An integrated valve group for taking pressure from orifice plate of industrial pipeline

Abstract

The invention discloses an industrial pipeline orifice plate pressure-taking integrated valve group in the field of petrochemical technology, comprising a pressure-taking flange and a pressure-taking main valve and a pressure-taking auxiliary valve installed on the pressure-taking flange, wherein the pressure-taking main valve is a first sealing valve for cutting off the pressure-taking flow path, and the pressure-taking auxiliary valve is a second sealing valve for cutting off the pressure-taking flow path, and the flow paths of the two valves are both designed as bottom-sealed angle valve structures; the bottom flow path of the pressure-taking main valve is directly connected to the pressure-taking hole of the pressure-taking orifice plate, and the bottom of the pressure-taking auxiliary valve is opened in the bottom valve body chamber of the pressure-taking main valve, and after the main valve is closed and cut off, the pressure-taking flow path is completely cut off, and after the auxiliary valve is cut off, the pressure-taking flow path is also completely cut off, and the main valve and the auxiliary valve form a series double cutoff in the pressure-taking flow path. The technical problems of unsightly layout and potential safety hazards in the prior art are solved.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to an industrial pipeline orifice plate pressure taking integrated valve group. Technical Background

[0002] In the petrochemical industry, orifice plates are widely used as the main flow measurement instrument. Orifice plates are often arranged on pipe bridges because of the requirement of long front and rear straight pipe sections. Pipe bridges are often areas where pipelines are densely arranged, and usually multiple layers of pipelines are arranged closely in parallel. Orifice pressure nipples are generally forged with special processing, with an "S" type structure or one long and one short, with a length of about 150 to 180 mm. The nipples are welded to the pressure valve. The minimum diameter of the pressure valve is DN15 and the length is about 230 mm. When the pressure valve uses a DN20 valve, the size will be larger. The pressure valve manufacturer also needs to bring 150 mm long welding nipples at both ends and add pipe clamps to weld with the orifice pressure nipples, resulting in a clearance requirement of about 500 to 900 mm for the root valve extension of each pressure point. When double valves are required to cut off and seal tightly, the extension distance is larger, and there are many welds, which are prone to leakage and crowded space layout.

[0003] When the double valve sealing nipple and two pressure valves are required to be connected to the pressure flange, the weight of these connectors will produce a great stress on the flange. On the small-diameter orifice plate, in addition to the turning holes required for fastening bolts, the pressure holes must also be turned. The strength requirements for the pressure flange will be more stringent. Insufficient strength can easily cause the flange to crack, resulting in the leakage of flammable and toxic media and causing danger. At present, the main method to solve this type of problem is to add additional support to the root valve to make the space layout more dense. The layout of the space has always been a difficult problem to solve. In the actual on-site construction stage, the solution to this type of collision is to use elbows and pipes to replace the nipple, or to bypass the obstacle according to the space and then add the root valve, and place the root valve at a farther position and add additional support. Or the piping will add elbows to the colliding pipes to bypass the root valve layout area. The layout is not beautiful, and the pipe is weaker than the nipple. When the valve is activated or the pipeline vibrates greatly, it is easy to cause the welding to loosen, posing a safety hazard. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an integrated valve group for orifice pressure taking of industrial pipelines, so as to solve the technical problems of unsightly layout and potential safety hazards in the prior art. The structure of the pressure taking flange and the pressure taking valve is designed to be integrated and compact, the pressure taking nipple is eliminated, the root valve and the pressure taking flange are designed to be integrated, and the orifice plate is partially thickened to enhance the strength of the structure itself. Through the special design of the valve body, a double valve sealing effect is formed to prevent internal leakage. The special two-way sealing design of the valve stem prevents external leakage. Through the design of the special arc-shaped slot on the hexagon of the valve body fastening, the connection between the valve body and the pressure taking flange is a double reinforcement method of threaded fastening and external bolt fastening, so that the valve body has better sealing and stronger high pressure resistance.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] An integrated pressure-taking valve group for an orifice plate of an industrial pipeline includes a pressure-taking flange and a pressure-taking main valve and a pressure-taking auxiliary valve installed on the pressure-taking flange. The pressure-taking main valve is the first sealing valve that cuts off the pressure-taking flow path, and the pressure-taking auxiliary valve is the second sealing valve that cuts off the pressure-taking flow path. The flow path designs of the two valves are both bottom-sealed angle valve structures; the bottom flow path of the pressure-taking main valve is directly connected to the pressure-taking hole of the pressure-taking orifice plate, and the bottom of the pressure-taking auxiliary valve is opened in the bottom valve body chamber of the pressure-taking main valve. After the main valve is closed and cut off, the pressure-taking flow path is completely cut off. After the auxiliary valve is cut off, the pressure-taking flow path is also completely cut off. The main valve and the auxiliary valve form a series double cutoff in the pressure-taking flow path, which can ensure the tight closure of the valve without internal leakage. The main valve body and the auxiliary valve body are integrally assembled on the pressure-taking flange, which is an innovation of the present invention. The pressure-taking flange, the pressure-taking main valve, and the pressure-taking auxiliary valve form a compact integrated structure, which saves space and reduces welding.

