Dual air supply pipe prevents debris, rust and dust blowing into the withdrawal of the blocking vent method of clamp valve

Abstract

The application discloses a method for preventing iron filings, rust and dust from being blown into a clamp valve by using a double-gas-source pipeline, and belongs to the technical field of pipeline maintenance. The method comprises a primary pressure gas source pipeline and a pressure-reducing gas source pipeline, a high-pressure side plugging device arranged on the primary pressure gas source pipeline, and a low-pressure side plugging device arranged on the pressure-reducing gas source pipeline. The pressure of the pressure-reducing gas source pipeline is less than the pressure of the primary pressure gas source pipeline by more than 0.1 Mpa. The first plugging expansion cylinder of the high-pressure side plugging device has an open front face facing the primary pressure gas source pipeline. The second plugging expansion cylinder of the low-pressure side plugging device has an open front face facing the pressure-reducing gas source pipeline. The plugging removal and ventilation process is as follows: 1. removing the low-pressure side plugging device to connect the pressure-reducing gas source pipeline and a new pipeline; 2. after gas in the pressure-reducing gas source pipeline enters the new pipeline and the pressure remains unchanged, the high-pressure side plugging device is removed; and 3. the plugging removal is completed, and the pipeline is ventilated. The application can more simply and effectively prevent iron filings, rust and dust from entering the clamp valve, does not increase the cost, and can be applied to the maintenance of various gas conveying pipelines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas pipeline repair, in particular to a method for preventing debris, rust and dust from being blown into a clamp valve during the removal of a blockage and ventilation of a pipeline with double gas sources. BACKGROUND

[0002] In the plugging process, the stoppage double-side single-plugging process is composed of two stoppage single-side single-plugging processes.

[0003] As shown in FIGS. Figure 1 and Figure 2 In the existing plugging construction, the expansion cylinder is placed in the plugging part, the opening of the expansion cylinder faces the gas source, the expansion cylinder is expanded by rotating the plugging device operating rod, the rubber skin layer on the surface of the expansion cylinder is fully in contact with the end face of the broken pipe, and the plugging is completed.

[0004] In addition, as a cylinder, the opening side of the expansion cylinder is generally referred to as the front face of the expansion cylinder, and the other side opposite to the opening side is referred to as the back face of the expansion cylinder.

[0005] In the stoppage single-side single-plugging construction, the following two situations may occur during the removal of the plugging:

[0006] Firstly, the opening of the expansion cylinder is aligned with the incoming gas direction, that is, the pipeline pressure on the opening side of the expansion cylinder is greater than the pipeline pressure on the back side, the gas flow direction at the contact position between the end face of the broken pipe and the expansion cylinder is along the surface of the expansion cylinder from the front face to the back face, and the gas flow is collected into the working pipeline through the end face of the broken pipe.

[0007] Since the pressure difference balance time on both sides of the back face of the expansion cylinder is short, and the gas flow is flowing from the back face of the expansion cylinder to the working pipeline during the pressure difference balance, when the expansion cylinder is loosened, it is generally not easy to form the accumulation of iron filings, rust and dust in the cavity of the clamp valve.

[0008] Secondly, the back face of the expansion cylinder is aligned with the incoming gas direction, that is, the pipeline pressure on the back side of the expansion cylinder is greater than the pipeline pressure on the opening side, the gas flow direction at the contact position between the end face of the broken pipe and the expansion cylinder is diffused along the back face of the expansion cylinder to the surrounding, the clamp valve, the plugging header and the low-pressure gas source pipeline, and therefore, when the expansion cylinder is loosened, it is easy to form the accumulation of iron filings, rust and dust in the cavity of the clamp valve.

[0009] Generally, for the reconstruction of the gas pipeline with double gas sources, the stoppage double-side single-plugging construction process is used to reconstruct the pipeline between the two plugging parts, after the pipeline is plugged, subsequent diffusion, pipe breaking, inlaying, replacement and other work are performed, and then the plugging is removed to restore the pipeline ventilation operation, and there is no special requirement for the sequence of removing the two plugging devices during the removal of the plugging.

