Water pressure test method for long-distance pipeline in mountain ridge water-deficient area

Abstract

The invention relates to a long-distance pipeline water pressure test method in a mountain ridge water-deficient area, which comprises the following steps of: 1, segmenting a pipeline, namely segmenting a water conveying pipeline, and totally dividing the whole water conveying pipeline into segments; secondly, a blocking plate is installed, the blocking plate is machined on site, a plurality of pieces of I-shaped steel are welded to the upper portion of the blocking plate, and the machined blocking plate and the pressure steel pipe are welded to install a circular seam; and step 3, injecting water and measuring pressure, injecting water into the welded pressure steel pipe, and performing a hydrostatic test on all pipelines of the project by adopting a mode of sequentially filling water section by section and pressing water section by section through measures of additionally arranging an external bypass pipe and a temporary pump station and the like, so that the problems of complex terrain, steep terrain, long water conveying pipeline, large fall, low working efficiency and the like of a construction site are smoothly solved. Meanwhile, the method is a one-time water filling and step-by-step cyclic utilization mode, and construction water is greatly saved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrostatic testing for long-distance pipelines, and particularly to a method for hydrostatic testing of long-distance pipelines in mountainous areas lacking water Background Technique

[0002] With the rapid development of the national economy, in order to make up for the short board of water conservancy infrastructure in plateau areas, at present, long-distance large and medium-diameter pipeline projects such as long-distance water diversion and regulation, river-lake connection, and interconnection between reservoirs are relatively common; however, when conducting hydrostatic testing of pipelines, due to the steep and complex terrain, long line, large elevation difference, and diverse ground environmental forms through which the pipeline passes in mountainous areas lacking water, and the surrounding areas of the pipeline are mostly water-deficient areas, it is difficult to obtain suitable test water and drain water. According to traditional methods, the investment cost will increase or the construction period will be longer. How to efficiently and quickly conduct hydrostatic testing of long-distance large and medium-diameter water conveyance pipelines in water-scarce plateau areas is a major problem in construction

[0003] In an existing method for hydrostatic testing of long-distance pipelines in the technical field of hydrostatic testing of long-distance pipelines in mountainous areas lacking water, there is no suitable water source point available for testing along the pipeline of the device, the conditions for using it as a transportation passage along the way are poor, and new roads need to be built in some positions to pass. The test water cannot be drained centrally, and water is filled and pressure tested section by section and then drained, which takes a long time and has a great impact on the construction period Summary of the Invention

[0004] The purpose of the present invention is to provide a method for hydrostatic testing of long-distance pipelines in mountainous areas lacking water, so as to solve the problems raised in the above background technique

[0005] To achieve the above purpose, the present invention provides the following technical solutions

[0006] A method for hydrostatic testing of long-distance pipelines in mountainous areas lacking water, characterized by including the following steps

[0007] Step 1. Pipeline segmentation, segment the water conveyance pipeline, and the entire water conveyance pipeline is divided into segments in total

[0008] Step 2. Installation of blind plates, process the blind plates on site, weld a plurality of I-beams above the blind plates, and weld the processed blind plates to the pressure steel pipe to install the circumferential weld

[0009] Step 3. Water injection and pressure measurement, inject water into the welded pressure steel pipe, conduct a non-leakage pressure test on the pressure steel pipe. When the internal pressure does not change, inject water into the next section of the pressure steel pipe through the connecting pipe. When the pressure does not meet the requirements, the pressure steel pipe needs to be repaired, and the repaired pressure steel pipe is re-injected with water and tested until it is qualified

[0010] Step 4. Pipeline drainage: After all the hydraulic pressure tests of the penstock are completed, the water inside is drained into the nearby water channel through the connecting pipe on the end penstock.

[0011] Step 5. Pipeline connection: After the water inside the penstock is drained, the blind plate is disassembled, and then the segmented penstock is restored and connected.

[0012] As a preferred solution of the present invention, in the above Step 1, the length of a single-section spiral steel pipe of the penstock is not greater than m. For the special paragraphs with large elevation differences, they are segmented and tested separately. The segmentation points are preferably selected at the "concave" points of the pipeline, and try to ensure that the first section of the steel pipe at the water pressure starting point is the longest section of the whole line.