[0007] The invention discloses an integrated valve group for taking pressure of an orifice plate of an industrial pipeline, which is further characterized in that an external pressure taking hole is also arranged on the pressure taking flange, and a pressure taking nipple is installed on the external pressure taking hole.

[0008] The present invention is an industrial pipeline orifice plate pressure-taking integrated valve group, which is further characterized in that: the structures of the pressure-taking main valve and the pressure-taking auxiliary valve are the same, and are composed of a valve body, a valve body sealing gasket, a valve body fastening hexagon, a valve body fixing bolt, a compression nut, a stuffing box compression cover, a high-elastic gasket, a stuffing box, a valve stem, an upper sealing valve core, a lower sealing valve core, and a pass needle. The valve body, the valve body fastening hexagon, the valve body sealing gasket, and the valve body fixing bolt form a fastening structure of the valve body. After the valve body is screwed into the pressure-taking flange to compress the valve body sealing gasket, the valve body fixing bolt can still be used to continue to double-tighten the valve body.

[0009] The present invention discloses an integrated valve group for taking pressure from an orifice plate of an industrial pipeline, which is further characterized in that the clamping nut, stuffing box clamping cover, high elastic gasket, stuffing box, valve stem, upper sealing valve core, lower sealing valve core and pass needle constitute a sealing mechanism of the valve core assembly, and the clamping nut is screwed into the interior of the valve body through a thread to clamp the stuffing box, the clamping cover, the high elastic gasket and the stuffing box, and a seal is formed around the valve stem through deformation of the stuffing box, so that when the valve stem moves up and down, it will not leak outside at the gap between the valve stem and the clamping nut.

[0010] The present invention is an industrial pipeline orifice plate pressure-taking integrated valve group, which is further characterized in that: an arc-shaped slot is also provided on the main body valve body fastening hexagon, and the arc-shaped slot is designed to be 2 to 4. The valve body can not only be thread-sealed with the pressure-taking flange body through the valve body outer thread, but also can be fixed with the valve body fixing bolts at the same time, so as to achieve the effect of double fastening and sealing, so that the valve body can be used in high-pressure and tight sealing occasions.

[0011] The present invention discloses an integrated valve group for taking pressure from an orifice plate of an industrial pipeline, which is further characterized in that an upper sealing valve core and a lower sealing valve core are arranged on the valve stem, which can form a two-way seal on the flow path chamber at the bottom of the valve body, and when the flow path is opened, the stuffing box is prevented from being pressurized for a long time and leaking, so that the structure is more suitable for occasions where toxic media require strict sealing and no leakage.

[0012] The present invention discloses an integrated valve group for taking pressure from an orifice plate of an industrial pipeline, which is further characterized in that a pass needle is arranged under the valve stem, so that the structure can be used to self-clean solid particles entering into the flow path of the pressure taking hole to ensure smooth flow of the flow path.

[0013] The advantages of the present invention compared with the prior art are:

[0014] 1. The integrated design of valve group and pressure flange eliminates the pressure nipple and does not require a large number of welding points, thus preventing leakage caused by welding points in front of the pressure valve and facilitating construction.

[0015] 2. The integrated and compact design takes up little space and effectively prevents collision in space layout.

[0016] 3. Each pressure-taking flow path can be cut off by double valves. With special usage methods, double isolation can be achieved on the orifice flange body, which is effective in preventing internal leakage and further ensures the safe sealing of the cutoff.

[0017] 4. The connection between the pressure taking valve body and the pressure taking flange body adopts straight thread connection and sealing gasket, plus specially designed arc groove and valve body fixing bolts for double reinforcement. This structure can form a blow-out prevention structure for the valve body, which is suitable for high-pressure occasions.

[0018] 5. Because the pressure-taking hole of the design structure of the present invention directly serves as the sealing position of the valve core, which is only 5 to 8 mm, and the valve core structure is an angle valve structure, compared with conventional gate valve or ball valve type pressure-taking valves, the pressure-bearing area is small and it is easier to withstand high pressure.

[0019] 6. The special valve stem bidirectional sealing technology of the present invention ensures that the micro-leakage of the medium caused by the valve stem, the only moving part, can prevent the corrosion of the packing and the external leakage caused by the threads on the valve stem. The valve stem has a small movable stroke and the wear on the packing is small. When the normal flow path is fully open, the upper seal prevents the packing from being compressed, preventing external leakage, and is suitable for toxic media occasions.

