Pressure testing method for multiple sealing pipe joints

Abstract

The invention discloses a pressure testing method for multiple sealing pipe joints, and belongs to the technical field of pipeline construction, and the method comprises the steps: S1, forming a connecting through hole in the outer wall of a first pipe joint, and enabling the connecting through hole to communicate a sealing cavity with the outside; s2, the first pipe joint and the second pipe joint are in coaxial butt joint to form a to-be-tested pipe system; s3, the sealing cavity is filled with test liquid through the connecting through hole; s4, continuously pressurizing the sealing cavity through the connecting through hole, and measuring a test pressure value in the sealing cavity in real time; and S5, obtaining the pressure condition of the to-be-tested pipe system based on the leakage condition of the test liquid and the test pressure value. According to the testing method, under the condition that the to-be-tested pipe system body does not need to be greatly damaged, pressure testing can be effectively conducted on the multiple sealing pipe joints, the cost is low, and the measuring efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline construction, and particularly relates to a pressure testing method for multi-channel sealed pipe joints. Background Art

[0002] Pipe jacking construction, as a trenchless or less-excavation pipeline laying construction technology, is applicable to projects that need to cross complex sections such as railways, highways, rivers or buildings. Concrete pipes are widely used in pipe jacking construction due to their outstanding characteristics such as high strength, good durability and corrosion resistance.

[0003] For pipe jacking construction, the sealing performance of concrete pipes not only concerns the construction quality and service life of the pipeline, but also directly affects the safety of pipe jacking construction and the stability of subsequent pipeline operation. Especially in scenarios such as underwater crossing and construction in loose strata, the importance of sealing is more prominent. Concrete pipes are generally divided into two forms: single-channel sealed concrete pipes and multi-channel sealed concrete pipes. There is only one seal inside a single-channel sealed concrete pipe, and multiple seals are arranged along the axial direction of the pipe inside a multi-channel sealed concrete pipe.

[0004] In order to evaluate the sealing performance of concrete pipes in pipe jacking construction, it is necessary to test the sealing pressure of the pipeline. However, in the existing technologies at home and abroad, there is only an internal pressure testing method for the sealing of concrete pipe joints. It is mainly to inject liquid or gas into the concrete pipe, gradually increase the internal pressure by using a pressure device, and use equipment such as pressure sensors to monitor the internal pressure value of the concrete pipe in real time. During the pressurization process, observe whether there is any leakage at the sealing part of the concrete pipe, and record the pressure value when leakage first occurs, so as to evaluate the performance of the concrete pipe seal under the action of internal pressure. This testing method can simulate the situation where the concrete pipe bears internal fluid pressure during actual use.

[0005] However, the above method only focuses on the testing process of the internal pressure of concrete pipes. There is currently no external pressure testing method for concrete pipes. However, in actual construction, the external pressure conditions faced by concrete pipes are complex. The external pressure from rock masses and soil may cause lateral displacement, compression deformation or even local damage of the seals, and the existing internal pressure testing cannot simulate such failure modes.

[0006] Therefore, there is an urgent need for a pressure testing method for multi-channel sealed pipe joints that can effectively test both the internal and external pressures of the multi-channel sealed pipe joints of concrete pipes to meet the sealing performance evaluation of concrete pipes. Summary of the Invention

[0007] The purpose of the present invention is to provide a pressure testing method for multi-channel sealed pipe joints to solve the technical problem in the existing technology that there is a lack of effective testing for both the internal and external pressures of multi-channel sealed pipe joints.

[0008] As described above in the concept, the technical solution adopted by the present invention is as follows:

[0009] A pressure test method for multi-channel sealed pipe joints, applied to a pipe system to be tested. The pipe system to be tested includes a first pipe joint and a second pipe joint. Two seals are arranged at intervals along the axial direction of the inner wall of the first pipe joint, and a sealed cavity is formed between the two seals. The pressure test method for multi-channel sealed pipe joints includes:

[0010] S1. Open a connection through-hole on the outer wall of the first pipe joint for communicating the sealed cavity with the outside;

[0011] S2. Docking the first pipe joint and the second pipe joint coaxially to form the pipe system to be tested;

[0012] S3. Fill the sealed cavity with a test liquid through the connection through-hole;

[0013] S4. Continuously pressurize the sealed cavity through the connection through-hole and measure the test pressure value in the sealed cavity in real time;

[0014] S5. Obtain the pressure condition of the pipe system to be tested based on the leakage condition of the test liquid and the test pressure value.

