Device capable of measuring underpressure and overpressure of elastic sealing gasket at flange joint

Abstract

The invention provides a device capable of measuring underpressure and overpressure of an elastic sealing gasket at a flange joint, a pressure stress test hole is formed in the outer surface of the edge of the elastic sealing gasket, and a pressure stress test plate matched with the inner wall of the pressure stress test hole is arranged in the pressure stress test hole. The pressure stress test plate in the pressure stress test hole is parallel to the pressed surface of the elastic sealing gasket; the end part, extending out of the pressure stress testing hole, of the pressure stress testing plate is provided with a wiring part, and the wiring part is connected with an under-voltage testing rope and an over-voltage testing rope. According to the invention, the under-pressure test rope and the over-pressure test rope respectively correspond to the fracture or intact condition during the drawing test, so that whether the actual pressure stress on the elastic sealing gasket meets the requirement relative to a specified value can be timely, simply and effectively judged, and the under-pressure and over-pressure conditions are avoided; therefore, the safe sealing performance and effectiveness of the elastic sealing gasket are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline engineering, and in particular to a device capable of measuring underpressure and overpressure of an elastic sealing gasket at a flange connection. Background Art

[0002] In pipeline engineering, flange connection is one of the most common connection forms to prevent leakage at pipeline joints. The elastic gasket achieves sealing by extruding the elastic gasket evenly with two parallel flange extrusion surfaces, so that the gasket is evenly compressed and reaches the stress value recommended by the elastic gasket manufacturer to play a sealing role.

[0003] However, the following deficiencies still exist in the current actual construction: First, the use of traditional flange elastic gaskets cannot directly determine whether the elastic gasket is in an under-pressure state and has a risk of leakage, and cannot timely and effectively determine whether a specific part of the elastic gasket has truly reached the compressive stress value required for effective sealing recommended by the elastic gasket manufacturer during the gasket installation process, resulting in quality problems in pipeline installation; Second, it is impossible to effectively determine whether various parts of the elastic gasket exceed the upper limit of the normal use pressure of the gasket recommended by the elastic gasket manufacturer, and whether there is a risk of affecting the normal service life of the elastic gasket and causing the gasket to fail prematurely and leak during the use of the pipeline; Third, there is no method to quickly, intuitively and effectively detect the installation quality of the elastic gasket to verify the final installation quality, and a large amount of water needs to be consumed for pressure testing, which has adverse effects on environmental protection, construction costs and progress control, and the safety of deep trench workers. Summary of the invention

[0004] The purpose of the present invention is to provide a detection device which can intuitively and effectively determine whether the actual compressive stress value of a certain area of ​​an elastic sealing gasket deviates from the numerical range and causes underpressure or overpressure problems.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] A device capable of measuring underpressure and overpressure of an elastic sealing gasket at a flange connection, wherein a pressure stress test hole is provided on the outer surface of the edge of the elastic sealing gasket, wherein a pressure stress test plate cooperating with the inner wall of the pressure stress test hole is arranged in the pressure stress test hole, and the pressure stress test plate in the pressure stress test hole is arranged parallel to the pressure-bearing surface of the elastic sealing gasket; a wiring portion is provided at the end of the pressure stress test plate extending out of the pressure stress test hole, and an underpressure test rope and an overpressure test rope are connected to the wiring portion, and the underpressure test rope and the overpressure test rope are in a broken state or a complete state when the pressure stress test plate is pulled for testing, and the underpressure test rope in the broken state corresponds to an actual pressure stress greater than the lower limit value of the required pressure stress when the elastic sealing gasket is sealed, and the overpressure test rope in the broken state corresponds to an actual pressure stress greater than the upper limit value of the required pressure stress when the elastic sealing gasket is sealed, so that the elastic sealing gasket can intuitively reflect its actual pressure stress condition in this area.

[0007] Furthermore: the roughness of the compressed surfaces on both sides of the compressive stress test plate is consistent.