[0020] 7. The pressure taking valve is integrated with the pressure taking flange. When the medium is an easily condensable medium that needs heating, because the steam heating pipe is a steel pipe, when it is wrapped around the irregular pressure taking valve, it is often not tightly enough, and blockage often occurs between the pressure taking nipple and the root valve. The on-site solution is to use a softer electric heating tape to wrap it tightly, which limits the flexibility of heating. The root valve of the present invention has good heat transfer effect due to its integrated structure. The integrated structure does not require a heating pressure taking nipple and a root valve. When the nipple is directly welded to the isolation tank, it is easier to achieve self-heating.

[0021] 8. The valve body can be replaced as a whole, which is convenient for repair and maintenance.

[0022] 9. The valve body and the pressure flange share a base, which can effectively save steel.

[0023] 10. When used for ultra-high pressure of 2500 pounds, the present invention can be designed with a special structure. The valve body can be fixed to the pressure flange base by thread and sealing welding to ensure safety, but the clamping nut can be removed to replace the packing, which is convenient for maintenance.

[0024] 11. The sealing structure under the valve core of the present invention is an angle valve structure, which allows for optimized design when used for media containing solid particles. A special structure needle is designed at the root of the valve stem to clean the flow path, ensuring that the flow path is unobstructed without affecting the seal.

[0025] 12. The integrated structure reduces the stress of the pressure taking valve on the pressure taking flange when the pipeline vibrates greatly, which is beneficial to safety.

[0026] 13. The present invention relies on existing technology and processing and manufacturing resources, and the structural design is reasonable and feasible. The function realization method and principle given by the present invention do not limit specific size requirements, and the implementation is flexible and easy to process and manufacture.

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the scope of application of the present invention is not limited thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a sectional view of the overall assembly of the industrial pipeline orifice plate pressure-taking integrated valve group of the present invention;

[0029] Figure 2 It is a top view of the overall assembly of the integrated valve group for taking pressure from an orifice plate of an industrial pipeline according to the present invention;

[0030] Figure 3 It is a side view of the industrial pipeline orifice plate pressure-taking integrated valve group of the present invention for taking pressure at a 45-degree angle along the pipeline direction;

[0031] Figure 4 It is a side view of the industrial pipeline orifice plate pressure-taking integrated valve group of the present invention for taking pressure at a 45-degree angle along the pipeline direction;

[0032] Figure 5 It is a bidirectional sealing structure diagram of the valve body of the industrial pipeline orifice plate pressure-taking integrated valve group of the present invention;

[0033] Figure 6 It is a packing assembly diagram of the industrial pipeline orifice plate pressure-taking integrated valve group of the present invention;

[0034] Figure 7 The invention discloses a processing principle diagram of a valve body fastening hexagonal and arc-shaped groove of an integrated valve group for taking pressure from an orifice plate of an industrial pipeline.

[0035] The reference numerals shown in the figure are: 1-handle, 2-upper valve cover dust cap, 3-tightening nut, 4-valve stem, 5-valve body, 6-valve body fixing bolt, 7-arc groove, 8-valve body sealing gasket, 9-stuffing box clamping cover, 10-high elastic gasket, 11-stuffing box, 12-upper sealing surface, 13-lower sealing surface, 14-upper sealing valve core, 15-lower sealing valve core, 16-pressure taking flange, 17-pressure taking main valve, 18-pressure taking auxiliary valve, 19-external pressure taking hole, 20-pressure taking short joint, 21-internal pressure taking hole, 22-orifice plate, 23-pressure taking flange fastener, 24-through needle, 25-valve body fastening hexagon. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] As attached Figure 1 To the attached Figure 7 As shown, the composition, assembly and function description of an industrial pipeline orifice plate pressure-taking integrated valve group of the present invention.