[0015] Preferably, in S5, when the test liquid leaks from the inside of the pipe system to be tested, record the test pressure value at this moment, and substitute the test pressure value into a first preset formula to obtain the external pressure value of the pipe system to be tested.

[0016] Preferably, when the leakage position is at the bottom of the pipe system to be tested, the first preset formula is:

[0017]

[0018] When the leakage position is in the middle of the pipe system to be tested, the first preset formula is:

[0019]

[0020] When the leakage position is at the top of the pipe system to be tested, the first preset formula is:

[0021] P1 = P2

[0022] Wherein, P1 is the external pressure value, P2 is the test pressure value, and D1 is the outer diameter of the pipe system to be tested.

[0023] Preferably, in the step S5, when the test liquid leaks from the outside of the pipeline system to be tested, record the test pressure value at this moment, and substitute the test pressure value into the second preset calculation formula to obtain the internal pressure value of the pipeline system to be tested.

[0024] Preferably, in the step S5, when the test pressure value is greater than or equal to the critical pressure value, determine whether the test liquid in the sealing cavity leaks. If the test liquid leaks, it indicates that the pressure condition of the pipeline system to be tested is unqualified; otherwise, it indicates that the pressure condition is qualified.

[0025] Preferably, in the step S1, two connection through holes are provided. One of the connection through holes is used to inject the test liquid, and the other connection through hole is used to discharge the air in the sealing cavity.

[0026] Preferably, in the radial cross-section of the first pipe section, the two connection through holes are symmetrically arranged about the vertical center line of the first pipe section, and an included angle of 15° is formed between the axis of each connection through hole and the vertical center line of the first pipe section.

[0027] Preferably, in the step S1, diversion pipes are welded on the two connection through holes respectively, and each diversion pipe is provided with a control valve for controlling the connection or disconnection of the diversion pipe.

[0028] Preferably, in the step S4, a pressure pump is arranged on one of the diversion pipes for continuously pressurizing the sealing cavity; a pressure gauge is arranged on the other diversion pipe for measuring the test pressure value in the sealing cavity.

[0029] Preferably, the pressure test method for the multi-channel sealed pipe section further includes: S6, blocking the connection through holes and performing anti-corrosion operations on the inside and outside of the pipeline system to be tested.

[0030] Advantages of the present invention:

[0031] The pressure testing method for multi-channel sealed pipe joints proposed by the present invention connects the sealed cavity with the outside world by opening a connecting through hole on the outer wall of the first pipe joint, thereby building a channel foundation for subsequent testing operations, and directly applies the test liquid to the outside of the sealed cavity, thereby truly simulating the mechanical environment of the pipe system to be tested under external water and soil pressure during actual burial. Through the synergistic effect of the construction of the sealed cavity and the setting of the connecting through hole, only two micro connecting through holes need to be opened on the first pipe joint to establish a complete pressure transmission channel, which simplifies the complex tooling configuration required for traditional pressure testing, reduces equipment investment and manual operation intensity. The first pipe joint and the second pipe joint are coaxially docked to form the pipe system to be tested, simulating the connection state of the pipe joints in actual use. Fill the sealed cavity with test liquid and continuously pressurize it, and measure the test pressure value in real time. By using the principle of liquid transmission of pressure, pressure can be directly and effectively applied to the sealed cavity and the pressure change can be monitored. Finally, the pressure condition of the pipe system to be tested is obtained based on the leakage of the test liquid and the test pressure value. The equipment required for this test method is simple and easy to disassemble and assemble. After completing the measurement task, the tool can be quickly disassembled and conveniently transferred to the next measurement point or stored for safekeeping, which improves the operation efficiency. At the same time, without significantly damaging the pipe system to be tested, a minimally invasive measurement method is adopted. The entire measurement process only requires opening two tiny connecting holes on the first pipe section, which can effectively perform pressure tests on multiple sealed pipe sections, with low cost and high measurement efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of a pressure testing method for a multi-channel sealed pipe joint provided by an embodiment of the present invention;

[0033] Figure 2 is a first front view of the pipe system to be tested provided by an embodiment of the present invention;

[0034] Figure 3 is a first side view of the pipe system to be tested provided by an embodiment of the present invention;

[0035] Figure 4 is a second front view of the pipe system to be tested provided by an embodiment of the present invention;

[0036] Figure 5 is a second side view of the pipe system to be tested provided by an embodiment of the present invention;

[0037] Figure 6 It is a third side view of the pipe system to be tested provided by the embodiment of the present invention.