[0010] However, when the pressure on one side of the two sides of the plugging is more than 0.1 Mpa lower than the pressure on the other side of the pipeline due to the user gas consumption and the owner pressure reduction during the plugging, the situation is completely different.

[0011] When the unblocking is performed in the presence of a pressure difference of 0.1 Mpa or more, the pressure of the gas source pipe on the two sides of the blocking can be known according to two external pressure gauges on the two blocking headers.

[0012] If the high-pressure side pipe expansion cylinder is loosened first, the first condition in the above-mentioned stoppage unblocking process of a single side and a single blockage will occur, the pipe pressure on the opening side of the expansion cylinder is greater than the pipe pressure on the back of the expansion cylinder, and generally the iron filings will not be blown into the clamp plate valve cavity when the expansion cylinder is loosened;

[0013] However, when the low-pressure side pipe expansion cylinder is loosened again, the second condition in the above-mentioned stoppage unblocking process of a single side and a single blockage will occur, the pipe pressure on the back of the expansion cylinder is greater than the pipe pressure on the opening side, and in the process of gas flowing from the high-pressure side to the low-pressure side, the iron filings, rust and dust in the pipe are easily brought into the clamp plate valve cavity, and the iron filings, rust and dust are accumulated in the clamp plate valve cavity.

[0014] In addition, in actual construction, the pressure difference balance time of the high-pressure side gas pressure to the low-pressure side is relatively long, and the long-time high-speed flow of gas will form a large amount of iron filings, dust and rust in the clamp plate valve cavity, which causes the clamp plate valve to be unable to be effectively closed when it is removed, and affects the sealing performance of the equipment and other adverse consequences.

[0015] Therefore, how to prevent the iron filings from being blown into the clamp plate valve cavity in the unblocking and ventilation method after the double-direction gas source pipe is blocked on both sides after stoppage, so as to cause the valve to be unable to be closed or even to be ineffective in opening and closing, and to ensure the safety of construction become technical problems to be solved by the technical personnel in the field. SUMMARY

[0016] In view of the above-mentioned defects of the prior art, the unblocking and ventilation method for preventing the iron filings, rust and dust from being blown into the clamp plate valve of the double gas source pipe is provided, and the purpose is achieved by detecting the running pressure of the gas in the pipe through the pressure gauge on the blocking equipment, according to the pressure balance principle of the upper and lower valve plates of the clamp plate valve, and preventing the iron filings, rust and dust from being blown into the cavity of the clamp plate valve in the unblocking and ventilation method after the double-direction gas source pipe is blocked on both sides after stoppage, so as to cause the valve to be unable to be closed or even to be ineffective in opening and closing, and to ensure the safety of construction.

[0017] In order to achieve the above-mentioned purpose, the unblocking and ventilation method for preventing the iron filings, rust and dust from being blown into the clamp plate valve of the double gas source pipe is disclosed, which comprises an original pressure gas source pipe and a pressure reducing gas source pipe connected with a new pipe after completion of replacement or maintenance, a high-pressure side blockage device arranged on the original pressure gas source pipe, and a low-pressure side blockage device arranged on the pressure reducing gas source pipe.

[0018] The pressure of the pressure reducing gas source pipe is less than the pressure of the original pressure gas source pipe by 0.1 Mpa or more;

[0019] The first sealing expansion cylinder of the high-pressure side plugger has an opening facing the original pressure gas source pipe;

[0020] The second sealing expansion cylinder of the low-pressure side plug has an opening facing the pressure-reducing gas source pipe;

[0021] The unblocking and ventilation process includes the following steps:

[0022] Step 1: Remove the low-pressure side plug and connect the pressure-reducing gas source pipe to the new pipe;

[0023] Step 2: After the gas enters the new pipeline from the pressure-reducing gas source pipe and the pressure no longer changes, remove the high-pressure side plug.

[0024] Step 3: After the sealing work is completed and the blockage is removed, the pipeline is ventilated.

[0025] Preferably, the pressure of the original compressed air source pipe is 0.4 MPa.