[0013] As a preferred solution of the present invention, in the above Step 2, the blind plate is processed from a steel plate with a wall thickness of mm into a square of × mm. The I-beams on the penstock are arranged and welded in a "field" shape. After the blind plate is welded, # I-beams are arranged along the penstock, and the penstock and the blind plate are welded firmly.

[0014] As a preferred solution of the present invention, an exhaust valve, a pressure gauge, and a pressure pump are connected to the connecting pipe welded to the blind plate to conduct a hydraulic pressure test on the penstock. The blind plate is provided with a seamless pipe with a DN as the connecting pipe between the upper and lower test pipelines. A cut-off valve is connected in the middle of the connecting pipe by a flange. A drain valve is connected to the upper surface of the connecting pipe. The connecting pipe and the upper blind plate are connected by full welding, and the lower part is connected by spot welding to adapt to the expansion and deformation of the front pipeline after water filling. After the test of the front pipeline is completed, full welding is carried out.

[0015] As a preferred solution of the present invention, in the above Step 3, the water pump pumps water from the reservoir area river into the penstock. When the water overflows from the exhaust valve of this test section, close the exhaust valve and stop filling water into the penstock. After the test section of the penstock is filled with water, it needs to be fully soaked for hours under the condition of not greater than the working pressure before conducting the hydraulic pressure test.

[0016] As a preferred solution of the present invention, the water pressure inside the penstock is slowly raised to the test pressure and stabilized for min. During the pressure test process, the pressure is increased and decreased at a step difference of.MPa / level, and each level is stabilized for min. Check whether there are any water leakage, damage, etc. at the pipeline interfaces, fittings, etc. of the penstock; when there are water leakage and damage phenomena, the pressure test should be stopped in time, and at the same time, find out the reasons and conduct the pressure test again.

[0017] As a preferred solution of the present invention, after the pressure test of the penstock is completed, a detailed inspection is carried out on all the test pipelines of the penstock, the deformation of the pipeline and the anchor block is measured, and inspection records are made. If there is no abnormal situation, then the test pressure is reduced to the working pressure and kept constant for min, and an appearance inspection is carried out. If there is no water leakage phenomenon, the hydraulic pressure test is qualified.

[0018] As a preferred embodiment of the present invention, in step four, after the hydraulic test of the previous section of the penstock is completed and qualified, the drain valve on the upper and lower connecting pipes can be opened, and the water in the penstock is drained to the next test section by gravity or pressurization. If the water volume in the next test section is insufficient, water is pumped from the reservoir river into the penstock by a water pump and then drained to the test section to complete the water injection. After the hydraulic test of the penstock for the entire pipeline is completed, the connecting pipe and the blind plate are removed, and the penstock is repaired and welded, and the construction of the reserved pipe section is installed.

[0019] As a preferred embodiment of the present invention, blind plates are welded to both ends of each penstock. An I-beam welded and fixed to it is provided on the outer wall of each penstock near the blind plate. A plurality of I-beams in a cross shape are welded to the outer wall of each blind plate away from the penstock. A connecting pipe communicating with the penstock is connected to the lower side of the cross-shaped I-beam at the relative position of each blind plate. A drain valve is provided above one side of each connecting pipe, and a cut-off valve is provided in the middle of each connecting pipe. A connecting pipe communicating with the penstock is provided in the cross-shaped frame of the cross-shaped I-beam obliquely above the connecting pipe on the outer walls of the two blind plates. The top of each connecting pipe is connected to a pressure pump. An exhaust valve is provided on one side of each connecting pipe where the pressure pump is located. A pressure gauge is provided between each pressure pump and the exhaust valve. A water pump is provided on one side of one blind plate.

