CN111829735A - A kind of pipeline air tightness detection device and method - Google Patents

Abstract

The invention discloses a device and a method for detecting the air tightness of a pipeline, wherein the device for detecting the air tightness of the pipeline comprises an adsorption type test cabin, a vacuum pump and a vacuum degree detection device, wherein the adsorption type test cabin comprises an adsorption device and a sealing cover, and the adsorption device is arranged at an opening of the sealing cover; the vacuum pump is communicated with the sealing cover through a first pipeline, and a first valve is arranged on the first pipeline; the vacuum degree detection device is communicated with the first pipeline. The method for detecting the air tightness of the pipeline comprises the steps of firstly adsorbing an adsorption test chamber in a pipeline welding line area to be detected, enabling the adsorption test chamber to seal the pipeline welding line area to be detected, successively opening a first valve and a vacuum pump, vacuumizing the adsorption test chamber to a test value, closing the first valve and the vacuum pump, reading relevant readings of a vacuum degree detection device, and if the readings of the vacuum degree detection device are not changed to be lower than a qualified vacuum value within a certain time, meeting requirements, otherwise, not meeting the requirements.

Description

A kind of pipeline air tightness detection device and method

technical field

The invention is used in the field of air tightness detection, and in particular relates to a pipeline air tightness detection device and method.

Background technique

The water pressure inside the deep buried pressure water pipeline can reach 200m water column or even higher, and the water inside the pipeline can leak through the weld pinhole under high pressure. The leaking water leaks through the pinhole of the weld for a long time, and accumulates in the small gap between the pipe and the rock, forming high-pressure water outside the pipe. When the pipe is supplied with water, the water pressure inside and outside the pipe is equal, but due to maintenance and other reasons, when When the water supply inside the pipe suddenly stops, the water pressure in the pipe disappears, but the high pressure outside the pipe still exists. .

In order to check whether the tightness of the pipeline weld meets the requirements on site, the traditional inspection method is to conduct a closed water test of the entire pipeline, that is, to seal the two ends of the entire pipeline, inject water to pressurize the outside of the end, and check the change of water pressure over time. The range of change determines whether its tightness meets the requirements. However, for pipelines buried deep in the ground, it is very difficult to plug the pipeline, inject water, pressurize and drain the pipeline. Leaks are difficult to detect, therefore, traditional methods are not suitable for tightness inspection of deeply buried pipelines.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a device and method for detecting the air tightness of a pipeline, the detection process is more efficient, the cost is lower, and the detection result is reliable.

The technical solution adopted by the present invention to solve the technical problem is as follows: an air tightness detection device for a pipeline, comprising:

The adsorption-type test chamber is used for adsorption at the weld of the pipeline to be tested, the adsorption-type test chamber includes an adsorption device and a sealing cover, and the adsorption device is arranged at the opening of the sealing cover;

a vacuum pump, communicated with the sealing cover through a first pipeline, and the first pipeline is provided with a first valve;

The vacuum degree detection device is communicated with the first pipeline to detect the vacuum degree in the adsorption-type test chamber.

Preferably, the suction device includes a first suction cup and a second suction cup, the first suction cup is located in the second suction cup and is spaced apart from the second suction cup, and the first suction cup and the second suction cup are mutually The interval defines an adsorption chamber, and the adsorption chamber is connected with the vacuum pump through a second pipeline, and a second valve is provided on the second pipeline.

Preferably, rectangular compartment suction lips are provided on both the first suction cup and the second suction cup.

Preferably, the sealing cover is provided with a support frame for supporting the sealing cover.

Preferably, the first suction cup and the second suction cup are provided with magnetic powder.

Preferably, the vacuum degree detection device includes a U-shaped pipe, an air chamber and an air valve, one end of the U-shaped pipe is connected to the first pipeline, the other end of the U-shaped pipe is connected to the air chamber, and the U-shaped pipe is connected to the air chamber. One side of the air chamber is provided with an air valve for opening and closing the air chamber.

A method for detecting air tightness of a pipeline, comprising the following steps:

Adsorb the adsorption test chamber to the pipeline weld area to be tested;

Start the vacuum pump and evacuate the adsorption test chamber to the test value;

turn off the vacuum system;

By observing the corresponding readings of the vacuum degree detection device, the air tightness of the welded seam of the pipeline to be detected is judged.

Preferably, before the adsorption test chamber is adsorbed on the weld area of the pipeline to be inspected, the weld area of the pipeline to be inspected is processed until the roughness reaches Ra3.2 level.

Preferably, when observing the corresponding reading of the vacuum degree detection device, if the vacuum degree in the adsorption test chamber is not lower than the qualified vacuum degree value within 20 to 60 minutes, the air tightness of the weld area of the pipeline to be detected meets the requirements.