[0038] In the figure:

[0039] 1. Pipe system to be tested; 11. First pipe section; 12. Second pipe section; 13. Sealing chamber; 14. Sealing element; 15. Connecting hole; 2. Flow guide tube; 3. Control valve; 4. Booster pump; 5. Pressure gauge. Detailed implementation manners

[0040] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0041] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0042] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above the upper side", and "on the upper surface" of the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below the lower side", and "on the lower surface" of the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0043] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific implementation manners.

[0044] The embodiment of the present invention provides a pressure test method for a multi-channel sealed pipe joint, which is applied to a pipe system to be tested. The pipe system to be tested includes a first pipe joint and a second pipe joint. Two seals are arranged at intervals along the axial direction of the inner wall of the first pipe joint, and a sealed cavity is formed between the two seals.

[0045] See Figures 1 to 6 , the pressure test method for a multi-channel sealed pipe joint provided by the embodiment of the present invention includes: S1. An access through-hole 15 is opened on the outer wall of the first pipe joint 11 for communicating the sealed cavity 13 with the outside; S2. The first pipe joint 11 and the second pipe joint 12 are coaxially butted to form a pipe system 1 to be tested; S3. The sealed cavity 13 is filled with a test liquid through the access through-hole 15; S4. The sealed cavity 13 is continuously pressurized through the access through-hole 15, and the test pressure value in the sealed cavity 13 is measured in real time; S5. The pressure condition of the pipe system 1 to be tested is obtained based on the leakage condition of the test liquid and the test pressure value.

[0046] The pressure test method for multi-channel sealed pipe joints proposed by the present invention builds a channel foundation for subsequent test operations by opening a connection through-hole 15 on the outer wall of the first pipe joint 11 to connect the sealing cavity 13 with the outside world. By directly applying the test liquid to the outside of the sealing cavity 13, it truly simulates the mechanical environment in which the pipe system 1 to be tested bears external soil and water pressure during actual burial. Through the synergistic effect of the construction of the sealing cavity 13 and the setting of the connection through-hole 15, only two micro connection through-holes 15 need to be opened on the first pipe joint 11 to establish a complete pressure transmission channel, simplifying the complex tooling configuration required for traditional pressure tests and reducing equipment investment and manual operation intensity. The first pipe joint 11 and the second pipe joint 12 are coaxially butted to form the pipe system 1 to be tested, simulating the pipe joint connection state in actual use. Fill the sealing cavity 13 with the test liquid and continuously pressurize it, and measure the test pressure value in real time. Using the principle of liquid pressure transmission, the pressure can be directly and effectively applied to the sealing cavity 13 and the pressure change can be monitored. Finally, based on the leakage situation of the test liquid and the test pressure value, the pressure situation of the pipe system 1 to be tested is obtained. The equipment required for this test method is simple and easy to disassemble and assemble. After completing the measurement task, the tools can be quickly disassembled, which is convenient for transferring to the next measurement point or for storage, improving the operation efficiency. At the same time, without significantly damaging the body of the pipe system 1 to be tested, a minimally invasive measurement method is adopted. Only two small connection through-holes 15 need to be opened on the first pipe joint 11 during the whole measurement process, so as to effectively perform pressure tests on multi-channel sealed pipe joints, with low cost and high measurement efficiency.

[0047] It should be noted that this embodiment is described by taking a two-channel sealing structure as an example, specifically showing a structural form in which two sealing members 14 are arranged at intervals along the axial direction on the inner wall of the first pipe joint 11 to form a single sealing cavity 13. For other extended implementation methods with multiple seals, by increasing the number of sealing members 14 as required on the inner wall of the first pipe joint 11, a structure of multiple independent sealing cavities 13 arranged in sequence along the axial direction can be formed. A sealing cavity 13 is formed between adjacent sealing members 14, and the same test principle can be used to implement external pressure loading and sealing performance detection. Corresponding connection through-holes 15 are respectively opened for each independent sealing cavity 13. By injecting test liquid into each sealing cavity 13 and applying pressure in stages or synchronously, the failure threshold and leakage characteristics of each sealing member 14 under different external pressure conditions can be evaluated layer by layer. It should be noted that the above-mentioned two-channel sealing structure and its extended implementation methods, including but not limited to the number of sealing members 14, the arrangement method of the sealing cavities 13, and the corresponding test process, are all within the protection scope defined by the claims of the present invention.

