JP3894646B2 - Pressure regulating mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure regulating mechanism that allows a fluid to flow while adjusting a fluid pressure by a governor provided at a connection portion between a primary side pipe and a secondary side pipe, and is used for supply pipes for city gas, industrial gas, etc. It is.
[0002]
[Prior art]
Conventionally, as this type of pressure regulating mechanism, the governor is opened by a decrease in the pressure to be detected, and the pressure detection unit is connected to the secondary side pipe via an adjustment pipe. On the upstream side of the governor, a slam shut valve, which is an emergency shut-off valve for preventing pressure increase, was provided. Further, the primary side pipe and the secondary side pipe are connected by a pilot adjustment pipe, and a throttle valve and a pilot governor that opens due to a decrease in the secondary side pressure are interposed between the pilot adjustment pipe, The valve is opened by a decrease in the pressure detected by the governor, and the pressure detection part is connected to the intermediate portion between the throttle valve of the pilot adjustment pipe and the pilot governor via the main governor adjustment pipe. A slam shut valve, which is an emergency shut-off valve for preventing pressure increase, is provided on the upstream side of the main governor.
[0003]
And the connecting part side with the secondary side piping of the adjusting pipe in the former or the pilot adjusting pipe in the latter needs to be guided from the straight pipe part, so it is usually buried in the ground, such as an earthquake The adjustment tube or the like may be damaged due to the stress caused by.
[0004]
[Problems to be solved by the invention]
When the adjusting pipe is damaged, the pressure detected via the adjusting pipe drops in the former, and the governor opens, and the secondary pipe is boosted by opening the valve. It will leak. At this time, there is a possibility that the slam shut valve operates due to the pressure increase, but it is not possible to prevent the gas in the secondary side pipe from leaking from the damaged portion of the adjusting pipe.
On the other hand, in the latter case, if the pilot adjustment pipe is damaged, the pressure detected via the adjustment pipe drops, the pilot governor opens, the pressure on the upstream side drops, and the detection is detected via the main governor adjustment pipe. As a result, the main governor is opened, the secondary side pipe is boosted by opening the valve, and the gas leaks from the damaged portion of the adjusting pipe. At that time, even if the slam shut valve operates, it is not possible to prevent the gas in the secondary side pipe from leaking from the damaged portion of the pilot adjustment pipe.
[0005]
Accordingly, an object of the present application is to provide a highly-safe pressure regulating mechanism that can prevent fluid leakage from the damaged portion even if the governor adjusting tube or the like is damaged.
[0006]
[Means for Solving the Problems]
The characteristic configuration of the present invention for achieving the above-described object is that the governor includes: a governor provided at a connection portion between the primary side pipe and the secondary side pipe; The valve is opened due to a decrease in the pressure to be detected, and the pressure detection part is connected to the secondary side pipe via the adjustment pipe, and the connection part to the secondary side pipe in the adjustment pipe near portion, while preventing excessive flow of fluid to the adjusting tube, usually at the time of there in that is provided with a valve mechanism in the open state.
[0007]
On the other hand, the characteristic configuration of another invention is that in the pressure regulating mechanism that distributes the fluid while adjusting the fluid pressure by the main governor provided at the connection portion between the primary side pipe and the secondary side pipe, the primary side pipe and the secondary side pipe are arranged. The secondary side pipe is connected by a pilot adjustment pipe, and a throttle governor and a pilot governor that opens due to a drop in the secondary side pressure are interposed between the pilot adjustment pipes, and the pressure detected by the main governor is reduced. The pressure detection unit is connected to the intermediate portion between the throttle valve and the pilot governor of the pilot adjustment pipe via a main governor adjustment pipe, and the secondary side pipe in the pilot adjustment pipe the connecting portion vicinity portions with, while preventing excessive flow of fluid to the pilot adjusting tube, usually at the time of there in that is provided with a valve mechanism in the open state.
The effects are as follows.
