in FIGS.
Similar to the embodiment of the present invention, corresponding parts are designated by the same reference numerals. It should be noted that the pilot conduit 31 for the worker pressure regulator 30 is always connected between the primary conduit 21 and the secondary conduit 22, and the pilot conduit 35 and the primary conduit of the monitor pressure regulator 34 are connected to each other. That is, only the shutoff valve 39 that connects or shuts off the passage 21 is provided. Shut-off valve 3
9 is normally closed, which allows the monitor pressure regulator 3 to
4 is normally open. When the worker pressure regulator 30 malfunctions and the gas supply pressure in the secondary side conduit 22 rises to reach the switching pressure, the shutoff valve 39 opens and the monitor pressure regulator 34.
Starts normal operation as an unloading type pressure regulator. Since the worker pressure regulator 30 is out of order, even if the pressure in the secondary side conduit 22 rises above the operating pressure, it cannot be throttled and remains open.

It is preferable that the worker pressure regulator 30 and the monitor pressure regulator 34 in each embodiment of the present invention can operate at a low differential pressure. Further, it is preferable that the pressure loss in the open state is small.

[0017]

As described above, according to the present invention, both the worker pressure regulator and the monitor pressure regulator are constituted by an unloading type pressure regulator, and whether the pilot line is connected to the primary side or cut off by the switching means. Can be switched to perform the backup operation by the monitor pressure regulator. Since the set pressures of the worker pressure regulator and the monitor pressure regulator are substantially equal, the change in the secondary pressure can be reduced even if the backup function is switched.

Further, according to the present invention, the worker pressure regulator and the monitor pressure regulator are respectively constituted by unloading type pressure regulators, and the pilot line and the primary side of the worker pressure regulator are connected or disconnected by the switching means. When the worker pressure regulator is operating normally, the pilot line of the monitor pressure regulator is cut off from the primary side by the switching means, and the monitor pressure regulator is opened. When the worker pressure regulator malfunctions and the pressure in the secondary side line rises to the switching pressure, the switching means connects the pilot line of the monitor pressure regulator to the primary side line,
The unloading type control on the gas supply pressure of the secondary side pipe by the monitor pressure regulator is started. Since the set pressures of the worker pressure regulator and the monitor pressure regulator are almost the same, it is possible to reduce the change in the gas supply pressure to the secondary side pipe line at the time of switching.

[Brief description of drawings]

FIG. 1 is a partial piping system diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a graph showing operating characteristics of the embodiment of the invention shown in FIG.

FIG. 3 is a partial piping system diagram showing a schematic configuration of another embodiment of the present invention.

FIG. 4 is a partial piping system diagram showing a schematic configuration of still another embodiment of the present invention.

FIG. 5 is a partial piping system diagram showing a schematic configuration of a conventional 2-series 2-interruption type pressure regulator.

FIG. 6 is a partial piping system diagram showing a schematic configuration of a conventional monitor type pressure regulator.

[Explanation of symbols]

 21 Primary Side Pipe 22 Secondary Side Pipe 30 Worker Pressure Regulator 31,35 Pilot Line 32,36 Restrictor 33,37 Pilot Valve 34 Monitor Pressure Regulator 38,39 Shutoff Valve 40 Three Way Valve

Claims (2)

[Claims] 1. A worker pressure regulator installed in a gas supply line for reducing the primary pressure to maintain a constant secondary pressure, and a worker pressure regulator installed upstream of the worker pressure regulator when a worker pressure regulator fails. In the monitor type pressure regulator equipped with the monitor pressure regulator for backup, the worker pressure regulator and the monitor pressure regulator are unloading type so that the set pressure of the worker pressure regulator and the set pressure of the monitor pressure regulator are almost equal. The pilot line of the worker pressure regulator is disconnected from the primary side by connecting the pilot line of the worker pressure regulator to the primary side until the secondary pressure reaches the preset switching pressure. When the pressure reaches the switching pressure, switching means for disconnecting the pilot line of the worker pressure regulator from the primary side and connecting the pilot line of the monitor pressure regulator to the primary side is included. Monitor system pressure regulators to butterflies. 2. A worker pressure regulator for reducing the primary pressure to keep the secondary pressure constant, which is installed in the gas supply line, and is installed upstream of the worker pressure regulator, and when the worker pressure regulator fails. In the monitor type pressure regulator equipped with the monitor pressure regulator for backup, the worker pressure regulator and the monitor pressure regulator are unloading type so that the set pressure of the worker pressure regulator and the set pressure of the monitor pressure regulator are almost equal. The pilot line of the monitor pressure regulator is shut off from the primary side until the secondary pressure exceeds the set pressure and reaches a predetermined switching pressure, and the gas supply pressure reaches the switching pressure. A monitor type pressure regulator, comprising switching means for connecting a pilot line of the monitor pressure regulator to the primary side at a time point.