[0048] The specific steps of the pressure test method for multi-channel sealed pipe joints will be elaborated below.

[0049] S1. Open a connection through-hole 15 on the outer wall of the first pipe section 11 for connecting the sealing cavity 13 to the outside;

[0050] Specifically, select two hole-opening points circumferentially at the top of the first pipe section 11. Based on the structural strength distribution of the first pipe section 11 and the fluid dynamic characteristics of the sealing cavity 13, set the axis of the connection through-hole 15 perpendicular to the outer surface of the first pipe section 11. Before hole-opening, use a positioning tooling to fix the first pipe section 11 to ensure that the geometric position accuracy of the first pipe section 11 is not affected during the drilling process. First, use a small-diameter drill bit to drill a pilot hole along a preset angle, and then replace it with a standard-diameter drill bit of the appropriate size to complete the final forming of the connection through-hole 15. The inner wall of the connection through-hole 15 needs to be chamfered to remove burrs to avoid damage to the sealing surface during subsequent pipeline connection.

[0051] More specifically, refer to Figure 2 and Figure 3 , in S1, two connection through-holes 15 are provided. One of the connection through-holes 15 is used for injecting test liquid, and the other connection through-hole 15 is used for discharging the air in the sealing cavity 13. By providing two independent connection through-holes 15 to respectively undertake the functions of liquid injection and air exhaust, the synchronous injection of the test liquid and the discharge of the air in the sealing cavity 13 can be realized during the liquid injection stage. When the test liquid enters the sealing cavity 13 through the connection through-hole 15 for liquid injection, the original air in the sealing cavity 13 is naturally discharged along the connection through-hole 15 for air exhaust under the displacement action of the test liquid, completely eliminating the problem of bubble retention caused by the coexistence of gas and liquid phases in the sealing cavity 13, preventing the resulting pressure fluctuations or incomplete air exhaust phenomena, ensuring the integrity and uniformity of the test liquid filling in the sealing cavity 13, and improving the test accuracy.

[0052] In this embodiment, the test liquid is preferably water, which has the characteristics of low cost, easy availability, environmental friendliness, and stable physical properties, and can meet the core requirements of conventional pressure tests for the incompressibility of the medium and the pressure transmission efficiency. In other alternative embodiments, the type of the test liquid can be adaptively adjusted according to specific test scenarios or special working conditions requirements. For example, liquids such as glycerol and hydraulic oil can be selected, which are not limited herein.

[0053] Preferably, in the radial cross-section of the first pipe section 11, the two connecting through-holes 15 are symmetrically arranged with respect to the vertical center line of the first pipe section 11, and an angle of 15° is formed between the axis of each connecting through-hole 15 and the vertical center line of the first pipe section 11. On the one hand, the design of the 15° angle not only makes the inclination angle of the connecting through-hole 15 for liquid injection beneficial to the tangential flow state of the test liquid injected into the sealing cavity 13, promotes the spiral flow of the test liquid along the inner wall of the sealing cavity 13 by using the centrifugal effect, accelerates the filling process and reduces the attachment of bubbles; but also facilitates the residual air in the sealing cavity 13 to converge along the shortest path to the highest point and be discharged from the connecting through-hole 15 under the displacement of the test liquid. On the other hand, the space complementary relationship formed by the symmetrical arrangement and inclination of the two connecting through-holes 15 enables the installation position of subsequent external devices to avoid the central line area at the top of the first pipe section 11, preventing interference between the external devices and the connecting through-holes 15.