[0008]
[Function and effect]
According to the characteristic configuration of the present invention, as described above, when the adjusting pipe is broken, the pressure detected through the adjusting pipe is reduced, the governor is opened, and the secondary side pipe is boosted by opening the valve. when fluid leaks from a damaged portion of the adjusting tube, the connecting portion vicinity of the said secondary pipe in the adjusting tube, while preventing excessive flow of fluid to the adjusting tube, usually at the time of the open state the valve Since the mechanism is provided, leakage of fluid can be prevented by preventing excessive flow of fluid to the damaged portion of the adjusting pipe. In addition, since the valve mechanism is normally open, the pressure can be guided to the pressure detector of the governor via the adjusting pipe provided with the valve mechanism, and the pressure regulation function can be maintained.
As a result, even if the governor adjusting pipe or the like is broken, it is possible to provide a highly safe pressure regulating mechanism that can prevent fluid leakage from the broken portion.
[0009]
On the other hand, according to the characteristic configuration of another invention, as described above, when the pilot adjustment pipe is broken, the pressure detected through the adjustment pipe is reduced, the pilot governor is opened, and the upstream side is reduced in pressure. When the pressure detected via the main governor adjustment pipe drops, the main governor opens and the secondary pipe is boosted by opening the valve, and fluid leaks from the damaged part of the pilot adjustment pipe. the connecting portion vicinity of the said secondary pipe in the tube, while preventing excessive flow of fluid to the pilot adjusting tube, since the normal is provided with a valve mechanism in the open state, damage to the pilot adjusting tube By preventing excessive fluid flow to the part, fluid leakage can be prevented. In addition, since the valve mechanism is normally open, the pressure can be introduced to the pressure detecting portion of the pilot governor via the adjustment pipe provided with the valve mechanism, and the pressure regulation function by the pilot adjustment pipe can be maintained. it can.
As a result, even if the governor adjusting pipe or the like is broken, it is possible to provide a highly safe pressure regulating mechanism that can prevent fluid leakage from the broken portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, a governor 3 is provided at a connection portion between the primary side pipe 1 and the secondary side pipe 2, thereby adjusting the fluid pressure from the primary side pipe 1 to the secondary side pipe 2. Circulate fluid to The target fluid is, for example, city gas (hereinafter simply referred to as gas) g, and there is a demand area for city gas downstream of the secondary side pipe 2. And this secondary side piping 2 respond | corresponds to gas demand, gas flows out to the downstream side, and when a gas is not supplied from a primary side, a pressure drop will be caused on the secondary side.
[0011]
The governor 3 is a normally open diaphragm type linear motion governor, and the valve body 3b is spring-biased in the opening direction to open by a drop in pressure detected by the pressure detecting unit 3a. The pressure detection unit 3a is connected to the secondary side pipe 2 via the adjustment pipe 4, and pressure can be introduced from the secondary side pipe 2 to the pressure detection unit 3a. Further, the pressure detection unit 3a is a closed space, and has a structure in which no gas flows in from the primary side pipe 1.
[0012]
A valve mechanism 5 that is normally open is provided in the vicinity of the connecting portion between the adjusting pipe 4 and the secondary pipe 2 while preventing excessive fluid flow to the adjusting pipe 4. As a specific structure of the valve mechanism 5, for example, as shown in FIG. 2, a valve body 5 a that displaces according to the fluid flow state is provided. Examples include a structure in which the valve is closed in contact with 5b, and a biasing means 5c for adjusting the degree of displacement.
[0013]
A slam shut valve 6 which is an emergency shut-off valve for preventing pressure increase is provided on the upstream side of the governor 3, and the pressure guiding pipe 7 is connected to the secondary side pipe 2 so that it can be shut off at abnormal pressure increase. It is like that. The connection side of the adjustment pipe 4 to the secondary side pipe 2 and the connection side of the valve mechanism 5 and the pressure guide pipe 7 to the secondary side pipe 2 are buried in the soil.
[0014]
Next, the operation of the pressure regulating mechanism will be described.