[0020] As a preferred embodiment of the present invention, each connecting pipe is hermetically connected to the blind plate, each cut-off valve is hermetically connected to the connecting pipe, each drain valve is hermetically connected to the connecting pipe, each connecting pipe is hermetically connected to the blind plate, each exhaust valve is hermetically connected to the connecting pipe, each pressure pump is hermetically connected to the connecting pipe, and each pressure gauge is hermetically connected to the connecting pipe.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: By adding measures such as an external bypass pipe and a temporary pumping station, the hydraulic test of all pipelines of this project is carried out in a way of filling water section by section in sequence and pressing water section by section, successfully solving the problems of complex terrain, steep terrain, long water transmission pipeline, large drop, and difficult and long-period pipeline hydraulic pressure under the condition of poor water sources along the pipeline at the construction site. At the same time, this method is a one-time water filling and step-by-step recycling method, which greatly saves construction water. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flow chart of the present invention;

[0023] Figure 2 is an isometric view of the overall structure of the present invention;

[0024] Figure 3 is a plan view of the overall structure of the present invention;

[0025] Figure 4Axonometric view of the plug plate and I-beam of the present invention;

[0026] Figure 5 Plan view of the plug plate and I-beam of the present invention.

[0027] In the figure: 1, penstock; 2, plug plate; 3, I-beam; 4, water pump; 5, connecting pipe; 6, exhaust valve; 7, pressure gauge; 8, booster pump; 9, communicating pipe; 10, drain valve; 11, shut-off valve. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0029] Next, the embodiments of the present invention will be described according to the overall structure of the present invention.

[0030] Embodiment

[0031] Embodiment, please refer to Figures 1-5 A method for hydrostatic test of long-distance pipelines in water-scarce mountainous areas, characterized by including the following steps:

[0032] Step 1: Pipeline segmentation. The water conveyance pipeline is segmented, and the entire water conveyance pipeline is divided into 30 segments in total;

[0033] Step 2: Plug plate installation. The plug plate 2 is processed on site, a plurality of I-beams 3 are welded above the plug plate 2, and the processed plug plate 2 is welded and installed with the circumferential weld of the penstock 1;

[0034] Step 3: Water injection and pressure measurement. Water is injected into the welded penstock 1, and a non-leakage pressure test is carried out on the penstock 1. When there is no change in the internal pressure, water is injected into the next section of the penstock 1 through the communicating pipe 9. When the pressure does not meet the requirements, the penstock 1 needs to be repaired, and the repaired penstock 1 is re-injected and tested until it is qualified;

[0035] Step 4: Pipeline drainage. When the hydrostatic test of the penstock 1 is all completed, the water inside is discharged to the nearest water channel through the communicating pipe 9 on the end penstock 1;

[0036] Step 5: Pipeline connection. After the water inside the penstock 1 is discharged, the plug plate 2 is disassembled, and then the segmented penstock 1 is restored and connected. In Step 1, the length of a single-section spiral steel pipe of the penstock 1 is not greater than 1000 m. For special sections with large elevation differences, they are segmented and tested separately. The segmentation points are preferably selected at the "concave" points of the pipeline, and try to ensure that the first section of the steel pipe at the starting point of the water pressure test is the longest section of the whole line.

[0037] In Step 2, the blocking plate 2 is processed from a steel plate with a wall thickness of 18 mm into a square of 1350×1350 mm. The I-beams 3 on the penstock 1 are arranged and welded in a grid pattern. After the blocking plate 2 is welded, 6 pieces of 14# I-beams 3 are arranged along the penstock 1, and the penstock 1 and the blocking plate 2 are firmly welded. An exhaust valve 6, a pressure gauge 7, and a pressure pump 8 are connected to the connecting pipe 5 welded to the blocking plate 2 to conduct a hydrostatic test on the penstock 1. The blocking plate 2 is provided with a seamless pipe of DN150 as a connecting pipe 9 between the upper and lower test pipelines. A cut-off valve 11 is connected in the middle of the connecting pipe 9 by a flange. A drain valve 10 is connected to the upper surface of the connecting pipe 9. The connecting pipe 9 is connected to the upper blocking plate 2 by full welding and to the lower one by spot welding to adapt to the expansion and deformation of the front pipeline after water filling. After the test of the front pipeline is completed, full welding is carried out. In Step 3, the water pump 4 pumps water from the reservoir river into the penstock 1. When water overflows from the exhaust valve 6 of this test section, close this exhaust valve 6 and stop filling water into the penstock 1. After the penstock 1 of the test section is filled with water, it needs to be fully soaked for 24 hours under the condition of not exceeding the working pressure before conducting the hydrostatic test. The water pressure in the penstock 1 slowly rises to the test pressure and is kept stable for 30 min. During the pressure test process, pressurization and depressurization are carried out at a step difference of 0.2 MPa / level, and each level is kept stable for 10 min. Check whether there are any phenomena such as water leakage and damage at the pipe joints, fittings, etc. of the penstock 1; when there are water leakage and damage phenomena, the pressure test should be stopped in time, and at the same time, find out the reasons and conduct the pressure test again. After the pressure test of the penstock 1 is completed, conduct a detailed inspection on all the test pipelines of the penstock 1, measure the deformation of the pipeline and the anchor block, and make inspection records. If there is no abnormal situation, then reduce the test pressure to the working pressure and keep the pressure constant for 30 min. Conduct an appearance inspection. If there is no water leakage, the hydrostatic test is qualified. In Step 4, when the hydrostatic test of the upper penstock 1 is completely completed and qualified, the drain valve 10 on the upper and lower connecting pipe 9 can be opened, and the water in the penstock 1 is drained to the next test section by gravity or pressurization. If the water volume in the next test section is insufficient, use the water pump 4 to pump water from the reservoir river into the penstock 1 and drain it to the test section to complete water injection. After the hydrostatic test of all the penstocks 1 of the whole pipeline section is completed, cut off the connecting pipe 9 and the blocking plate 2, repair and weld the penstock 1, and construct the installation of the reserved pipe section.