[0026] Preferably, the process of removing the low-pressure side plug in step 1 is as follows:

[0027] Step 1.1: Observe the pressure of the pressure-reducing gas source pipe through the second pressure gauge connected to the low-pressure side plug;

[0028] Step 1.2: Shrink the second sealing expansion cylinder;

[0029] Step 1.3: Lift the retracted second sealing expansion cylinder into the sealing manifold of the low-pressure side sealing device, and close the second clamp valve of the low-pressure side sealing device;

[0030] Step 1.4: Remove the second pressure gauge and open the second external valve of the low-pressure side plug to discharge the gas in the plugging manifold of the low-pressure side plug;

[0031] Step 1.5: After the gas in the sealing manifold of the low-pressure side plug is purged and the pressure drops to atmospheric pressure, the low-pressure side plugging equipment is removed in sequence, including the low-pressure side plug, the lower plug, the second clamp valve and the blind flange, to complete the removal of the low-pressure side plugging equipment.

[0032] Preferably, the process of removing the high-voltage side plug in step 2 is as follows:

[0033] Step 2.1: Shrink the first sealing expansion cylinder;

[0034] Step 2.2: Lift the first sealing expansion cylinder, which has completed shrinkage, into the sealing manifold of the high-pressure side sealing device, and close the first clamp valve of the high-pressure side sealing device;

[0035] Step 2.3, remove the first pressure gauge, and open the first pair of outer valves of the high-pressure side blockage device to discharge the gas in the blockage header of the high-pressure side blockage device;

[0036] Step 2.4, after the gas in the blockage header of the high-pressure side blockage device is discharged and the pressure is reduced to atmospheric pressure, sequentially remove the high-pressure side blockage device, including the high-pressure side blockage device, the lower plug, the first clamping plate valve and the blind plate, to complete the removal of the high-pressure side blockage device.

[0037] Advantages of the present application:

[0038] The application of the present application can more simply and effectively prevent iron filings, rust and dust from entering the clamping plate valve without increasing the cost, and can be applied to the maintenance of various gas conveying pipelines.

[0039] The concept, specific structure and technical effects of the present application will be further described below with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A structural schematic diagram showing the structure of a single blockage expansion cylinder in an unopened state in the prior art.

[0041] Figure 2 A structural schematic diagram showing the structure of a single blockage expansion cylinder in an opened state in the prior art.

[0042] Figure 3 An execution flowchart of an embodiment of the present application.

[0043] Figure 4 A structural schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0044] EMBODIMENT

[0045] As shown in Figure 3 and Figure 4 , the double-gas-source pipeline blockage removal and ventilation method for preventing filings, rust and dust from being blown into the clamping plate valve includes an original high-pressure gas source pipe 2 connected with a new pipeline 1 after replacement or maintenance is completed, a pressure-reducing gas source pipe 3, a high-pressure side blockage device 4 arranged in the original high-pressure gas source pipe 2, and a low-pressure side blockage device 5 arranged in the pressure-reducing gas source pipe 3.

[0046] The construction overview is as follows:

[0047] The size of the mother pipe is DN500;

[0048] The material of the mother pipe is Q235 seamless steel pipe;

[0049] The gas source direction is bidirectional gas source;

[0050] Original pressure source pipe 2 operating pressure: 0.4 MPa;

[0051] Pipeline design pressure: 1.6 MPa;

[0052] Blocking method: the opening of the expansion cylinder is expanded and blocked towards the gas source direction, as shown in Figure 1 and Figure 2 .

[0053] First, install blocking parts on both sides of the pipeline that needs to be modified, and complete the modification of the pipeline through steps such as welding, opening, blocking, diffusion, pipe cutting and splicing, and replacement.

[0054] The blocking part is commonly known as a split four-way;

[0055] The blocking header is also known as a blocking adapter, and the expansion cylinder is also known as a cylinder blocking head.