Preferably, before testing the pipeline, the adsorption test chamber is first adsorbed on a steel plate with a surface roughness of Ra3.2 level, a size not less than the test chamber, and a thickness of not less than 5mm for adsorption testing. The initial vacuum degree in the adsorption test chamber is P0, within 20 to 60 minutes, the vacuum degree value in the adsorption test chamber is P1, and (P0-k×P1) is used as the qualified vacuum degree value, where k=1～5, and the k value is based on the roughness of the pipe surface to be tested. Degree and test conditions are determined.

One of the above technical solutions has at least one of the following advantages or beneficial effects: in the detection process, the adsorption-type test chamber is first adsorbed on the pipeline weld area to be detected, so that the adsorption-type test chamber seals the pipeline weld to be detected. Open the first valve and vacuum pump successively, vacuum the adsorption test chamber to the test value, close the first valve and vacuum pump, and read the relevant readings of the vacuum degree detection device. If the readings of the vacuum degree detection device are within a certain period of time If there is no change below the qualified vacuum value, the air tightness of the pipeline weld meets the requirements, otherwise it does not meet the air tightness requirements.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings:

1 is a schematic structural diagram of an embodiment of the present invention;

Fig. 2 is the structural representation of the adsorption device in the embodiment shown in Fig. 1;

FIG. 3 is a schematic structural diagram of the vacuum degree detection device in the embodiment shown in FIG. 1 .

Detailed ways

This part will describe the specific embodiments of the present invention in detail, and the preferred embodiments of the present invention are shown in the accompanying drawings. Each technical feature and overall technical solution of the invention should not be construed as limiting the protection scope of the invention.

In the present invention, if there is a description of a direction (up, down, left, right, front and rear), it is only for the convenience of describing the technical solution of the present invention, rather than indicating or implying that the technical features referred to must have specific characteristics Orientation, construction and operation in a particular orientation, and therefore should not be construed as limiting the invention.

In the present invention, "several" means one or more, "multiple" means two or more, "greater than", "less than", "exceeding", etc. are understood as not including this number; "above", "below" and "within" " etc. are understood to include the original number. In the description of the present invention, if it is described that "first" and "second" are only used for the purpose of distinguishing technical features, it should not be understood as indicating or implying relative importance or implying the number of indicated technical features or Implicitly indicates the order of the indicated technical features.

In the present invention, unless otherwise clearly defined, words such as "set", "install" and "connect" should be understood in a broad sense, for example, it may be directly connected or indirectly connected through an intermediate medium; it may be a fixed connection or a The detachable connection can also be integrally formed; it can be a mechanical connection or an electrical connection or can communicate with each other; it can be the internal communication between the two elements or the interaction relationship between the two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solutions.

Referring to FIG. 1 and FIG. 2 , the present invention is mainly used for the detection of the air tightness of the pipeline. The following is an example of detecting the air tightness of the welded seam of the pipeline for detailed description.

The air tightness detection device of the pipeline includes an adsorption test chamber 2, a vacuum pump 3 and a vacuum degree detection device 4. The adsorption test chamber 2 includes a sealing cover and an adsorption device arranged at the opening of the sealing cover. The adsorption device is used for the adsorption test. The cabin 2 is adsorbed on the weld area of the pipeline 1 to be tested, and a sealed space is defined in the weld area of the pipeline 1 to be tested. A support frame 221 is arranged in the sealing cover to support the sealing cover, wherein the support frame 221 adopts a thickness of Made of flat steel with a width of 8mm and a width of 25mm, the steel is carbon structural steel or stainless steel, and the sealing cover can withstand an internal vacuum pressure of not less than -400kPa. The sealing cover can be set to square, round, oval or other shapes. structure. The top of the sealing cover is provided with a first connection port 222, and the vacuum pump 3 is connected to the first connection port 222 of the sealing cover through a first pipeline 5. The valve 51, the vacuum degree detection device 4 is communicated with the first pipeline 5 to detect the vacuum degree in the adsorption test chamber. The detection accuracy of the vacuum degree detection device 4 should not be less than 0.1kPa.

During the detection process, the adsorption test chamber 2 is first adsorbed on the weld area of the pipeline 1 to be tested, so that the adsorption test chamber 2 defines a chamber isolated from the outside in the weld area of the pipeline 1 to be tested, and the first valve is opened successively. 51 and the vacuum pump 3, evacuating the adsorption test chamber 2 to the test value, then close the first valve 51 and the vacuum pump 3, read the relevant reading of the vacuum degree detection device 4, if the relevant reading of the vacuum degree detection device 4 is within a certain time. If there is no change to the vacuum value below the qualified vacuum value, the air tightness of the welding seam of pipeline 1 meets the requirements, otherwise it does not meet the air tightness requirements. The specific air tightness standard requirements are as follows.

