JPH0868715A - Method and apparatus for detecting gas leakage - Google Patents

Abstract

PURPOSE: To obtain method and apparatus for detecting leakage of gas from a concerned inner pipe accurately under a live state. CONSTITUTION: A flow rate take-out means is fixed to a service tees 3 coupled between a supply pipe 4 and a concerned inner pipe 4a. A flow rate of gas taken out by the take-out means is measured by a gas flow rare measuring means and a gas meter 5 simultaneously. A decision is made than the gas has leaked from the concerned inner pipe 4a if the flow rate measured by the flow rate measuring means is lower than the flow rate measured by the gas meter 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas conduit (hereinafter referred to as "outer lamp inner pipe") that passes through a supply pipe branched from a main gas branch pipe and then passes through a customer's site to a gas meter. "
Said) for the inspection of gas leaks from

[0002]

2. Description of the Related Art As a method for inspecting a gas leak from an outer tube of a lamp, there is a regular patrol inspection once every three years, which is defined by safety standards. Further, gas leaks from the lamp inner tube may be noticed by odors by gas meter readers and consumers.

[0003]

However, since all of the above-mentioned gas leak inspections are perceived by humans due to odors, minute leaks are difficult to detect and gas leaks go underground, so that there is a local problem. There is a problem that there is a gas odor in a place where it is outside the room, detection is delayed, and it takes time to identify the location. It is an object of the invention to propose a method and a device for the simple and reliable inspection of gas leaks from the lamp inner tube.

[0004]

The method and apparatus for inspecting for gas leakage from the inner tube of the lamp according to the present invention are as follows.

1. A gas flow rate measuring means is installed on the upstream side of the outer lamp inner pipe branched from the main branch pipe via the supply pipe to create a gas flow from the main branch pipe to the inner lamp pipe side via the gas meter. A gas leak detection method for determining that there is a gas leak from an inner tube of a lamp when there is a difference of a certain value or more between the flow rate of gas measured by the measuring means and the flow rate of gas measured by a gas meter.

2. Gas flow branching means mounted on the upstream side of the inner tube outside the lamp, gas flow rate measuring means for measuring the flow rate of the gas branched by the gas flow branching means, gas flow rate value and gas meter measured by the gas flow rate measuring means A gas leak detection device comprising: a gas leak determination means that compares the gas flow rate value measured in step 1 above and determines that there is a gas leak from the inner tube of the lamp when there is a difference in flow rate between them.

3. A mounting means that can be fitted into a blind plug fitting port of service cheese that connects the supply pipe and the outer lamp pipe, and a gas return port is formed in a part of the service cheese. It can be inserted and expands the gas stopper attached to the tip to stop the gas flowing to the side of the light cheese inner tube connection port side of the service cheese, while taking out the flow rate for temporarily taking out the gas through the gas stopper to the outside of the mounting means. Means for gas flow branching.

[0008]

When performing a leak inspection, first, the blind plug of the service cheese attached to the connection portion between the supply pipe and the lamp inner pipe is removed, and the gas flow branching device is attached to the gas cheese using the mounting means. The gas flow rate measuring means is connected to.

Next, the gas flow outlet of the gas flow branching device is lowered into the service cheese, and then the gas stopper is expanded to stop the gas flowing into the service cheese.

In this state, when the test cook and the gas appliance or the test port of the lamp inner tube end are opened, the gas branched from the main branch into the supply tube is the service cheese gas outflow means → gas flow rate measurement. Means → return port for fittings → service cheese connection port → outer lamp inner tube → gas meter → inner lamp inner tube.

The gas flow rate measuring means measures the gas flow rate during this flow, and at the same time, the gas meter also measures the gas flow rate.

The gas leak determining means compares the gas flow rate values measured by the gas flow rate measuring means and the gas meter, and when the difference is equal to or more than a certain value excluding an error, it is determined that there is a gas leak from the lamp inner tube. A determination is made and this is displayed on the display means, for example.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

In FIG. 1, 1 is a main branch pipe and 2 is a main branch pipe 1.
A service cheese for branching for branching the supply pipe 4 attached to 3, a service cheese for connection attached between the supply pipe 4 and the inner tube 4a outside the lamp, 5 is a gas meter, 6 is a meter cock, and 7 is The lamp inner tube, 8 is an inspection port. Reference numeral 9 is a gas leak determining means, which is a gas flow rate measuring means 9 inside.
a is incorporated. Reference numeral 10 is an inlet gas conduit, and 11 is an outlet gas conduit.

FIG. 2 shows the relationship between the service cheese 3 and the gas leakage determination means 9. The service cheese 3 has a mounting port 12 for the supply pipe 4 formed in the lower part thereof, and a lamp outer inner pipe in the middle horizontal direction. A connection port 13 is formed, and a blind plug mounting port 14 is formed on the upper portion.
Is formed. 15 is a mounting means, which has a structure in which a flow rate extraction means insertion port 16 is formed in the center and a gas return port 17 is formed in the side part, and this mounting means 15 is the service cheese 3 described above. It is attachable to and detachable from the blind plug mounting opening 14. Reference numeral 18 denotes the inner tube 1 inserted from above into the flow rate extraction means insertion port 16 of the mounting means 15.
A gas take-out means having a double pipe structure composed of 9 and an outer pipe 20, and a gas stopper 21 for closing the attachment port 12 of the service cheese 3 is attached to the lower end 19b of the inner pipe 19. 22 is a washer, 23 is an O-ring, 24 is a screw member attached to the upper end of the outer pipe 20, and this screw member 24 is screwed with a screw cut near the upper end 19a of the inner pipe 19 side. By rotating the screw member 24, the inner pipe 19 can be moved up and down to increase or decrease the outer diameter of the gas stopper 21.