[0038] Attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 It is a cross-sectional view, a top view and a side view of the orifice plate 22, the pressure flange 16 and the integrated valve group as a whole. The connection surface between the orifice plate 22 and the pressure flange 16 is the same as the classic orifice plate. The orifice plate 22 is manufactured in the same way as the orifice plate in the prior art. The structure of the pressure flange 16 in the present invention is based on the classic pressure flange and is partially strengthened at the pressure taking part. The principle can be referred to in the attached Figure 1 , Attachment Figure 3 and attached Figure 4 As shown, the pressure taking flange 16 is reinforced with two valve bodies, the pressure taking main valve 17 and the pressure taking auxiliary valve 18, and the pressure taking short joint 20 is installed on the external pressure taking hole 19. The installation position is referenced Figure 2Top view of the pressure-taking flange and the integrated valve group assembly. The pressure-taking main valve 17, the pressure-taking nipple 20, and the pressure-taking auxiliary valve 18 are arranged in sequence from the position close to the orifice plate along the pipeline direction from the inside to the outside on a plane. The valve body 5 of the pressure-taking main valve 17 can be installed along the radial direction of the pipeline cross section. If the valve body 5 is large or the pressure-taking method is angle connection, the valve body 5 can also be slightly inclined to the side facing away from the orifice plate. At this time, the pressure-taking flange 16 body can be partially processed into a slope surface to facilitate vertical screwing of the valve body 5 on the slope surface. The tapping position of the valve body fixing bolt 6 at the reinforced part has a net distance from other opening positions that is sufficient to not affect the structural strength of the flange. The net distance size can refer to the minimum wall thickness required by the manufacturing drawings of forgings and pipe fittings of corresponding pressure levels in ASME B16.11, GB / T 12459, GB / T 14383, etc., and it only needs to be not less than the wall thickness. The design principles for the net distance requirements of all other hole spacings are the same. The valve stem 4 of the pressure-taking main valve 17 is downwardly aligned with the inner pressure-taking hole 21, and the direction of the valve stem 4 is consistent with the rotation direction of the inner pressure-taking hole to form an angle valve sealing structure. The inner pressure-taking hole 21 is opened on the inner side of the pipeline, and the center position of the hole conforms to the calculation principle of the orifice plate as well as the classic orifice plate pressure-taking hole. The aperture of the inner pressure-taking hole 21 can be rotated according to the nominal diameter of the pipeline DN200 or above 8mm. When the pipeline is of small diameter or the orifice plate medium is clean and not easy to be blocked, the aperture can be appropriately reduced to facilitate the sealing of the lower sealing surface 13. The aperture is appropriately smaller, 3 to 8mm, in principle to ensure that the calculation of the standard orifice plate meets the standard. When the pressure-taking aperture is designed to be small or the medium fluid contains solid particles and is easy to block the pressure-taking port, the lower end of the valve stem 4 of the pressure-taking main valve 17 and the pressure-taking auxiliary valve 18 can be optimized to be designed as a special welding pass needle 24, and a mechanical cleaning method is used to ensure that the flow path is unobstructed. The functional description of the pass needle 24 is detailed in "Example 2". The relative position of the external pressure-taking hole 19 and the pressure-taking main valve 17 and the pressure-taking auxiliary valve 18 is referenced Figure 1 , Figure 2The opening of the external pressure-taking hole 19 can be radial or inclined at an angle to the pipe cross section. In principle, the external pressure-taking hole 19 is located between the main and auxiliary valve bodies and the internal opening is located between the lower sealing surface 13 and the upper sealing surface 12 of the pressure-taking auxiliary valve 18. The position of the pressure-taking nipple 20 does not affect the handle operation of the pressure-taking main valve 17 and the pressure-taking auxiliary valve 18. The external pressure-taking hole 19 is internally tapped with a tapered internal thread FNPT 1 / 2, with a tapping length of 25mm. Before assembling the valve body, screw in an external thread MNPT 1 / 2 pressure nipple 20, the material of the pressure nipple 20 must be consistent with the material of the pressure flange 16 and must be forged. The nipple is thickened and the exposed length of the nipple is at least 100-150mm. It is allowed to weld the pressure pipe to the connecting pipe fittings. After the nipple is screwed in, the root of the nipple is sealed with argon arc welding. It should be noted that the screwing in and welding of the nipple must be completed before installing the valve body and packing to avoid high temperature welding to damage the packing. The other side of the nipple can be processed according to the project requirements. The connection specifications, when the use of ferrules is allowed, can be directly processed into external threads for connecting external threaded ferrule terminal joints. When welding connection is required, it can be beveled or flat. The nipple can also be a different diameter nipple, directly welded to the pressure pipe or pipe clamp. When the processing lathe technology allows, the structure of the pressure nipple 20 can also be directly processed on the body, and the effect is better without welding points. Reference Figure 3 , Figure 4 Because the design of the external pressure-taking hole 19 makes the pressure-taking hole have no inverted U-bend, the valve group can be rotated at any angle during installation. When the handle of the orifice plate is sandwiched by the handwheel 1, the orifice plate handle should be processed higher than the main valve handwheel to facilitate pulling out. Figure 1 The inclination angle of the pressure-taking auxiliary valve 18 relative to the pipeline cross section is larger than that of the pressure-taking main valve 17. The position of the flow path opening in the valve that its valve stem 4 needs to align with is located between the lower sealing surface 13 and the upper sealing surface 12 of the pressure-taking main valve 17. When the inclination angle is too large and inconvenient to install, an inclined surface can be cut obliquely on the outer edge of the reinforced part of the pressure-taking flange 16 for installation. During processing, the length of the reinforced part and the height of the local protrusion can be flexibly calculated according to the diameter of the orifice plate and the size of the pressure-taking flange 16. The lengths of the two valve bodies and valve stems of the pressure-taking main valve 17 and the pressure-taking auxiliary valve 18 can be designed to be of different sizes. The design principles are easy to install, ensuring that the center of the internal pressure-taking hole 21 is at the standard calculated pressure-taking position on the inside of the pipeline, and ensuring strength according to the pressure level. The range of the reinforced part of the pressure-taking flange 16 does not need to be too large to reduce the weight of the orifice plate. The valve body can meet the strength requirements after installation, but it needs to be combined with the rotation position of the fastener 23 of the pressure-taking flange 16, refer to Figure 3 , Figure 4The reinforced part includes at least two fastening bolts and a pressure-taking hole in the middle of the bolt hole. It should be noted that these two bolts should be designed as extended bolts according to the reinforced length. The design of other bolts is consistent with the classic orifice plate. The pressure-taking flow path passes through the center of the two bolts. The bottom lower sealing surface 13 of the valve body 5 of the pressure-taking main valve 17 is in principle located around the outer diameter of the classic pressure-taking flange. This design can ensure that the size of the part below the valve body is not less than the size of the classic pressure-taking flange, ensuring the strength of the pressure-taking orifice plate. Reference Figure 1 Because the length of the local reinforced part is longer than the original classic orifice plate, the length of the overall orifice plate will be longer than the original classic orifice plate. However, during manufacturing, it is necessary to ensure that the inner wall of the pressure flange 16 is consistent with the inner wall size of the pipeline. The two sides of the pressure flange 16 are welded structures, which are the same as the processing surface of the original classic orifice plate connected to the pipeline. The part from the reinforced part to the part welded with the pipeline is a transition section, and its processing thickness is not less than the pipeline thickness to ensure strength. You can choose the processing method by yourself.