[0008] Furthermore: a hole is opened in the wiring part, so that the undervoltage test rope and the overvoltage test rope are wound and connected to be arranged on the wiring part.

[0009] Furthermore: the ends of the undervoltage test rope and the overvoltage test rope away from the wiring portion are both connected with pull rings.

[0010] Furthermore: the pulling priority of the undervoltage test rope is higher than the pulling priority of the overvoltage test rope.

[0011] Furthermore: the length of the undervoltage test rope is different from the length of the overvoltage test rope, so as to distinguish the undervoltage test rope from the overvoltage test rope.

[0012] Furthermore: there is a gap between the compressive stress testing hole and the pressure-bearing surfaces on both sides of the elastic sealing pad.

[0013] Furthermore, a group of compressive stress test holes are arranged on the outer surface of the edge of the elastic sealing pad, so as to determine the actual compressive stress value of the elastic sealing pad in each specific single area.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention equips the compressive stress test plate with an underpressure test rope for detecting the lower limit of the compressive stress value and an overpressure test rope for detecting the upper limit of the compressive stress value. During the pull-out test, the underpressure and overpressure test ropes are broken or intact respectively, thereby timely, simply and effectively judging whether the actual compressive stress of the elastic sealing gasket meets the requirements relative to the specified value, thereby avoiding underpressure and overpressure, thereby ensuring the safety, sealing and effectiveness of the elastic sealing gasket. At the same time, it can also avoid consuming a large amount of water for pressure testing, shorten the construction period, and effectively control environmental protection, construction costs and progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view structural schematic diagram of the present invention;

[0017] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention;

[0018] Figure 3 This is a front view schematic diagram of the structure used in actual installation of the present invention;

[0019] Figure 4 This is a schematic diagram of the cross-sectional structure of the present invention when actually installed.

[0020] The markings in the attached drawings are: 1-compression stress test plate; 2-underpressure test rope; 3-overpressure test rope; 4-pull ring; 5-elastic sealing pad; 6-compression stress test hole. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0022] like Figure 1-4 As shown, a device for measuring underpressure and overpressure of an elastic sealing gasket at a flange connection is provided, wherein a pressure stress test hole 6 is provided on the outer surface of the edge of the elastic sealing gasket 5, and a pressure stress test plate 1 matching with the inner wall thereof is arranged in the pressure stress test hole 6, and the pressure stress test plate 1 in the pressure stress test hole 6 is arranged parallel to the pressure-bearing surface of the elastic sealing gasket 5; a wiring portion is provided at the end of the pressure stress test plate 1 extending out of the pressure stress test hole 6, and an underpressure test rope 2 and an overpressure test rope 3 are connected to the wiring portion, and the underpressure test rope 2 and the overpressure test rope 3 are in a broken state or a complete state when the pressure stress test plate 1 is pulled out for testing, and the underpressure test rope 2 in the broken state corresponds to an actual pressure stress greater than the lower limit value of the required pressure stress when the elastic sealing gasket 5 is sealed, and the overpressure test rope 3 in the broken state corresponds to an actual pressure stress greater than the upper limit value of the required pressure stress when the elastic sealing gasket 5 is sealed, so that the elastic sealing gasket 5 can intuitively reflect its actual pressure stress condition in this area.

[0023] A group of compressive stress test holes 6 are arranged on the outer surface of the edge of the elastic sealing pad 5 so as to determine the actual compressive stress value of the elastic sealing pad 5 in each specific single area.

[0024] Specifically, the roughness of the compressed surfaces on both sides of the compressive stress test plate 1 is consistent. During processing, grinding starts with a coarser abrasive paste and ends with grinding using F3000 (6μm) or W7 (5-7μm) abrasive paste, that is, the flatness of the upper and lower surfaces reaches a uniform precision-level brightness.