[0054] In other embodiments, the setting parameters of the connecting through-hole 15 can be adaptively adjusted according to actual test requirements or the structural characteristics of the first pipe section 11. For example, the number of connecting through-holes 15 can be expanded to multiple to match the liquid injection efficiency and exhaust path design requirements of different sealing cavities 13; the angle between each connecting through-hole 15 can also be reset based on the dynamic characteristics of the test liquid or spatial layout limitations. In addition, the specific setting position of the connecting through-hole 15 in the circumferential direction of the first pipe section 11 can be flexibly adjusted according to conditions such as the construction environment. The adjustment of the above parameters all follows the core principle of realizing the connection between the sealing cavity 13 and the outside world through the connecting through-hole 15 in the present invention, which belongs to the equivalent deformation or extended application of the technical solution of this patent. Therefore, the specific numerical values and positional relationships should not be construed as limitations on the present invention.

[0055] To facilitate the subsequent injection of the test liquid into the sealing cavity 13 and the discharge of gas, referring to Figure 4 and Figure 5 , in S1, flow guide pipes 2 are welded to the two connecting through-holes 15 respectively. The flow guide pipes 2 provide a dedicated and stable conveying path for the test liquid, enabling the test liquid to be injected into the sealing cavity 13 more accurately and smoothly. Compared with directly injecting through the connecting through-hole 15, the flow guide pipes 2 can better guide the flow direction of the test liquid, avoid situations such as splashing and turbulent flow during the injection process, and ensure the uniformity of liquid injection into the sealing cavity 13. Each flow guide pipe 2 is equipped with a control valve 3, and the control valve 3 is used to control the connection or disconnection of the flow guide pipe 2. When it is necessary to inject the test liquid into the sealing cavity 13 or apply pressure, the control valve 3 can be opened to connect the flow guide pipe 2 to facilitate the smooth entry of the liquid; when the liquid injection is completed or it is necessary to stop the pressure application and prevent the backflow of the test liquid, etc., the control valve 3 can be closed to disconnect the flow guide pipe 2, effectively avoiding the accidental leakage of the test liquid or the uncontrolled change of pressure, and improving the controllability and stability of the test process.

[0056] S2. Coaxially dock the first pipe section 11 with the second pipe section 12 to form the pipe system 1 to be tested;

[0057] Specifically, first, accurately align the socket end of the second pipe section 12 with the spigot end of the first pipe section 11 along the axial direction. Then, use a jacking device to gradually move the first pipe section 11 and the second pipe section 12 closer until the socket is completely inserted into the spigot, thereby forming the pipe system 1 to be tested.

[0058] Preferably, after the docking of the first pipe section 11 and the second pipe section 12 is completed, a sealing clamp structure can be set at the connection between the first pipe section 11 and the second pipe section 12, so as to reinforce and seal the pipe system 1 to be tested, prevent the subsequent detachment of the first pipe section 11 and the second pipe section 12, or prevent the leakage of gas or liquid in the pipe system 1 to be tested.

[0059] S3. Fill the sealing cavity 13 with test liquid through the connection through-hole 15;

[0060] Specifically, during the liquid injection stage, the control valve 3 corresponding to the connection through-hole 15 for liquid injection remains fully open, while the control valve 3 of the connection through-hole 15 for exhaust is adjusted in stages according to the liquid injection progress: at the initial stage of liquid injection, the exhaust valve of the connection through-hole 15 for exhaust is fully open, and the air in the sealing cavity 13 is driven to rise along the diversion pipe 2 and discharged by the gravity difference; when it is observed that liquid continuously flows out of the connection through-hole 15 for exhaust, gradually close the corresponding control valve 3 to establish a backpressure environment in the sealing cavity 13, forcing the subsequent injected test liquid to evenly fill the gap of the sealing cavity 13, so that the sealing cavity 13 is filled with test liquid.

[0061] S4. Continuously pressurize the sealing cavity 13 through the connection through-hole 15 and measure the test pressure value in the sealing cavity 13 in real time;

[0062] Specifically, refer to Figure 6 , in S4, a pressure pump 4 is set on one of the diversion pipes 2, and the pressure pump 4 is used to continuously pressurize the sealing cavity 13; a pressure gauge 5 is set on the other diversion pipe 2, and the pressure gauge 5 is used to measure the test pressure value in the sealing cavity 13.

[0063] When starting to pressurize, start the pressure pump 4 installed on the diversion pipe 2. The operation of the pressure pump 4 causes the working components inside the pump to generate displacement, changing the volume of the pump cavity. With the regular change of the pump cavity volume, the test liquid is continuously sucked into the pump cavity, and when the volume of the pump cavity shrinks, under the action of pressure, it is injected into the sealing cavity 13 along the diversion pipe 2. During the injection process, due to the continuous operation of the pump, the injected test liquid accumulates continuously, causing the pressure in the sealing cavity 13 to rise continuously. During the test, the operator observes the numerical change of the pressure gauge 5 installed on the other diversion pipe 2 at all times. The reading of the pressure gauge 5 is the test pressure value, so as to evaluate the external pressure situation of the pipe section to be tested.