Next, an inspection method using the above-mentioned leakage inspection device will be described with reference to FIGS. First, the flow rate extraction means 18 is inserted into the service cheese 3 using the mounting means 15, the inlet gas conduit 10 of the gas leakage determination means 9 is connected to the upper end 19a of the inner pipe 19, and the outlet side is connected to the gas return port 17. Connect the gas conduit 11. Next, by turning the screw member 24 and pulling up the inner pipe 19, the diameter of the gas stopper 21 is expanded to close the attachment port 12 of the service cheese 3. Then, an inspection cock (not shown) of the gas leak determination means 9 is opened, and the gas in the main branch 1 is fed into the main branch 1 → branch service cheese 2 → supply pipe 4 → service cheese 3 inner pipe 19 → entrance. Side gas conduit 10 → inspection cock (not shown) → gas flow rate measuring means 9a in gas leak determination means 9 → outgoing gas conduit 11
→ Gas return port 17 → Service cheese 3 → Outer lamp inner tube connection port 13 → Outer lamp inner tube 4a → Meter cock 6 → Gas meter 5 →
Flush to gas appliances.

FIG. 3 shows a flow of the above-mentioned leak inspection. The flow rate take-out means 18 is attached to the service cheese 3 and the gas leak judging means 9 is attached (step 10).
0), the gas flow is measured by the gas flow rate measuring means 9a and the gas meter 5 in the gas leak determining means 9, and the gas leak determining means 9 is used.
When the flow rate value measured by the gas meter 5 is smaller than the flow rate value measured by the gas flow rate measurement means 9a by comparing the gas flow rate measurement means 9a (service cheese measurement flow rate) with the flow rate value measured by the gas meter 5. It is determined that there is leakage, and if they are the same, it is determined that there is no leakage (step 10
2). In the case of the example, the gas leak is simultaneously inspected while using the gas appliance.
May be opened to create a gas flow in the inner tube 4a of the lamp to perform a leak test. It is also possible to determine that there is a gas leak when the meter cock 6 is closed and a gas pressure is applied from the main branch 1 side to the inside of the lamp outer tube, and the gas flow rate measuring means 9a measures the flow rate at this time.

[0018]

As described above, according to the present invention, the gas flow rate measuring means is attached to the service cheese connecting the supply pipe and the lamp outer inner tube to flow the gas into the lamp outer inner tube. The measurement was performed at two locations, the measuring means and the gas meter, and it was determined from the difference between the measured values whether there was a leak or not. As a result, it is possible to detect gas leaks more reliably than conventional odor tests, and at the time of patrol inspection for security, go around each customer with gas leak judgment means and gas flow branching means and service it. Since it can be attached to cheese for leak inspection, it will improve the work efficiency significantly compared to the conventional method of inspecting for gas leakage while sniffing the odor along the inner tube of the lamp. You can In addition, gas leaks that cannot be detected by the odor test can be reliably detected. Next, according to the present invention, a leak test can be performed even while the gas appliance is in use (in a live tube state).
No inconvenience to customers.

[Brief description of drawings]

FIG. 1 is an explanatory view of an inspection method of the present invention and its apparatus.

FIG. 2 is an explanatory view of gas flow branching means.

FIG. 3 is an explanatory diagram of a leakage inspection flow.

[Explanation of symbols]

 1 main pipe 2 service cheese for branching 3 service cheese 4 supply pipe 4a light outer pipe 5 gas meter 6 meter cock 7 inner pipe 8 test port 9 gas leak judging means 9a gas flow rate measuring means 10 inlet gas conduit 11 outlet gas conduit 12 Mounting Port 13 Light Inner Tube Connection Port 14 Mounting Port 15 Mounting Means 16 Insertion Port 17 Return Port 18 Flow Rate Extraction Unit 19 Inner Pipe 20 Outer Pipe 21 Gas Stopper 22 Washer 23 O-ring 24 Screw Member

Claims (3)

[Claims] 1. A gas flow rate measuring means is attached to an upstream side of an outer lamp inner pipe branched from the main branch pipe via a supply pipe so that a gas flow from the main branch pipe to a lamp inner pipe side via a gas meter. That is, it is determined that there is a gas leak from the lamp inner tube when there is a difference of a certain value or more between the flow rate value of the gas measured by the gas flow rate measuring means and the flow rate value of the gas measured by the gas meter. Gas leak detection method. 2. A gas flow branching unit attached to the upstream side of the lamp inner tube, a gas flow rate measuring unit for measuring the flow rate of the gas branched by the gas flow branching unit, and a gas measured by the gas flow rate measuring unit. Gas leakage detection means that compares the flow rate value of the gas with the gas flow rate value measured by the gas meter and determines that there is a gas leak from the inner tube of the lamp when there is a flow rate difference above a certain level. apparatus. 3. A mounting means which can be fitted to a blind plug fitting port of service cheese for connecting a supply pipe and a lamp inner pipe, and a gas return port is partially formed, It can be inserted into the service cheese and the gas stopper attached to the tip is expanded to stop the gas flowing to the side of the service cheese's outside lamp inner pipe connection, while the gas is once passed through the gas stopper to the outside of the mounting means. A gas flow branching device comprising: a flow rate extracting means for extracting.