[0039] Functional description of valve body and internal accessories:

[0040] The structure principle of the pressure taking main valve 17 and the pressure taking auxiliary valve 18 is the same, but the manufacturing dimensions can be different. For detailed structure, refer to Figure 5 Note: The valve body material should be consistent with the flange material to facilitate welding the valve body if necessary under high pressure. The reinforced part of the pressure flange 16 is tapped according to the outer diameter of the valve body 5. The basic structure of the valve body 5 is annular, with threaded outer part at the bottom. The thread is a straight thread. M thread is recommended, and the outer diameter of the thread matches the outer diameter of the valve body.

[0041] The special feature of the present invention is that the valve body is installed in a straight thread plus a sealing gasket 8 plus a valve body fixing bolt 6 fixing structure, which is more strengthened than the simple thread sealing or simple bolting structure of the prior art, and can effectively prevent the high pressure from damaging the threads outside the valve body and blowing the valve body out. The material of the sealing gasket 8 can be determined according to the medium corrosion conditions and temperature and pressure. Generally, it can be a polytetrafluoro gasket when the medium temperature is 0 to 160 degrees, and it can be a flexible graphite gasket when the temperature is higher than 160 degrees or lower than 0 degrees. Figure 7 The valve body is designed with a valve body fastening hexagon 25 on the top of the valve body for easy tightening with a wrench. Because the entire valve body 5 is tightened, the final position of the valve body after tightening the gasket is uncertain, and it is not necessarily the case that the bolt hole position of the valve body fixing bolt 6 is aligned with the tapping position of the body. Therefore, the present invention designs a special arc-shaped slot 7 to match the bolt screwing into the tapping position. Please refer to the arc-shaped slot function description below. The valve body fixing bolt 6 is designed as a single-head hexagonal bolt, and the bolt material can be selected from high-strength alloy steel according to the relevant standard reference temperature and pressure. The arc-shaped slot 7 is processed on the valve body fastening hexagon 25, and the hexagon should be appropriately thickened during processing. The structural design of the arc-shaped slot 7 can enable the valve body to have the fastening ability of both threaded and bolted structures, and more effectively prevent the valve body from being blown out as a whole by high-pressure media.

[0042] refer to Figure 5 , the inside of the valve body 5 also needs to be threaded, and the thread is also a straight thread, which can be screwed into the clamping nut 3 to clamp the stuffing box 11. The material of the clamping nut 3 is consistent with that of the valve body 5 to ensure the same thermal expansion coefficient and good sealing. The valve cover dust cap 2 is equipped on the outside to prevent dust from clogging the exposed thread on the valve stem 4. The material of the upper valve cover dust cap can be stainless steel. The design can refer to the mature technology of existing products. The center of the clamping nut 3 is tapped and the upper part of the valve stem is threaded. The thread sizes are the same as the standard straight threads. Its structure can refer to the mature technology of the existing integrated valve group for processing. In order to reduce the wear of the packing, the present invention takes into account that the maximum pressure taking hole is only 8mm, and the valve stem can be regarded as fully open when it is 10mm away from the sealing surface. The spacing between the upper sealing valve core 14 and the lower sealing valve core 15 can be designed according to this distance.