[0064] In this embodiment, the pressure pump 4 is a plunger pump. After the pressure pump 4 is started, the motor drives the piston of the pump body to reciprocate. When the piston moves outward, the volume of the pump chamber increases and the pressure decreases, and the test liquid is sucked into the pump chamber under the action of atmospheric pressure; when the piston moves inward, the volume of the pump chamber decreases and the pressure increases, and the test liquid is pressed into the diversion pipe 2 and then enters the sealing chamber 13, realizing continuous pressurization of the sealing chamber 13.

[0065] In other embodiments, the pressure pump 4 can also be a diaphragm pump, etc.; in addition, the pressure gauge 5 can be an existing spring pressure gauge 5 or a digital pressure gauge 5, etc., which are not limited here.

[0066] Preferably, a check valve structure is built in the output end of the pressure pump 4 to prevent the test liquid from flowing back.

[0067] S5. Obtain the pressure condition of the pipeline system 1 to be measured based on the leakage condition of the test liquid and the test pressure value.

[0068] Among them, there are two evaluation methods for the pressure condition.

[0069] The first is the external pressure limit evaluation method based on the detection of the leakage critical point of the pipeline system 1 to be measured. Its core lies in continuously pressurizing to the seal failure state and inversely deducing the actual external pressure bearing capacity of the pipeline system 1 to be measured.

[0070] Specifically, in S5, when the test liquid leaks from the inside of the pipeline system 1 to be measured, the pressure applied to the outside of the surface of the pipeline system 1 to be measured (simulated by pressurizing the test liquid into the sealing chamber 13) causes the seal of the pipeline system 1 to fail, and the test liquid leaks into the inside of the pipeline system 1 to be measured, indicating that the external pressure acts on the seal of the pipeline system 1 to be measured and breaks through the seal. Therefore, the pressure measured at this time reflects the external pressure condition of the pipeline system 1 to be measured. Therefore, when the test liquid leaks from the inside of the pipeline system 1 to be measured, record the test pressure value at this moment, and substitute the test pressure value into the first preset formula to obtain the external pressure value of the pipeline system 1 to be measured.

[0071] Since the pressure borne by the inner wall of the sealing chamber 13 comes not only from the pressure brought by pressurizing the test liquid by the pressure pump 4 (i.e., the reading of the pressure gauge 5), but also includes the pressure generated by the gravity of the test liquid in the sealing chamber 13. And because the pressure generated by the gravity of the test liquid received by the sealing chambers 13 at different positions of the pipeline system 1 to be measured is different, when the leakage position is at different positions of the pipeline system 1 to be measured, the first preset formula for calculating the external pressure value of the pipeline system 1 to be measured is also different.

[0072] Specifically, when the leakage position is at the bottom of the pipeline system 1 to be measured, the first preset formula is:

[0073]

[0074] When the leakage position is at the bottom of the pipeline system 1 to be tested, the hydrostatic pressure of the test liquid here reaches the peak value (the liquid column height The static pressure increment ΔP = ρgH, where ρ is the liquid density and g is the acceleration due to gravity). In actual engineering, the larger the outer diameter D1 of the pipeline system 1 to be tested, the higher the liquid column height H, and the static pressure increment is positively correlated with D1. Therefore, the first preset formula introduces The empirical coefficient to equivalently represent the additional pressure generated by the liquid column gravity of the test liquid at this position.

[0075] When the leakage position is in the middle of the pipeline system 1 to be tested, the first preset formula is:

[0076]

[0077] When the leakage position is in the middle of the pipeline system 1 to be tested, the liquid column height at this time The static pressure increment is about half of that when the leakage position is at the bottom of the pipeline system 1 to be tested, so the correction coefficient is adjusted to To match the static pressure contribution at this position.

[0078] When the leakage position is at the top of the pipeline system 1 to be tested, the first preset formula is:

[0079] P1 = P2

[0080] When the leakage position is at the top of the pipeline system 1 to be tested, the hydrostatic pressure approaches zero, and the test pressure value P2 can be regarded as equal to the external pressure value P1 without correction.

