JPS6266137A - Inspection method for leakage of piping - Google Patents

Abstract

PURPOSE:To easily and quickly detect a leakage part with a high accuracy by sealing the inside of a piping with a basic gas, applying an organic reactive indicator to a part to be inspected, and blowing an untoxicant gas into the piping after a check. CONSTITUTION:A water feed pipe 1 and a hot water feed pipe 2 are connected by a rubber hose 3, and bomb 5, 6 are connected to an injection part 4 so that they can be switched. By opening the bomb 6, the inside of a piping is purged by a nitrogen gas, an organic reaction indicator is applied uniformly to a part to be inspected, and by opening the bomb 5, a mixed gas of an ammonia gas and a nitrogen gas is fed, and when an ammonia concentration shown by a detector connected to a pipe end 7 becomes >=500ppm, the bomb 5 is closed. When the inspection is ended, the mixed gas is exhausted by feeding air into the pipe. A leakage inspecting agent reacts to a basic gas and causes sharply coloring or discoloring, therefore, a leakage part can be detected easily and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a leakage inspection method for water supply piping, air conditioning equipment piping, etc.

[Conventional technology]

In general, a leakage inspection method for welded parts, threaded parts, flanges, etc. of pipes such as waterworks and air conditioning ducts involves injecting water or air under pressure and detecting leakage points with the naked eye.

However, such a method has the drawbacks of poor workability and extremely low detection accuracy.

For example, the water pressure method is generally used to inspect water supply leaks, but it is difficult to transport large amounts of water into buildings under construction where piping work has been completed, and normal inspections only involve water supply piping and hot water supply piping. They are connected all at once using vinyl chloride pipes, but the water pressure is as high as 10 kg/crl, so to prevent them from coming off during the inspection, it is necessary to connect them the day before and ensure sufficient adhesion. There were problems with workability, such as the fact that water was not sufficiently distributed in the piping and air remained, so air removal was essential, and that it took more than 30 minutes to raise the water pressure to 10 kg/cJ.

Furthermore, the inspection involves visually observing the location of water leakage.
It was difficult to detect pinholes in welding, and the detection accuracy was quite low because the pipes were located in dark places such as floors, walls, and ceilings (with poor footing). The same can be said when testing by applying

[Problem that the invention seeks to solve]

The object of the present invention is to enable leakage inspection of piping to be performed easily, accurately, and in a short time.

[Means for solving problems]

This idea involves sealing a basic gas inside the pipe, applying a leak detection agent based on an organic reactive indicator that reacts to the basic gas to the inspection point on the outside of the pipe, and detecting the leak point by color development or discoloration. After inspection, non-toxic gas is blown into the pipes to discharge basic gas.

[Effect]

This invention has the following effects.

(1) Since the leak detection agent has extremely high detection sensitivity, the pressure of filling the basic gas may be low. Therefore, in the case of water supply, the water supply piping and the hot water supply piping need only be connected immediately before the inspection, and the connecting pipes can be made of something as soft as a rubber hose.

Since the pressure is low, the time required to raise the pressure is short.

Furthermore, since the basic gas is usually stored in a cylinder, it is not only easy to handle, but also does not require air removal in the hydraulic method since it is a gas.

(2) Since the leak detection agent clearly develops or changes color even in the slightest amount of basic gas, the leak detection accuracy is extremely high even in places with poor working conditions.

(3) After the inspection, the basic gas is sufficiently exhausted, so there is no harm to the human body.

〔Example〕

An embodiment of this invention will be described based on the drawings.

The drawing schematically shows a leak test for water supply piping.

Connect the water supply pipe (1) and the hot water supply pipe (2) with a rubber hose (3), use the other end of the water supply pipe (1) as an inlet (4), and insert a cylinder (5) containing a mixed gas of ammonia gas and nitrogen gas. ) and a cylinder (6) containing nitrogen gas are switchably connected. Also, connect the other end of the hot water supply pipe (2) to the outlet (
As 7), an ammonia gas concentration detector (not shown) is attached via a pressure gauge (8) and a detection nozzle.

Since the branches and leaves of the pipe are usually left open, a sealing camp (9) is attached.

Ammonia gas is used as the basic gas, and in this embodiment, a mixed gas of ammonia gas and nitrogen gas is used.

The concentration of ammonia gas in the cylinder (5) is 10. OOO
It is ppm. It goes without saying that the basic gas is not limited to ammonia gas.

A known agent containing an organic reactive indicator as a main ingredient is used as a leakage detection agent. Organic reactive indicators are, for example, PH indicators such as bromophenol blue or diazo components and coupling components. These react with basic gases and develop or change color to clearly identify the location of the leak. In addition to the detection substance, the leak detection agent consists of a coating agent, inorganic powder, solvent, etc.

Next, the inspection method will be explained one by one.

(1) Pretreatment a) Remove impurities such as dust, water, oil, etc. from the surface of the pipe joint using a cleaning solution.

b) Purge moisture, rubber, etc. in the piping by opening the cylinder (6) and releasing nitrogen gas.

(2) Inspection a) A leak testing agent is uniformly applied to the inspection location, and a known ammonia gas leak detection alarm (10) is installed and activated.

b) Open the cylinder (5) and send the mixed gas, and when the ammonia gas concentration reaches 500 ppm or more, close the cylinder (5), then open the cylinder (6) and send the nitrogen gas to 2-5
Adjust the pressure to kg/cA.

c) Leave it for at least 5 minutes.

(3) Judgment a) If the buzzer of the ammonia leak detection alarm (10) does not operate, the test is passed.

b) Only when the buzzer is activated, disconnect the alarm (1o) and check whether the leakage test agent has developed a color (for example, blue-purple).

If not, you pass.

(4) Post-processing a) Remove the leakage test agent from the inspection area with a rag.

b) A compressor blows air into the piping to exhaust the mixed gas containing ammonia gas. Ammonia gas is o
It ends when it reaches ppm.

In addition, in this embodiment, an ammonia gas leak detection alarm (1
Since 0) is used in combination, there is no need to inspect all inspection points, which has the effect of increasing work efficiency.

In leak inspection of air conditioning equipment piping, the pressure inside the piping is set to 2 kg.
/cn(, except for changing it to the above method.

〔Effect of the invention〕

In this invention, basic gas is sealed inside the pipe, and a leak detection agent is applied to the outside surface of the pipe, and the leakage location is discovered by color development or discoloration, so workability and detection accuracy are significantly improved compared to conventional water pressure methods. .

Moreover, since the basic gas is exhausted by blowing non-toxic gas, there is no danger to the human body.

[Brief explanation of drawings]

The drawing is a schematic diagram of leakage inspection of water supply piping. (1)...Water supply piping (2)...Hot water supply piping (5)・
・・Cylinder of mixed gas of ammonia gas and nitrogen gas

Claims (1)

[Claims] 1. Fill the pipe with basic gas, apply a leak test agent whose main ingredient is an organic reactive indicator that reacts with basic gas to the inspection point on the outside of the pipe, and detect and inspect the leak point by color development or discoloration. A method for inspecting leaks in piping, characterized by blowing non-toxic gas into the rear piping to discharge basic gas.