[0038] By means of measures such as adding an external bypass pipe and a temporary pumping station, the hydrostatic test was carried out on all the pipelines of this project in the way of filling water section by section in sequence and pressing water section by section, successfully solving the problems of complex terrain, steep topography, long water conveyance pipeline, large elevation difference at the construction site, and difficult and time-consuming pipeline hydrostatic pressure under the condition of poor water sources along the pipeline. At the same time, this method is a one-time water filling and step-by-step recycling method, which greatly saves construction water.

[0039] Please refer to Figures 2-5, blind plates 2 are welded to both ends of the penstock 1. I-beams 3 are welded and fixed to the outer wall of the penstock 1 near the blind plates 2. A plurality of I-beams 3 in a cross shape are welded to the outer wall of the blind plate 2 away from the penstock 1. A communicating pipe 9 communicating with the penstock 1 is connected to the lower side of the I-beams 3 in a cross shape at the relative position of the blind plate 2. Drain valves 10 are provided above one side of the communicating pipe 9. A cut-off valve 11 is provided in the middle of the communicating pipe 9. A connecting pipe 5 communicating with the penstock 1 is provided in the cross frame of the I-beams 3 in a cross shape on the outer wall of the blind plate 2 diagonally above the communicating pipe 9. The top of the connecting pipe 5 is connected to a pressure pump 8. An exhaust valve 6 is provided on one side of the connecting pipe 5 where the pressure pump 8 is located. A pressure gauge 7 is provided between the pressure pump 8 and the exhaust valve 6. A water pump 4 is provided on one side of one blind plate 2. The communicating pipe 9 is hermetically connected to the blind plate 2. The cut-off valve 11 is hermetically connected to the communicating pipe 9. The drain valve 10 is hermetically connected to the communicating pipe 9. The connecting pipe 5 is hermetically connected to the blind plate 2. The exhaust valve 6 is hermetically connected to the connecting pipe 5. The pressure pump 8 is hermetically connected to the connecting pipe 5. The pressure gauge 7 is hermetically connected to the connecting pipe 5.

[0040] The staff starts the water pump 4 through an external controller to pump the water in the water channel into the penstock 1. When the water in the penstock 1 overflows from the exhaust valve 6 through the connecting pipe 5, the staff stops the water pump 4. Then, the pressure in the penstock 1 is increased through the pressure pump 8, and the pressure inside the penstock 1 is observed through the pressure gauge 7. When the hydraulic pressure test of this section of the penstock 1 is qualified, the staff opens the cut-off valve 11 through the external controller, and the water in this section of the penstock 1 is conveyed to the next section of the penstock 1 through the communicating pipe 9. After the conveyance is completed, the above operation is repeated to conduct the hydraulic pressure test inside the penstock 1. When the hydraulic pressure tests of all penstocks 1 are qualified, the staff discharges the water flow inside the penstock 1 through the drain valve 10 on the last section of the penstock 1. When the water in a local penstock 1 needs to be discharged, the internal water is led out to the nearest water channel through the drain valve 10 on the communicating pipe 9 for discharge.