The adsorption-type test chamber 2 can be adsorbed on the pipeline 1 by means of sticking, pressing, vacuuming, etc. In the embodiment of the present invention, the adsorption-type test chamber 2 is adsorbed on the pipeline 1 by means of vacuuming, 2, the suction device includes a first suction cup 211 and a second suction cup 212, the first suction cup 211 is smaller than the second suction cup 212, the first suction cup 211 is located in the second suction cup 212 and is arranged concentrically with the second suction cup 212, the first suction cup 211 The second suction cup 212 is spaced apart from each other. The space between the first suction cup 211 and the second suction cup 212 defines an adsorption cavity 23 . The adsorption cavity 23 is provided with a second connection port 231 . The second connection port 231 passes through the second pipe. The pipeline 6 is connected with the vacuum pump 3 , and a second valve 61 is provided on the second pipeline 6 . Of course, in addition to the rectangular suction cup, the suction cup may also be a circular structure or other polygonal structure.

Referring to FIG. 2 , in some embodiments, the first suction cup 211 and the second suction cup 212 are each provided with a plurality of rectangular compartment suction lips 24 distributed at intervals, wherein the suction force of the rectangular compartment suction lip 24 reaches 5kPa, and the suction lips use water After wetting, it can be adsorbed on the pipeline 1, and the adsorption force and sealing performance of the adsorption test chamber 2 and the pipeline 1 can be improved.

In some embodiments, the first suction cup 211 and the second suction cup 212 are both provided with magnetic powder, and the connection strength between the adsorption-type test chamber 2 and the pipeline 1 can be enhanced by the magnetic force of the magnetic powder.

During the inspection process, first wet the rectangular compartment suction lip 24 with water, then attach the first suction cup 211 and the second suction cup 212 to the weld area of the pipeline 1 to be inspected, close the first valve 51 and open the second valve 61 and the vacuum pump 3, the adsorption chamber 23 is evacuated by the vacuum pump 3, so that the adsorption test chamber 2 is pressurized in the welding seam area of the pipeline 1 to be tested by atmospheric pressure, so as to ensure that the adsorption test chamber 2 is in the welding seam of the pipeline 1 to be tested. The area defines a sealed chamber that isolates the outside world, then closes the second valve 61, opens the first valve 51, evacuates the adsorption test chamber 2 to the test value through the vacuum pump 3, and observes the relevant reading of the vacuum degree detection device 4 to judge the airtightness The air tightness detection device of this kind of pipeline has higher efficiency and lower cost in the detection process, and the detection result is more reliable.

1 and 3 , the vacuum detection device 4 includes a U-shaped tube 41, an air chamber 42 and an air valve 43. One end of the U-shaped tube 41 is connected to the first pipeline 5, and the other end of the U-shaped tube 41 is connected to the air chamber 42. One side of the air chamber 42 is provided with an air valve 43 for opening and closing the air chamber 42, a scale is provided on the U-shaped pipe 41, and the U-shaped pipe 41 is filled with liquid. The change of the liquid level in 41 can visually see the change of the vacuum degree in the adsorption test chamber 2. Of course, in addition to detecting the change of the vacuum degree in the adsorption test chamber 2 by observing the change of the liquid level, the vacuum degree can also be measured. The detection device 4 is directly set as a vacuum degree detection table, and the change of the vacuum degree in the adsorption test chamber 2 can also be monitored in real time by reading the readings of the vacuum degree detection table within a predetermined time.

Referring to FIG. 1 and FIG. 3 , an embodiment of the present invention also provides a method for detecting the air tightness of a pipeline. The specific steps are as follows: cleaning the weld area of the pipeline 1 to be detected and treating the surface thereof until the roughness reaches Ra3 .2 level, which is convenient for the rectangular compartment suction lip 24 to be adsorbed, then wet the rectangular compartment suction lip 24 with water, and align the adsorption cavity 23 of the adsorption test chamber 2 with the weld area of the pipeline 1 to be tested and close to the pipeline 1, Close the first valve 51, open the second valve 61 and the vacuum pump 3, and vacuumize the adsorption chamber 23, so that the adsorption test chamber 2 is adsorbed on the weld area of the pipeline 1 to be tested, and close the second valve 61 to make the adsorption chamber 23 continue. Keep the vacuum, open the first valve 51, vacuum the sealing cover to the test value through the vacuum pump 3, when the adsorption test chamber 2 is evacuated to the test value, stabilize the voltage for at least ten minutes, then close the first valve 51 and the vacuum pump 3, By observing the change of the liquid level in the U-shaped pipe 41, it is judged whether the air tightness of the welding seam of the pipeline 1 to be tested meets the requirements. If the vacuum degree is not lower than the qualified value within 20 to 60 minutes, the air tightness of the weld area of the pipeline 1 to be tested meets the requirements, otherwise it does not meet the requirements. Of course, the vacuum degree detection device can also use a vacuum degree detection table. The specific standard requirement of air tightness is that the test value of vacuum degree is not less than one-sixth of the qualified value within 20 to 60 minutes. This detection method has a simple detection method and reliable conclusions, which can greatly reduce the detection process, save a lot of manpower and material resources, reduce the test cost, and have stronger on-site adaptability.