[0043] The smaller the valve body, the better the high pressure resistance. Because of the unique integral forging processing structure of the present invention, there is no welding at the inlet and outlet of the valve flow path, which can avoid welding to the greatest extent, reduce construction procedures, and also reduce leakage caused by corrosion of welding points. The valve body is small, and the pressure tapping hole is directly used as the valve body flow path, the flow path is simpler, the valve core pressure bearing area is small, and it is easier to withstand high pressure.

[0044] Description of the fastening function of the arc slot:

[0045] refer to Figure 7 The function of the arc groove 7 is the special feature of the present invention. After the valve body is screwed into the pressure-taking flange through the outer thread of the valve body and the valve body seal is formed, the valve body fixing bolt 6 can still be allowed to double-tighten the valve body. The inner and outer sides of the arc groove 7 are concentric circles of different radii. The radius difference is that the groove width is just slightly larger than the outer diameter of the bolt. The groove allows the deviation of the valve body fixing bolt 6 and the bolt screw-in position to be matched within a certain range. The arc groove 7 is designed to be at least 2. The bolt tapping position should be arranged at the center arc position of the groove and be symmetrical relative to the center of the valve body 5 screw-in hole. It can be designed to be 2 for medium and low pressure occasions with a pipeline pressure level of up to 600 pounds. In high-pressure occasions, when the pipeline pressure level is 900 pounds and above, the arc groove 7 is designed to be symmetrical with 4 valve body fixing bolts 6, and the valve body is reinforced with 4 valve body fixing bolts 6.

[0046] Function description of valve stem bidirectional sealing:

[0047] The design of the valve stem 4 is a special feature of the present invention and can be referred to Figure 5, two valve cores are integrally processed at the lower part of the valve stem 4, and a bidirectional sealing function is designed. The material can take into account the thermal expansion rate of the flange base material and select high-hardness alloy steel. The design can be optimized to be a two-stage valve stem of current mature technology. The lower valve stem and the upper valve stem are movably connected in the cavity of the clamping nut 3. Since the movement of the upper valve stem is an angular stroke plus a linear stroke, when it is designed as a two-stage valve stem, the lower valve stem is only a linear stroke movement, and the wear of the valve core and the sealing surface, the valve stem and the packing is minimized, which is conducive to preventing internal and external leakage of the valve. The upper sealing valve core 14 and the lower sealing valve core 15 are integrally processed on the valve stem 4, both of which are cones. The upper sealing valve core 14 and the upper sealing surface 12 are designed as a mutually matching sealing combination. The upper sealing surface 12 is processed with a rotating hole at the bottom center of the valve body 5, and its chamfer matches the cone angle of the upper sealing valve core 14, in order to achieve the best sealing effect. The lower sealing valve core 15 and the lower sealing surface 13 are designed to be a sealing combination that matches each other, and the chamfer of the lower sealing surface 13 matches the cone angle of the lower sealing valve core 15 for sealing. The external leakage of the valve mostly occurs at the packing part. When the medium is high pressure, after the valve stem moves many times, the medium corrodes the valve stem or the packing may leak at the worn part. The design function of the valve group is that when the pressure is started, the handle 1 is turned to lift the valve stem 4 by about 10 mm, so that the valve is in the fully open position, so that the upper sealing surface 12 is sealed by the upper sealing valve core 14. The normal pressure taking time is very long. At this time, the packing and the valve stem above the upper sealing valve core 14 are always in a state of not being pressurized and not in contact with liquid, and no corrosion and leakage will occur. When the valve is closed, the handle 1 is rotated for a short time to make the lower sealing valve core 15 press the lower sealing surface 13 to seal, and then the medium is cut off. The packing is still not pressurized, and is only pressurized for a few seconds during the rotation process. Therefore, the present invention can basically achieve no external leakage of the valve body during the whole process. From the inner pressure taking hole 21 to the lower part of the valve body, it is a closed structure. The valve body is a threaded and gasketed sealing structure. The valve body has no movable parts and is not easy to leak. Although the valve stem is a movable part, the two-way seal ensures the sealing performance. Therefore, the present invention is particularly suitable for occasions with toxic media to prevent external leakage of the valve body. Because of the special structure of the present invention, the valve core and the valve stem are processed in one piece, the diameter of the valve core is larger than the valve stem, and the valve stem cannot be blown out of the valve body by high pressure. The design is an intrinsically safe structure. When the upper seal is formed normally, the higher the pressure, the tighter the upper sealing surface is pressed, and the better the sealing effect. When assembling, the valve stem 4 needs to be inserted from the lower part of the valve body in reverse in advance, and screwed into the body of the pressure flange 16 at the same time as the valve body, and then the stuffing box 11, high elastic gasket 10, stuffing box clamping cover 9 are assembled, and finally the clamping nut 3 is tightened, and finally the handle 1 is assembled.