Normally, the secondary pipe 2 flows downstream in response to gas demand, and when the gas supply from the primary side is insufficient, a pressure drop occurs on the secondary side, which is in an open state. The pressure is guided to the pressure detector 3 a of the governor 3 through the valve mechanism 5 and the adjustment pipe 4. And by the fall of the pressure detected by the pressure detection part 3a, the valve body 3b is urged | biased by a spring in an opening direction, and a valve is opened, the pressure drop in a secondary side recovers, and a pressure regulation function works.
On the other hand, when the adjusting pipe 4 is damaged, the pressure detected through the adjusting pipe 4 is lowered, the governor 3 is opened, and the secondary side pipe 2 is boosted by opening the valve. In order to prevent an excessive flow of the fluid to the fluid, it is possible to prevent the fluid from leaking from the damaged portion of the adjustment pipe 4. Since the secondary side pipe 2 is boosted, the slam shut valve 6 is closed to prevent excessive pressure from being generated on the consumer side at the end of the secondary side pipe 2.
[0015]
[Second Embodiment]
As shown in FIG. 3, a main governor 13 is provided at a connection portion between the primary side pipe 1 and the secondary side pipe 2, whereby the primary side pipe 1 to the secondary side pipe are adjusted while adjusting the fluid pressure. Flow fluid to 2. The target fluid is, for example, city gas (hereinafter simply referred to as gas) g, and there is a demand area for city gas downstream of the secondary side pipe 2. And this secondary side piping 2 respond | corresponds to gas demand, gas flows out to the downstream side, and when a gas is not supplied from a primary side, a pressure drop will be caused on the secondary side.
[0016]
The primary side pipe 1 and the secondary side pipe 2 are connected by a pilot adjustment pipe 10, and a throttle valve 11 and a pilot governor 12 are interposed between the pilot adjustment pipes 10. The pilot governor 12 is a normally open diaphragm type linear motion governor that opens when the secondary side pressure decreases. The pressure detection unit 12a communicates with the secondary side, and the valve body 12b is spring-biased in the opening direction to open due to a decrease in pressure detected there. The throttle valve 11 only needs to have a function of limiting the flow rate from the upstream side to a predetermined amount, and a variable flow rate valve can also be used.
[0017]
The main governor 13 is a normally open diaphragm-type linear motion governor, and the valve body 13b is spring-biased in the opening direction to open by a drop in pressure detected by the pressure detection unit 13a. The pressure detector 13a is connected between the throttle valve 11 and the pilot governor 12 of the pilot adjustment pipe 10 via the main governor adjustment pipe 14, and can introduce pressure from the pilot adjustment pipe 10 to the pressure detection section 13a. It is.
[0018]
A valve mechanism 5 that is normally open is provided in the vicinity of the connecting portion between the pilot adjustment pipe 10 and the secondary pipe 2 while preventing excessive fluid flow to the pilot adjustment pipe 10. As a specific structure of the valve mechanism 5, for example, as shown in FIG. 4, a valve body 5 a that is displaced according to the flow direction of the fluid is provided, and the valve body 5 a contacts the valve seat 5 b when backflow occurs. And various check valves that close the valve and those provided with biasing means 5c for adjusting the degree of displacement.
[0019]
A slam shut valve 6 that is an emergency shut-off valve for preventing pressure increase is provided on the upstream side of the main governor 13, and the pressure guiding pipe 7 is connected to the secondary side pipe 2, so that it can be shut off during abnormal pressure increase. It is like that. The connection side of the pilot adjustment pipe 10 to the secondary side pipe 2 and the connection side of the valve mechanism 5 and the pressure guiding pipe 7 to the secondary side pipe 2 are buried in the soil.
[0020]
Next, the operation of the pressure regulating mechanism will be described.