[0041] Workflow of the present invention: When performing a long-distance water pressure test on a pipeline, the staff starts the water pump 4 through an external controller to pump water from the water channel into the penstock 1. When the water in the penstock 1 overflows from the exhaust valve 6 through the connecting pipe 5, the staff stops the water pump 4. Then, the pressure in the penstock 1 is increased by the pressure pump 8, and the pressure inside the penstock 1 is observed through the pressure gauge 7. When the water pressure test of this section of the penstock 1 is qualified, the staff opens the cut-off valve 11 through the external controller, and the water in this section of the penstock 1 is conveyed to the next section of the penstock 1 through the connecting pipe 9. After the conveyance is completed, the above operations are repeated to perform a water pressure test on the penstock 1. After the water pressure tests of all penstocks 1 are qualified, the staff discharges the water in the penstock 1 through the drain valve 10 on the last section of the penstock 1. When the water in a local penstock 1 needs to be discharged, the internal water is led out to the nearest water channel through the drain valve 10 on the connecting pipe 9 for discharge. After all the water in the penstocks 1 is discharged, the staff removes the blind plate 2 on all the penstocks 1, and then performs welding treatment on the penstocks 1.

[0042] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for hydrostatic test of long-distance pipelines in water-scarce mountainous areas, characterized in that, It includes the following steps: Step 1: Pipeline segmentation. The water conveyance pipeline is segmented, and the entire water conveyance pipeline is divided into 30 segments in total. Step 2: Blind plate installation. The blind plate (2) is processed on-site. A plurality of I-beams (3) are welded above the blind plate (2). The processed blind plate (2) is welded to the penstock (1) to install the circumferential weld. Step 3: Water injection and pressure measurement. Water is injected into the welded penstock (1), and non-leakage pressure detection is carried out on the penstock (1). When the internal pressure remains unchanged, water is injected into the next section of the penstock (1) through the connecting pipe (9). When the pressure does not meet the requirements, the penstock (1) needs to be repaired, and the repaired penstock (1) is re-injected with water for testing until it is qualified. Step 4: Pipeline drainage. When the water pressure test of the penstock (1) is all completed, the water inside is discharged to the nearby water channel through the connecting pipe (9) on the end penstock (1). Step 5: Pipeline connection. After the water inside the penstock (1) is discharged, the blind plate (2) is disassembled, and then the segmented penstocks (1) are restored and connected.

2. A method for hydrostatic testing of long-distance pipelines in water-scarce mountainous areas according to claim 1, characterized in that: In the said Step 1, the length of a single-section spiral steel pipe of the penstock (1) is not greater than 1000 m. The special sections with large elevation differences are segmented and pressure-tested separately. The segmentation points are preferably selected at the "concave" points of the pipeline, and try to ensure that the first section of the steel pipe at the water pressure starting point is the longest section of the whole line.

3. A method for hydrostatic testing of a long-distance pipeline in a water-scarce mountainous area according to claim 1, characterized in that: In the said Step 2, the blind plate (2) is processed from a steel plate with a wall thickness of 18 mm into a square with a size of 1350×1350 mm. The I-beams (3) on the penstock (1) are arranged and welded in a "field" shape. After the blind plate (2) is welded, 6 14# I-beams (3) are arranged along the penstock (1), and the penstock (1) and the blind plate (2) are welded firmly.

4. A method for hydrostatic test of long-distance pipelines in water-scarce mountainous areas according to claim 3, characterized in that: An exhaust valve (6), a pressure gauge (7), and a pressure pump (8) are connected to the connecting pipe (5) welded to the blind plate (2) to carry out the water pressure test inside the penstock (1). The blind plate (2) is provided with a seamless pipe with a DN150 as the connecting pipe (9) between the upper and lower section pressure test pipes. A cut-off valve (11) is connected in the middle of the connecting pipe (9) by a flange. A drain valve (10) is connected to the upper surface of the connecting pipe (9). The connecting pipe (9) is connected to the upper blind plate (2) by a full weld and to the lower one by a spot weld to adapt to the expansion and deformation of the front section of the pipeline after water filling. After the test of the front section of the pipeline is completed, full welding is carried out.