[0081] Wherein, P1 is the external pressure value, P2 is the test pressure value, and D1 is the outer diameter of the pipeline system 1 to be tested.

[0082] The second one is a quick acceptance test method based on a preset critical value, which is applicable to the engineering acceptance scenario where the design pressure threshold is known.

[0083] In S5, when the test pressure value is greater than or equal to the critical pressure value, it is judged whether there is leakage of the test liquid inside the pipeline system 1 to be tested. If the test liquid leaks, it indicates that the pressure condition is unqualified; otherwise, it indicates that the pressure condition is qualified. This method avoids the resource waste caused by the need to pressurize to the leakage point in the first test, which may damage the pipeline system 1, through a target-oriented pressure loading method, and is applicable to the quality sampling inspection of batch pipe joints.

[0084] For example, the set critical pressure value is 5 MPa. The pressure on the sealing cavity 13 is slowly and evenly applied by the pressure pump 4. During the pressure application process, closely monitor the numerical change of the pressure gauge 5. When the measured pressure value shown on the pressure gauge 5 reaches 5 MPa, stop further pressurization. At this time, carefully observe whether there are any signs of leakage of the test liquid in the sealing cavity 13, and comprehensively check each part of the pipe system 1 to be tested, including the sealing interface, the pipe wall, etc. If it is found that the test liquid leaks out from any part of the sealing cavity 13, such as water droplets dripping at the sealing interface or wet marks on the pipe wall, it indicates that under the external pressure of 5 MPa, the sealing performance of the sealed pipe joint cannot meet the requirements and the test liquid leaks. Then, the external pressure condition of the pipe system 1 to be tested is determined as unqualified; if after inspection, no leakage of the test liquid is found, each part of the pipe joint to be tested remains dry and there is no trace of the test liquid seeping out, this indicates that under the external pressure of 5 MPa, the pipe system 1 to be tested can effectively prevent the leakage of the test liquid and has good sealing performance, and the external pressure condition of the pipe system 1 to be tested is determined as qualified.

[0085] In S5, when the test liquid leaks from the outside of the pipe system 1 to be tested, at this time, the test pressure applied in the sealing cavity 13 (simulating the external pressure by injecting the test liquid into the sealing cavity 13 for pressurization) has exceeded the actual pressure inside the pipe system 1 to be tested, resulting in the test liquid breaking through the sealing structure in the reverse direction and leaking to the outside of the pipe system 1 to be tested. Therefore, the pressure measured at this time reflects the internal pressure condition of the pipe system 1 to be tested. Therefore, when the test liquid leaks from the outside of the pipe system 1 to be tested, record the test pressure value at this moment, and substitute the test pressure value into the second preset calculation formula to obtain the internal pressure value of the pipe system 1 to be tested.

[0086] It can be understood that in this embodiment, the situation and calculation process of the second preset calculation formula are the same as those of the first preset calculation formula, and will not be elaborated here.

[0087] S6. Block the connection through-hole 15, and perform anti-corrosion operations on the inside and outside of the pipe system 1 to be tested.

[0088] Specifically, first, a grinding wheel is used to precisely cut along the welding interface between the diversion pipe 2 and the pipe system 1 to be measured, stripping the main structure of the diversion pipe 2 while avoiding mechanical damage to the outer wall of the pipe system 1 to be measured outside the heat-affected zone. After cutting, the arc welding process is used to fill the connecting through-hole 15 by multi-layer surfacing welding. During the welding process, the interlayer temperature and bead formation are strictly controlled to ensure that the metallographic structure of the sealing area is consistent with that of the base metal and eliminate the risk of stress concentration caused by welding defects. The welded scar after filling is subjected to multi-stage grinding treatment with a bench grinder, successively using rough grinding, fine grinding, and polishing processes to make the repaired surface smoothly transition to the original contour of the pipe system 1 to be measured, and the roughness reaches the standard of the outer wall of the original pipe system 1 to be measured. Finally, synchronous internal and external anti-corrosion treatment is implemented on the repaired area. The outer wall of the pipe system 1 to be measured is coated in layers with an anti-corrosion paint matching the original coating system of the pipe system 1 to be measured, and the inner wall of the pipe system 1 to be measured is coated with a pressure-resistant anti-corrosion material by spraying or brushing to ensure that the corrosion resistance and mechanical strength of the repaired part are fully restored to the initial state of the pipe system 1 to be measured.