[0048] Stuffing box function description:

[0049] See the assembly drawing of stuffing box 11 for details. Figure 6As shown, the stuffing box can be designed to be easy to seal based on the current mature technology. It is recommended to use materials with good deformation or low hardness. The shape can be designed to be a "V"-shaped packing ring with the current mature technology. The upper part of the high-elasticity gasket 10 is pressed by the stuffing box clamping cover 9, and the upper part of the stuffing box clamping cover 9 is tightened by the clamping nut 3. The high-elasticity gasket 10 squeezes the packing and deforms to seal the valve stem. The greater the clamping force, the better the sealing effect. Although the friction force is large, because the valve stem 4 is very thin and cooperates with the appropriate handle 1, it does not affect the valve action.

[0050] Operating temperature instructions:

[0051] The standard type of the present invention is not recommended for use in media with temperatures exceeding 300 degrees and below -20 degrees, because under ultra-high or ultra-low temperatures, it is impossible to design an extended neck structure for the valve body, and extreme temperatures affect the seal between the valve stem and the packing and the seal of the valve core sealing surface.

[0052] Heat Tracing Instructions:

[0053] Due to the integrated design of the present invention, it is easy to maintain the temperature in the overall structure without heating. The heating can be implemented from the pressure taking nipple 20 to the downstream of the pressure leading pipe, which is more convenient.

[0054] Instructions for use of pressure:

[0055] When used in high-pressure pipelines with a pressure rating of 2500 pounds, the design can be optimized into a special type, see the following "Example 1" for details.

[0056] Valve operation sequence description:

[0057] When the pressure-taking valve group is put into use, first open the pressure-taking main valve 17, and then open the pressure-taking auxiliary valve 18. Once opened, ensure that the upper sealing valve core 14 is screwed upward to the sealing position of the upper sealing surface 12 as soon as possible. It is recommended that the pressure-taking main valve 17 be placed in the upper sealing position and not operated as much as possible to reduce the frequency of action to maximize its cut-off function in critical situations. When short-term cut-off or short-term maintenance is required, the pressure-taking auxiliary valve and the cut-off valve on the pressure-leading pipeline can be cut off. In the special case of cut-off failure, the pressure-taking main valve 17 is actuated to keep it in the upper sealing state all the time, prevent the medium from penetrating into the packing and corroding the threads and valve stem, reduce the action of the pressure-taking main valve, and reduce the wear of the packing and valve core, so as to ensure its cut-off function at critical moments.

[0058] Example 1

[0059] When the ultra-high pressure is 2500 pounds, or the medium is highly toxic, or the project requires special welding seals, the optimized design can be to directly screw the valve body in and then seal it. After screwing in the valve body and valve stem, assemble the stuffing box 11 and before tightening the clamping nut 3, directly use argon arc welding to seal the periphery of the valve body to ensure that there is no leakage outside the valve body. Then install the stuffing box assembly, tighten the clamping nut 3, and compress the stuffing box 11 to seal at the valve stem. Because the two-way sealing design minimizes the probability of leakage, even in the most extreme case, the medium breaks through the upper sealing surface, it can only be bubbles. It is difficult to form high pressure to break through the stuffing box with a leakage of the same level. In extreme cases, the second sealing surface packing is broken through at the same time and leakage occurs. The leakage will be even smaller and it is difficult to form high pressure in the upper cavity of the clamping nut 3 and the valve stem 4. The gas needs to continue to break through the thread seal of the clamping nut 3 or the thread seal of the valve stem 4 to cause external leakage. Because all components are miniaturized in design, the leakage surface is very small, the pressure-bearing area is also very small, and the thrust formed by the pressure difference is also very small. The probability of breaking through the third seal is small. During regular maintenance, the clamping nut 3 can be unscrewed and the packing can be replaced in time to ensure a tight seal.