[0025] In this embodiment, the compressive stress test plate 1 has a thickness of 0.2 mm, and the plane dimensions are mainly 125 mm long, 4 mm wide, 100 mm long, 5 mm wide, 50 mm long, 10 mm wide, and 25 mm long, 20 mm wide. The single-side pressure area is 500 mm. 2 At the same time, the surface roughness of each surface in the pressure stress test hole 6 is consistent, and the internal surface roughness of the pressure stress test holes 6 of different types of elastic sealing pads 5 is preferably consistent. The cross-sectional shape of the opening of the pressure stress test hole 6 is rectangular, the opening height is uniformly 0.2mm, and its width and depth are consistent with the cross-sectional dimensions of the pressure test plate 1 used in pairing.

[0026] like Figure 1-2 As shown, specifically, a hole is opened in the wiring part, so that the undervoltage test rope 2 and the overvoltage test rope 3 are wound and connected through the hole and are arranged on the wiring part.

[0027] Specifically, the ends of the undervoltage test rope 2 and the overvoltage test rope 3 away from the wiring portion are both connected with pull rings 4.

[0028] In this embodiment, the underpressure test rope 2 and the pull ring 4 are connected to the pressure stress test plate 1; when the pressure value borne by the pressure stress test plate 1 is exactly equal to the lower limit value of the pressure stress required for the elastic sealing gasket 5 to effectively seal, the sliding friction force to which the pressure stress test plate 1 is subjected when it is pulled out of the pressure stress test hole 6 is equal to the tension value that the underpressure test rope 2 can withstand when it breaks; the overpressure test rope 3 and the pull ring 4 are connected to the pressure stress test plate 1; when the pressure value borne by the pressure stress test plate 1 is exactly equal to the upper limit value of the pressure stress required for the elastic sealing gasket 5 to effectively seal, the sliding friction force to which the pressure stress test plate 1 is subjected when it is pulled out of the pressure stress test hole 6 is equal to the tension value that the overpressure test rope 3 can withstand when it breaks.

[0029] Specifically, the pulling priority of the undervoltage test rope 2 is higher than the pulling priority of the overvoltage test rope 3 .

[0030] Among them, the length of the undervoltage test rope 2 is greater than that of the overvoltage test rope 3, so that the user can distinguish the undervoltage test rope 2 and the overvoltage test rope 3 to determine the priority pulling order by first pulling the longer undervoltage test rope 2 and then pulling the overvoltage test rope 3.

[0031] Specifically, there is a gap between the pressure stress test hole 6 and the pressure-bearing surfaces on both sides of the elastic sealing pad 5. It is best to be arranged at the middle height position of the elastic sealing pad 5.

[0032] In this embodiment, the mechanical relationship between the actual pressure value of the elastic sealing pad 5 and the pull force of the corresponding compressive stress test plate 1 from the compressive stress test hole 6 set at the edge of the elastic sealing pad 5 can be obtained according to the sliding friction calculation formula. The corresponding mechanical principle is as follows:

[0033] f=μ×N

[0034] Wherein: μ is the friction coefficient between the upper and lower surfaces of the stress test plate 1 and the contact surfaces with the same friction coefficient in the stress test hole 6. Since the upper and lower surfaces of the stress test plate 1 are ground to a uniform precision surface with F3000 (6μm) or W7 grade (5-7μm) grinding paste, the roughness of the upper and lower surfaces is uniformly smooth. Therefore, the friction coefficients of the upper and lower surfaces of the stress test plate 1 and the inner surface of the stress-bearing end of the elastic sealing pad 5 in contact are uniform. For ease of use, the friction coefficient between the surface of the stress test plate 1 and the inner surface of the stress test hole 6 can be calibrated by the manufacturer through a standard test before use;

[0035] N is the vertical pressure applied to the upper and lower surfaces of the compressive stress test plate 1;

[0036] f is the maximum tensile force causing sliding friction between the compressive stress test plate 1 and the elastic sealing pad 5 .

[0037] Since the actual compressive stress of the elastic sealing pad 5 after installation is calculated as P 实际 =N / A, where N represents the pressure exerted on the compressive stress test plate 1 by the elastic sealing pad 5 , and A represents the horizontal surface area of ​​one side of the compressive stress test plate 1 .