[0089] The above embodiments only illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, there are various changes and modifications to the present invention, and these changes and modifications all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A pressure test method for multi-channel sealed pipe sections, which is applied to a pipe system to be tested (1), the pipe system to be tested (1) includes a first pipe section (11) and a second pipe section (12), and two seals (14) are arranged at intervals along the axial direction of the inner wall of the first pipe section (11), and a sealed cavity (13) is formed between the two seals (14), characterized in that, The pressure test method for multi-channel sealed pipe sections includes: S1. Open a connection through-hole (15) on the outer wall of the first pipe section (11) for communicating the sealing cavity (13) with the outside; S2. Docking the first pipe section (11) and the second pipe section (12) coaxially to form the pipe system to be tested (1); S3. Fill the sealing cavity (13) with test liquid through the connection through-hole (15); S4. Continuously pressurize the sealing cavity (13) through the connection through-hole (15), and measure the test pressure value in the sealing cavity (13) in real time; S5. Obtain the pressure condition of the pipe system to be tested (1) based on the leakage condition of the test liquid and the test pressure value.

2. The pressure testing method for multi-channel sealed pipe joints according to claim 1, wherein In S5, when the test liquid leaks from the inside of the pipe system to be tested (1), record the test pressure value at this moment, and substitute the test pressure value into the first preset formula to obtain the external pressure value of the pipe system to be tested (1).

3. The pressure testing method for multi-channel sealed pipe joints according to claim 2, characterized in that, When the leakage position is at the bottom of the pipe system to be tested (1), the first preset formula is: When the leakage position is in the middle of the pipe system to be tested (1), the first preset formula is: When the leakage position is at the top of the pipe system to be tested (1), the first preset formula is: P1 = P2 Wherein, P1 is the external pressure value, P2 is the test pressure value, and D1 is the outer diameter of the pipe system to be tested (1).

4. The pressure testing method for multi-channel sealed pipe joints according to claim 1, characterized in that, In S5, when the test liquid leaks from the outside of the pipe system to be tested (1), record the test pressure value at this moment, and substitute the test pressure value into the second preset formula to obtain the internal pressure value of the pipe system to be tested (1).

5. The pressure testing method for multi-channel sealed pipe joints according to claim 1, characterized in that, In S5, when the test pressure value is greater than or equal to the critical pressure value, determine whether the test liquid in the sealing cavity (13) leaks. If the test liquid leaks, it indicates that the pressure condition of the pipe system to be tested (1) is unqualified; otherwise, it indicates that the pressure condition is qualified.

6. The pressure testing method for multi-channel sealed pipe joints according to claim 1, characterized in that In S1, two connection through-holes (15) are opened. One of the connection through-holes (15) is used for injecting test liquid, and the other connection through-hole (15) is used for discharging the air in the sealing cavity (13).

7. The pressure test method for multi-channel sealed pipe joints according to claim 6, characterized in that, In the radial cross-section of the first pipe section (11), the two connection through-holes (15) are symmetrically arranged with respect to the vertical center line of the first pipe section (11), and an angle of 15° is formed between the axis of each connection through-hole (15) and the vertical center line of the first pipe section (11).

8. The pressure test method for multi-channel sealed pipe joints according to claim 6, characterized in that, In S1, flow guide pipes (2) are welded on the two connection through-holes (15) respectively, and each flow guide pipe (2) is provided with a control valve (3), and the control valve (3) is used to control the connection or disconnection of the flow guide pipe (2).

9. The pressure testing method for multi-channel sealed pipe joints according to claim 8, characterized in that, In S4, a pressure pump (4) is arranged on one of the flow guide pipes (2), and the pressure pump (4) is used to continuously pressurize the sealing cavity (13); A pressure gauge (5) is arranged on the other flow guide pipe (2), and the pressure gauge (5) is used to measure the test pressure value in the sealing cavity (13).

10. The pressure testing method for multi-channel sealed pipe joints according to any one of claims 1-9, characterized in that, The pressure test method for multi-channel sealed pipe joints further includes: S6. Block the connection through-hole (15), and perform anti-corrosion operations on the inside and outside of the pipe system (1) to be tested.

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