[0060] Example 2

[0061] If the medium is a very clean high-pressure gas, when measuring normally, the fluid in the pressure-taking pipeline does not flow, and the pressure-taking auxiliary valve 18 is not easy to be blocked. The design can be optimized to make the flow path hole aligned with the valve stem of the pressure-taking auxiliary valve 18 smaller. When turning the hole, use a small-diameter turner or laser drilling to turn it into the valve cavity between the upper sealing surface 12 and the lower sealing surface 13 of the pressure-taking main valve 17. The through hole is about 5mm, and the hole diameter is suitable for not easily blocking the flow path according to the medium situation. At this time, the lower part of the valve stem can be welded with a through needle 24, and the through needle 24 is The optional design can be used when the pressure-taking auxiliary valve 18 selects a small-diameter flow path. The length of the pass needle 24 is when the valve is closed, just enough to force the solid particles in the flow path into a larger cavity. The outer diameter of the pass needle 24 can be designed to be 1-2 mm. The pass needle 24 can be designed to be a conical spiral, and the spiral radius gradually decreases from the valve core downward. The spiral angle is designed to be greater than 45 degrees. This design structure has the best effect of cleaning the flow path during the rotation movement, and can also prevent the solid particles from hardening at the spiral. Once the flow path of the pressure-taking auxiliary valve 18 is blocked, the valve stem 4 of the pressure-taking auxiliary valve 18 can be moved once with a full stroke. When the valve stem moves up and down, the flow path is cleaned by the pass needle 24. Because the seal adopts the structural type of an angle valve, the pass needle 24 does not affect the sealing function of the valve core. If there is foreign matter, when the valve stem moves up and down, the pass needle pushes the foreign matter into the valve cavity of the pressure-taking main valve 17. When the medium may contain unexpected small solid particles or catalyst powder that may easily block the flow path of the pressure taking main valve 17, the design can be optimized to design the bottom ends of the valve stems of the pressure taking main valve 17 and the pressure taking auxiliary valve 18 with a pass needle 24. Figure 1As long as the valve stem moves, the flow path will definitely be unobstructed. This method is better than using a hand pump in the pressure-inducing pipe to reversely clean the flow path with high-pressure media. It does not cause media contamination and the principle is simple and reliable.

Claims

1. An integrated valve group for taking pressure from an orifice plate of an industrial pipeline, characterized in that: It comprises a pressure-taking flange and a main pressure valve and a secondary pressure valve installed on the pressure-taking flange, wherein the main pressure valve is the first sealing valve for cutting off the pressure-taking flow path, and the secondary pressure valve is the second sealing valve for cutting off the pressure-taking flow path, and the flow path designs of the two valves are both angle valve structures with bottom sealing; the bottom flow path of the main pressure valve is directly connected to the pressure-taking hole of the pressure-taking orifice plate, and the bottom of the secondary pressure valve is opened in the bottom valve body chamber of the main pressure valve, and after the main valve is closed and cut off, the pressure flow path is completely cut off, and after the secondary valve is cut off, the pressure flow path is also completely cut off, and the main valve and the secondary valve form a series double cut-off in the pressure flow path; the pressure flange, the main pressure valve and the secondary pressure valve form an integrated structure.

2. The orifice plate pressure-taking integrated valve group according to claim 1, characterized in that: An external pressure-taking hole is arranged on the pressure-taking flange, and a pressure-taking nipple is installed on the external pressure-taking hole.

3. The orifice plate pressure-taking integrated valve group according to claim 1, characterized in that: The structures of the pressure taking main valve and the pressure taking auxiliary valve are the same, and are composed of a valve body, a valve body sealing gasket, a valve body fastening hexagon, a valve body fixing bolt, a clamping nut, a stuffing box clamping cover, a high-elastic gasket, a stuffing box, a valve stem, an upper sealing valve core, a lower sealing valve core, and a pass needle.

4. The orifice plate pressure-taking integrated valve group according to claim 3, characterized in that: The valve body, valve body fastening hexagon, valve body sealing gasket and valve body fixing bolts form a fastening structure of the valve body. After the valve body is screwed into the pressure-taking flange to compress the valve body sealing gasket, the valve body fixing bolts can still be used to continue to double-fasten the valve body.

5. The orifice plate pressure-taking integrated valve group according to claim 3, characterized in that: The clamping nut, stuffing box clamping cover, high-elastic gasket, stuffing box, valve stem, upper sealing valve core, lower sealing valve core and pass needle constitute the sealing mechanism of the valve core assembly. The clamping nut is screwed into the valve body through threads to compress the stuffing box clamping cover, high-elastic gasket and stuffing box. The stuffing box is deformed to form a seal around the valve stem, so that the valve stem will not leak outside the gap between the valve stem and the clamping nut when it moves up and down.

6. The orifice plate pressure-taking integrated valve group according to claim 3, characterized in that: An upper sealing valve core and a lower sealing valve core are arranged on the valve stem to form a two-way seal on the flow path chamber at the bottom of the valve body, so as to prevent the stuffing box from being pressurized and leaking for a long time when the flow path is opened.

7. The orifice plate pressure-taking integrated valve group according to claim 3, characterized in that: A pass needle is arranged under the valve stem.

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