[0056] Unlike traditional processes, the improved blocking and venting method process steps are as follows:

[0057] On-site situation: During the diffusion, pipe cutting and splicing process, the operating pressure of the original pressure source pipe 2 and the reduced pressure source pipe 3 can be observed through the second pressure gauge 9 and the first pressure gauge 8.

[0058] The reduced pressure source pipe 3 is caused by user use, owner pressure reduction, etc., resulting in a decrease in pipeline pressure to 0.3 MPa.

[0059] The pressure of the reduced pressure source pipe 3 is less than 0.1 MPa than the pressure of the original pressure source pipe 2;

[0060] The first blocking expansion cylinder 6 of the high-pressure side blocking device 4 has an opening with the front facing the original pressure source pipe 2;

[0061] The second blocking expansion cylinder 7 of the low-pressure side blocking device 5 has an opening with the front facing the reduced pressure source pipe 3;

[0062] The blocking and venting process includes the following steps:

[0063] Step 1, remove the low-pressure side blocking device 5 to connect the reduced pressure source pipe 3 and the new pipeline 1;

[0064] Step 2, after the gas in the reduced pressure source pipe 3 enters the new pipeline 1 and the pressure does not change, remove the high-pressure side blocking device 4;

[0065] Step 3, the blocking construction is removed, and the pipeline venting is completed.

[0066] In actual application, because the gas in the reduced pressure source pipe 3 is under pressure, the pressure is greater than that of the new pipeline 1 without pressure, so iron filings, rust and dust will not enter the blocking header of the low-pressure side blocking device 5, but will be blown into the new pipeline 1.

[0067] When the gas enters the new pipeline 1, the iron filings, rust and dust enter the new pipeline 1 due to the pressure difference, and the first blocking expansion cylinder 6 is retracted. The pressure of the blocking joint box of the high-pressure side blocking device 4 is the same as the pressure of the original pressure gas source pipe 2, which is greater than the pressure 0.3 MPa of the pressure reduction gas source pipe 3 connected with the new pipeline 1 at this time, so the iron filings, rust and dust cannot enter the blocking joint box of the high-pressure side blocking device 4, but are blown into the new pipeline 1;

[0068] The above method effectively avoids the iron filings, rust and dust from entering the cavity of the first clamping plate valve 11 and the second clamping plate valve 10.

[0069] In some embodiments, the pressure of the original pressure gas source pipe 2 is 0.4 MPa.

[0070] In some embodiments, the process of removing the low-pressure side blocking device 5 in step 1 is as follows:

[0071] Step 1.1, observe the pressure of the pressure reduction gas source pipe 3 through the second pressure gauge 9 connected to the low-pressure side blocking device 5;

[0072] Step 1.2, retract the second blocking expansion cylinder 7;

[0073] Step 1.3, lift the retracted second blocking expansion cylinder 7 into the blocking joint box of the low-pressure side blocking device 5, and close the second clamping plate valve 10 of the low-pressure side blocking device 5;

[0074] Step 1.4, remove the second pressure gauge 9, and open the second external valve 12 of the low-pressure side blocking device 5 to discharge the gas in the blocking joint box of the low-pressure side blocking device 5;

[0075] Step 1.5, after the gas in the blocking joint box of the low-pressure side blocking device 5 is exhausted and the pressure is reduced to atmospheric pressure, sequentially remove the low-pressure side blocking equipment, including the low-pressure side blocking device 5, the lower plug, the second clamping plate valve 10 and the blind plate, to complete the removal of the low-pressure side blocking equipment.

[0076] In some embodiments, the process of removing the high-pressure side blocking device 4 in step 2 is as follows:

[0077] Step 2.1, retract the first blocking expansion cylinder 6;

[0078] Step 2.2, lift the retracted first blocking expansion cylinder 6 into the blocking joint box of the high-pressure side blocking device 4, and close the first clamping plate valve 11 of the high-pressure side blocking device 4;

[0079] Step 2.3, remove the first pressure gauge 8, and open the first external valve 13 of the high-pressure side blocking device 4 to discharge the gas in the blocking joint box of the high-pressure side blocking device 4;

[0080] Step 2.4, after the gas in the sealing header of the high-pressure side sealing device 4 is exhausted and the pressure is reduced to atmospheric pressure, the high-pressure side sealing device is removed in sequence, including the high-pressure side sealing device 4, the lower plug, the first clamping plate valve 11 and the blind plate, and the removal of the high-pressure side sealing device is completed.