5. A method for hydrostatic testing of long-distance pipelines in water-scarce mountainous areas according to claim 1, characterized in that: In the said Step 3, the water pump (4) pumps water from the reservoir area river channel into the penstock (1). When water overflows from the exhaust valve (6) of this test section, close the exhaust valve (6) and stop filling water into the penstock (1). After the test section of the penstock (1) is filled with water, it needs to be fully soaked for 24 hours under the condition of not greater than the working pressure before carrying out the water pressure test.

6. A method for hydrostatic testing of long-distance pipelines in water-scarce mountainous areas according to claim 5, characterized in that: The water pressure inside the penstock (1) is slowly raised to the test pressure and kept stable for 30 min. During the pressure test process, the pressure is increased and decreased at a step difference of 0.2 MPa / level, and each level is kept stable for 10 min. Check whether there are any phenomena such as water leakage and damage at the pipeline interfaces, fittings, etc. of the penstock (1); when there are phenomena of water leakage and damage, the pressure test should be stopped in time, and at the same time, find out the reasons and re-conduct the pressure test.

7. A method for hydrostatic testing of long-distance pipelines in water-scarce mountainous areas according to claim 1, characterized in that: After the pressure test of the penstock (1) is completed, conduct a detailed inspection of the test pipelines of all penstocks (1), measure the deformation of the pipelines and the anchor blocks, and make inspection records. If there are no abnormalities, then reduce the test pressure to the working pressure and maintain a constant pressure for 30 minutes. Conduct an appearance inspection. If there is no water leakage, the hydrostatic test is qualified.

8. A method for hydrostatic testing of long-distance pipelines in water-scarce mountainous areas according to claim 1, characterized in that: In the fourth step, when the hydrostatic test of the previous section of the penstock (1) is completely finished and qualified, the drain valve (10) on the upper and lower connecting pipes (9) can be opened, and the water in the penstock (1) is drained to the next test section by gravity or pressurization. If the water volume in the next test section is insufficient, use a water pump (4) to pump water from the reservoir river channel into the penstock (1) and drain it to the test section to complete the water injection. After the hydrostatic test of all penstocks (1) in the entire pipeline section is completed, remove the connecting pipe (9) and the blind plate (2), repair and weld the penstock (1), and install the reserved pipe section for construction.

9. A method for hydrostatic test of long-distance pipelines in water-scarce mountainous areas according to claim 1, characterized in that: Blind plates (2) are welded to both ends of each penstock (1). An I-beam (3) welded and fixed to it is provided on the outer wall of each penstock (1) near the blind plate (2). On the outer wall of each blind plate (2) away from the penstock (1), a plurality of I-beams (3) in a cross shape are welded. On the lower side of the cross-shaped I-beams (3) where each pair of blind plates (2) is located, a connecting pipe (9) communicating with the penstock (1) is connected. A drain valve (10) is provided above one side of each connecting pipe (9). A cut-off valve (11) is provided in the middle of each connecting pipe (9). In the cross-shaped frame of the cross-shaped I-beams (3) on the outer wall of the two blind plates (2) obliquely above the connecting pipe (9), a connecting pipe (5) communicating with the penstock (1) is provided. A pressure pump (8) is connected to the top of each connecting pipe (5). An exhaust valve (6) is provided on one side of each connecting pipe (5) where the pressure pump (8) is located. A pressure gauge (7) is provided between each pressure pump (8) and the exhaust valve (6). A water pump (4) is provided on one side of one blind plate (2).

10. A method for hydraulic pressure test of long-distance pipelines in water-scarce mountainous areas according to claim 9, characterized in that: Each connecting pipe (9) is hermetically connected to the blind plate (2), each cut-off valve (11) is hermetically connected to the connecting pipe (9), each drain valve (10) is hermetically connected to the connecting pipe (9), each connecting pipe (5) is hermetically connected to the blind plate (2), each exhaust valve (6) is hermetically connected to the connecting pipe (5), each pressure pump (8) is hermetically connected to the connecting pipe (5), and each pressure gauge (7) is hermetically connected to the connecting pipe (5).

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