[0038] Since the upper and lower surfaces of the compressive stress test plate 1 are subjected to friction at the same time, the tensile force T measured at the moment when the compressive stress test plate 1 is pulled should be twice the friction force on one side of the compressive stress test plate 1. Therefore, the actual compressive stress calculation formula of the installed elastic sealing gasket 5, Pactual=N / A, is substituted into the friction calculation formula to obtain:

[0039] After simplification

[0040]

[0041] The present invention is based on the effective sealing stress value P of the elastic sealing gasket 5 recommended by the elastic sealing gasket manufacturer. 推荐下限 and P 推荐上限The underpressure test rope 2 and the overpressure test rope 3 are customized so that when the effective sealing stress value of the elastic sealing pad is less than P 推荐下限 When the entire compressive stress test plate 1 is completely pulled out, the steel wire of the under-pressure test rope 2 is not broken. This method can quickly determine whether the installation compressive stress of the flange elastic sealing gasket 5 is under-pressure; when the effective sealing stress value of the elastic sealing gasket is greater than P 推荐下限 and less than P 推荐上限 When the pressure test rope 3 is pulled, the entire pressure stress test plate 1 cannot be pulled out. Then, when the pressure test rope 3 is pulled, it does not break, and the entire pressure stress test plate 1 is pulled out completely. This method can quickly determine whether the installation pressure stress of the flange elastic sealing gasket 5 can reach the effective stress value and make the pressure of the elastic sealing gasket 5 within the range that does not affect the normal service life; when the effective sealing stress value of the elastic sealing gasket 5 exceeds P 推荐上限 When the overpressure test rope 3 is pulled, it breaks and the compressive stress test plate 1 cannot be pulled out. This method can quickly determine whether the installation compressive stress of the elastic sealing gasket 5 exceeds the range of normal service life and whether the elastic sealing gasket 5 has compressive stress overpressure that affects the normal service life of the sealing gasket.

[0042] Based on the above content, compared with the traditional flange sealing gasket 5 and installation quality judgment, the detection device avoids the problem of being unable to verify the final installation quality in a fast, intuitive and effective way and requiring a large amount of water to be consumed for pressure testing of flange sealing gasket leakage. It not only avoids wasting a large amount of water resources, related machinery and instrument investment, and the time required to drain the water and reinforce or dismantle the flange connection after leakage is found, replace the elastic sealing gasket 5, and fill the pipeline with water again to perform pressure testing until the installation quality is qualified, but also avoids the collapse of large deep trench working surfaces due to rainfall in the rainy season, which has an adverse effect on the safety of deep trench workers, saves a large amount of water resources, shortens the construction period, reduces labor and machinery investment, and has a significant improvement effect on environmental protection, construction costs and progress control, and safety management.

[0043] See also Figure 1-4 When the detection device detects underpressure and overpressure of the elastic sealing gasket at the flange connection, the specific method is as follows:

[0044] At the location where the actual compressive stress value of the elastic sealing gasket 5 needs to be measured, the compressive stress test plate 1 is fully inserted into the compressive stress test hole 6 at the edge of the elastic sealing gasket 5, and then all bolts are tightened according to the prescribed sequence and tightening torque value;

[0045] First, slowly pull the pull ring 4 connected to the underpressure test rope 2 outward along the radial direction of the flange in a plane parallel to the pressure surface of the elastic sealing gasket 5. When the pull ring 4 of the underpressure test rope 2 can pull out the pressure stress test plate 1 completely without the underpressure test rope 2 breaking, it means that the actual pressure stress on the elastic sealing gasket is lower than the specified value and there is a risk of leakage, and the bolts need to be tightened;

[0046] When the pull ring 4 of the underpressure test rope 2 is completely pulled out and the underpressure test rope 2 is broken, the pull ring 4 connected to the overpressure test rope 3 is pulled, and the pressure stress test plate 11 can be completely pulled out but the overpressure test rope 3 is not broken, it means that the actual pressure stress on the elastic sealing gasket 5 has reached the specified pressure stress value of the sealing gasket and there is no situation where the sealing gasket is over-pressurized and affects its service life;

[0047] When the pull ring 4 of the overpressure test rope 3 is pulled, and the pressure stress test plate 1 cannot be pulled out completely and the overpressure test rope 3 breaks, it means that the actual pressure stress on the elastic sealing gasket 5 has exceeded the upper limit value of the pressure stress required for the elastic sealing gasket 5 to effectively seal, and the sealing gasket is over-pressurized.