[0081] The preferred embodiments of the application are described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations without departing from the concept of the application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the prior art according to the concept of the application should be within the protection scope defined by the claims.

Claims

1. A method for preventing debris, rust and dust from being blown into a clamp valve during the removal of a blockage in a pipeline, comprising an original high-pressure gas source pipe (2) and a reduced-pressure gas source pipe (3) connected to a new pipeline (1) after completion of replacement or maintenance, and a high-pressure side blockage device (4) provided in the original high-pressure gas source pipe (2) and a low-pressure side blockage device (5) provided in the reduced-pressure gas source pipe (3); characterized in that: the pressure of the reduced-pressure gas source pipe (3) is less than the pressure of the original high-pressure gas source pipe (2) by more than 0.1 Mpa; the first blockage expansion cylinder (6) of the high-pressure side blockage device (4) has an open front face facing the original high-pressure gas source pipe (2); the second blockage expansion cylinder (7) of the low-pressure side blockage device (5) has an open front face facing the reduced-pressure gas source pipe (3); the process of removing the blockage and ventilating the pipeline comprises the following steps: Step 1: remove the low-pressure side blockage device (5) to connect the reduced-pressure gas source pipe (3) to the new pipeline (1); Step 2: after the gas in the reduced-pressure gas source pipe (3) enters the new pipeline (1) and the pressure remains unchanged, remove the high-pressure side blockage device (4); Step 3: blockage removal is completed, and the pipeline is ventilated. The pressure of the original high-pressure gas source pipe (2) is 0.4 Mpa. The process of removing the low-pressure side blockage device (5) in Step 1 is as follows: Step 1.1: observe the pressure of the reduced-pressure gas source pipe (3) through the second pressure gauge (9) connected to the low-pressure side blockage device (5); Step 1.2: shrink the second blockage expansion cylinder (7); Step 1.3: lift the shrunk second blockage expansion cylinder (7) into the blockage joint box of the low-pressure side blockage device (5) and close the second clamp valve (10) of the low-pressure side blockage device (5); Step 1.4: remove the second pressure gauge (9) and open the second external valve (12) of the low-pressure side blockage device (5) to discharge the gas in the blockage joint box of the low-pressure side blockage device (5); Step 1.5: after the gas in the blockage joint box of the low-pressure side blockage device (5) is discharged and the pressure drops to atmospheric pressure, sequentially remove the low-pressure side blockage device, including the low-pressure side blockage device (5), the lower plug, the second clamp valve (10) and the blind plate, to complete the removal of the low-pressure side blockage device. The process of removing the high-pressure side blockage device (4) in Step 2 is as follows: Step 2.1: shrink the first blockage expansion cylinder (6); Step 2.2: lift the shrunk first blockage expansion cylinder (6) into the blockage joint box of the high-pressure side blockage device (4) and close the first clamp valve (11) of the high-pressure side blockage device (4); Step 2.3: remove the first pressure gauge (8) of the high-pressure side blockage device (4) and open the first external valve (13) of the high-pressure side blockage device (4) to discharge the gas in the blockage joint box of the high-pressure side blockage device (4). ​ ​ ​ ​ 2. The dual air supply method of claim 1, wherein, ​ 3. The dual air supply method of claim 1, wherein the method further comprises: ​ ​ ​ ​ ​ ​ 4. The dual air supply method of claim 1, wherein the method further comprises: ​ ​ ​ ​ Step 2.4, after the gas in the plugging header of the high-pressure side plugging device (4) is exhausted and the pressure is reduced to atmospheric pressure, the high-pressure side plugging device is removed in sequence, specifically including the high-pressure side plugging device (4), the lower plug, the first clamping plate valve (11) and the blind plate, and the removal of the high-pressure side plugging device is completed.

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