Normally, the secondary pipe 2 flows downstream in response to gas demand, and when the gas supply from the primary side is insufficient, a pressure drop occurs on the secondary side, which is in an open state. The pressure is introduced to the pressure detector 12 a of the pilot governor 12 through the valve mechanism 5 and the pilot adjustment pipe 10. When the valve body 12b is spring-biased in the opening direction due to a drop in pressure detected by the pressure detector 12a, the upstream side of the pilot governor 12 is depressurized, and this is the main governor adjustment pipe. 14 through the pressure detector 13 a of the main governor 13. As a result, due to a decrease in the pressure detected by the pressure detector 13a, the valve body 13b is spring-biased in the opening direction, the main governor 13 is opened, and the pressure drop on the secondary side is recovered to regulate the pressure. Function works.
On the other hand, when the pilot adjustment pipe 10 in the soil is broken, the pressure detected through the adjustment pipe 10 is reduced, the pilot governor 12 is opened, the pressure on the upstream side is reduced, and the main governor adjustment pipe 14 is The main governor 13 opens and the secondary side pipe 2 is boosted by opening the valve. However, since the valve mechanism 5 is provided, fluid to the damaged portion of the pilot adjustment pipe 10 is opened. By preventing excessive flow of fluid, fluid leakage can be prevented. Since the secondary side pipe 2 is boosted, the slam shut valve 6 is closed to prevent excessive pressure from being generated on the consumer side at the end of the secondary side pipe 2.
[0021]
[Another Example]
Another embodiment of the present application will be described below.
(B) In the previous embodiment, an example of using a normally open diaphragm type linear motion governor as a governor (including a main governor and a pilot governor) has been shown. However, as long as the valve opens due to a decrease in pressure to be detected. In addition, various types can be used.
[0022]
(B) In the previous embodiment, an example in which a slam shut valve is used has been described. However, the configuration is not necessarily required in order to prevent leakage of fluid from the adjustment pipe, and may be omitted as appropriate.
[0023]
(C) In the previous embodiment, the example of the city gas (gas) flowing through the piping has been shown, but this may be any fluid as long as it is a fluid, and these are collectively referred to as fluid.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example (first embodiment) of a pressure regulating mechanism of the present invention. FIG. 2 is a schematic diagram showing a main part of an example (first embodiment) of a pressure regulating mechanism of the present invention. FIG. 4 is a schematic diagram showing an example (second embodiment) of the pressure regulating mechanism of the present invention. FIG. 4 is a schematic diagram showing the main part of an example (second embodiment) of the pressure regulating mechanism of the present invention.
DESCRIPTION OF SYMBOLS 1 Primary side piping 2 Secondary side piping 3 Governor 3a Pressure detection part 4 Adjustment pipe 5 Valve mechanism 10 Pilot adjustment pipe 11 Throttle valve 12 Pilot governor 13 Main governor 13a Pressure detection part 14 Main governor adjustment pipe g Fluid

Claims (2)

A governor provided at a connection portion between the primary side pipe and the secondary side pipe, and a pressure regulating mechanism for circulating the fluid while adjusting the fluid pressure,
The governor is opened by a decrease in the pressure to be detected, and the pressure detection part is connected to the secondary side pipe via an adjustment pipe,
Wherein the connecting portion vicinity of the said secondary pipe in the adjustment tube, while preventing excessive flow of fluid to the adjusting tube, Sei圧mechanism normal that is provided with a valve mechanism in the open state. A pressure regulating mechanism that circulates fluid while adjusting fluid pressure by a main governor provided at a connection portion between a primary side pipe and a secondary side pipe,
The primary side pipe and the secondary side pipe are connected by a pilot adjustment pipe, and a throttle valve and a pilot governor that opens due to a drop in the secondary side pressure are interposed between the pilot adjustment pipes,
The main governor is opened by a decrease in the pressure to be detected, and the pressure detection unit is connected between the throttle valve of the pilot adjustment pipe and the pilot governor via the main governor adjustment pipe,
Wherein the connecting portion vicinity of said secondary pipe of the pilot adjusting tube, while preventing excessive flow of fluid to the pilot adjusting tube, Sei圧mechanism normal that is provided with a valve mechanism in the open state.

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