[0048] The above embodiment is only a preferred technical solution of the present invention. Those skilled in the art should understand that the technical solutions or parameters in the embodiments can be modified or replaced without departing from the principle and essence of the present invention, and all should be covered within the protection scope of the present invention.

Claims

1. A device for measuring underpressure and overpressure of elastic sealing gaskets at flange connections, characterized in that: A compressive stress test hole (6) is provided on the outer surface of the edge of the elastic sealing gasket (5), a compressive stress test plate (1) matched with the inner wall of the compressive stress test hole (6) is arranged in the compressive stress test hole (6), and the compressive stress test plate (1) in the compressive stress test hole (6) is arranged parallel to the pressure-bearing surface of the elastic sealing gasket (5); A connection portion is provided at the end of the pressure stress test plate (1) extending out of the pressure stress test hole (6), and an underpressure test rope (2) and an overpressure test rope (3) are connected to the connection portion. The underpressure test rope (2) and the overpressure test rope (3) are in a broken state or a complete state when the pressure stress test plate (1) is pulled for testing. When the underpressure test rope (2) is in a broken state and the actual pressure stress of the elastic sealing gasket (5) is greater than the lower limit value of the required pressure stress when the underpressure test rope (2) is sealed, the actual pressure stress of the elastic sealing gasket (5) is greater than the upper limit value of the required pressure stress when the overpressure test rope (3) is in a broken state and the actual pressure stress of the elastic sealing gasket (5) is greater than the upper limit value of the required pressure stress when the overpressure test rope (3) is in a broken state and the actual pressure stress of the elastic sealing gasket (5) is sealed, so that the actual pressure stress condition of the elastic sealing gasket (5) can be intuitively reflected in this area.

2. A device for measuring underpressure and overpressure of elastic sealing gaskets at flange connections according to claim 1, characterized in that: The roughness of the pressure-bearing surfaces on both sides of the compressive stress testing plate (1) is consistent.

3. A device for measuring underpressure and overpressure of elastic sealing gaskets at flange connections according to claim 1, characterized in that: A hole is provided in the wiring portion so that the undervoltage test rope (2) and the overvoltage test rope (3) are wound and connected to be arranged on the wiring portion.

4. The device for measuring underpressure and overpressure of elastic sealing gasket at flange connection according to claim 1, characterized in that: The ends of the undervoltage test rope (2) and the overvoltage test rope (3) away from the wiring portion are both connected with a pull ring (4).

5. The device for measuring underpressure and overpressure of elastic sealing gasket at flange connection according to claim 1, characterized in that: The pulling priority of the undervoltage test rope (2) is higher than the pulling priority of the overvoltage test rope (3).

6. The device for measuring underpressure and overpressure of elastic sealing gasket at flange connection according to claim 1, characterized in that: The length of the undervoltage test rope (2) is different from the length of the overvoltage test rope (3) so as to distinguish the undervoltage test rope (2) from the overvoltage test rope (3).

7. The device for measuring underpressure and overpressure of elastic sealing gasket at flange connection according to claim 1, characterized in that: There is a gap between the compressive stress testing hole (6) and the pressure-bearing surfaces on both sides of the elastic sealing pad (5).

8. The device for measuring underpressure and overpressure of elastic sealing gasket at flange connection according to claim 1, characterized in that: The compressive stress test holes (6) are arranged in a group on the outer surface of the edge of the elastic sealing pad (5) so as to determine the actual compressive stress value of the elastic sealing pad (5) in each specific single area.

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