In addition, before testing the pipeline, first use the adsorption test chamber to adsorb on a steel plate with a surface roughness of Ra3.2, size not less than the test chamber, and thickness not less than 5mm for adsorption test. The initial vacuum degree in the adsorption test chamber is P0 , within 20 to 60 minutes, the vacuum degree value in the adsorption test chamber is P1, and (P0-k×P1) is used as the qualified vacuum degree value, where k=1～5, and the K value is based on the roughness of the pipe surface to be measured. and the test conditions are determined. For example, when the roughness of the steel pipe surface is 0.8 to 1.6, K=1 is selected. When the roughness of the steel pipe is 1.6 to 3.2, K=3 is selected. When the roughness of the steel pipe is above 3.2, K=1 is selected. 5.

Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can make equivalent modifications or replacements without departing from the spirit of the present invention, and these equivalent modifications or replacements are included in the claims of the present application. within a limited range.

Claims (10)

1. an air tightness detection device of a pipeline, characterized in that: comprising: The adsorption test chamber is used to be adsorbed on the pipeline to be tested, the adsorption test chamber includes an adsorption device and a sealing cover, and the adsorption device is arranged at the opening of the sealing cover; a vacuum pump, communicated with the sealing cover through a first pipeline, and the first pipeline is provided with a first valve; The vacuum degree detection device is communicated with the first pipeline to detect the vacuum degree in the sealing cover. 2 . The air-tightness detection device of a pipeline according to claim 1 , wherein the adsorption device comprises a first suction cup and a second suction cup, and the first suction cup is located in the second suction cup and is connected with the The second suction cups are spaced apart from each other, the first suction cup and the second suction cup are spaced apart to define an adsorption chamber, the adsorption chamber is connected to the vacuum pump through a second pipeline, and a second valve is provided on the second pipeline . 3 . The air-tightness detection device of a pipeline according to claim 2 , wherein the first suction cup and the second suction cup are provided with rectangular compartment suction lips. 4 . 4 . The air-tightness detection device of a pipeline according to claim 1 , wherein the sealing cover is provided with a support frame for supporting the sealing cover. 5 . 5 . The air tightness detection device of a pipeline according to claim 2 , wherein the first suction cup and the second suction cup are provided with magnetic powder. 6 . 6 . The air tightness detection device of a pipeline according to claim 1 , wherein the vacuum degree detection device comprises a U-shaped tube, an air chamber and an air valve, and one end of the U-shaped tube is connected to the first tube. 7 . The other end of the U-shaped pipe is connected to the air chamber, and one side of the air chamber is provided with an air valve for opening and closing the air chamber. 7. A method for detecting air tightness of pipeline, characterized in that, comprising the following steps: Adsorb the adsorption test chamber on the pipeline to be tested; Start the vacuum pump and evacuate the adsorption test chamber to the initial vacuum value; turn off the vacuum system; By observing the corresponding readings of the vacuum detection device, the air tightness of the pipeline to be detected is judged. 8 . The method for detecting air tightness of a pipeline according to claim 7 , wherein before the adsorption test chamber is adsorbed on the pipeline to be detected, the area to be detected of the pipeline is processed until the roughness reaches Ra3.2 level. 9 . 9. The air tightness detection method of the pipeline according to claim 7, characterized in that: when observing the corresponding reading of the vacuum degree detection device, if the vacuum degree in the adsorption test chamber is not less than qualified within 20 to 60 minutes If the vacuum degree value is higher, the air tightness of the weld area of the pipeline to be tested meets the requirements. 10. The air tightness detection method of pipeline according to claim 9, it is characterized in that: before detecting pipeline, first adsorb the adsorption-type test chamber on a surface roughness Ra3.2 grade, the size is not smaller than the test chamber, the thickness is not The adsorption test is carried out on the steel plate less than 5mm. The initial vacuum degree in the adsorption test chamber is P0. Within 20 to 60 minutes, the vacuum degree in the adsorption test chamber is P1, and (P0-k×P1) is regarded as the qualified vacuum degree. value, where k=1～5, the k value is determined according to the roughness of the pipeline surface to be tested and the test conditions.

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