Method for field installation of a large 304L tubular equipment closure cylinder

Abstract

The application provides a large 304L tubular device closing cylinder field installation method, a first long neck butt flange is arranged on a closing cylinder port, and a second long neck butt flange is arranged on a front cylinder or a rear cylinder; the installation of the front cylinder and the rear cylinder is completed, and the second long neck butt flange is synchronously installed; a plurality of groups of first vertical distances between two first end faces are measured along the circumferences of the first end faces of the front cylinder and the rear cylinder, an average value D1 of the first vertical distances is calculated, a plurality of groups of second vertical distances between two second end faces are measured along the circumferences of the second end faces of the front cylinder and the rear cylinder, an average value D2 of the second vertical distances is calculated, the length of the whole component formed by the closing cylinder and the first long neck butt flange is adjusted to D1-4~D1-8mm in the axial direction and at the position corresponding to the first end face, and the length of the whole component is adjusted to D2-4~D2-8mm in the axial direction and at the position corresponding to the second end face; the hydraulic nut is tightened; and the closing weld is welded. The application solves the problem of difficult installation of the closing cylinder and improves the installation precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pressure vessels, in particular to a large 304L tubular device closing cylinder field installation method. BACKGROUND

[0002] A certain large tubular device is a horizontal structure with a cross shape, the main material is 304L, the long axis direction is 80 meters long, and the short axis direction is 30 meters long. Due to the large size, it is difficult to transport, so the construction site is used for manufacturing and installation. The device has a large span and high installation precision, so a compensation section (i.e. closing cylinder) is arranged in the long axis and short axis direction of the device, and finally installed to ensure the overall size of the device and the accurate installation of the important cylinder.

[0003] In order to realize smooth installation, sufficient installation space is reserved on site, so that the gap between the front and rear port closing welds of the closing cylinder is large after installation, and a large shrinkage and deformation will occur during welding, especially for 304L austenitic stainless steel, which will cause the elevation and axis of the cylinder connected with the front and rear of the closing cylinder to change, often exceeding the deviation range. In order to ensure the installation precision of the device, the front and rear ports of the closing cylinder are connected with the cylinder by flanges, and in order to ensure the sealing performance between the flanges, the installation space cannot be reserved too large on site, which is convenient and feasible for small closing cylinders, but it is difficult to install large closing cylinders in the case of small installation space.

[0004] Therefore, it is necessary to develop a large 304L tubular device closing cylinder field installation method to solve the above problems. SUMMARY

[0005] The present application provides a large 304L tubular device closing cylinder field installation method, which aims to solve the problems of difficult installation and reduced installation precision of the existing large 304L cross-shaped tubular device closing cylinder.

[0006] The technical scheme of the present application is:

[0007] A large 304L tubular device closing cylinder field installation method, comprising the following steps:

[0008] S1, a first long neck butt welding flange is arranged on the front port or rear port of the closing cylinder, and a second long neck butt welding flange matched with the first long neck butt welding flange is arranged on the front cylinder or rear cylinder connected with the closing cylinder;

[0009] S2, complete all installation work of the front cylinder or the rear cylinder, and install the second long neck butt welding flange and the front cylinder or the rear cylinder synchronously;

[0010] S3, find out the two interface end faces closest to each other on the front barrel and the rear barrel, divide each interface end face into a first end face and a second end face with the lowest point and the highest point on each interface end face as the demarcation points, and the first end face and the second end face together enclose the interface end face; measure a plurality of groups of first vertical distances between the two first end faces along the circumferential side edges of the two first end faces at uniform intervals, and calculate the average value D1 of the plurality of groups of first vertical distances; measure a plurality of groups of second vertical distances between the two second end faces along the circumferential side edges of the two second end faces at uniform intervals, and calculate the average value D2 of the plurality of groups of second vertical distances;

[0011] S4, the folding barrel and the first long neck butt flange are made into an integral member, the length of the integral member in the axial direction and corresponding to the first end face is adjusted to D1-4~D1-8mm, and the length of the integral member in the axial direction and corresponding to the second end face is adjusted to D2-4~D2-8mm;

[0012] S5, the integral member is installed by falling from top to bottom from the gap between the front barrel and the rear barrel, and is embedded into the gap between the front barrel and the rear barrel; stud bolts are installed in the first bolt hole and the second bolt hole corresponding to the first long neck butt flange and the second long neck butt flange, and the hydraulic nut is used for initial tightening to adjust the assembly quality of the folding barrel and the front barrel or the rear barrel.

[0013] S6, the hydraulic nut is completed by using a hydraulic bolt stretcher, and the folding weld between the folding barrel and the front barrel or the rear barrel is welded: first, surfacing is performed on the bevel using tungsten inert gas welding until the gap between the bevels is 2~4mm, then backing welding is performed using tungsten inert gas welding, and finally multi-layer multi-pass welding is performed using shielded metal arc welding.

[0014] As a technical solution of the present application, the first long neck butt flange is uniformly and spacedly provided with a plurality of first bolt holes in the circumferential direction, and is provided with two circles of first sealing grooves in the circumferential direction, and the two circles of first sealing grooves are located on the inner side of the first bolt holes; the second long neck butt flange is uniformly and spacedly provided with a plurality of second bolt holes in the circumferential direction, and is provided with two circles of second sealing grooves in the circumferential direction, and the two circles of second sealing grooves are located on the inner side of the second bolt holes.

[0015] As a technical scheme of the present application, the first bolt hole on the first long-neck butt welded flange is first prepared, then the first long-neck butt welded flange is assembled and welded with the folded cylinder, then two circles of first sealing grooves and first flange faces on the first long-neck butt welded flange are machined, and finally the whole assembly is integrally installed.

[0016] As a technical scheme of the present application, the second bolt hole on the second long-neck butt welded flange is first prepared, then the second long-neck butt welded flange is assembled and welded with the front cylinder or the rear cylinder, and then two circles of second sealing grooves and second flange faces on the second long-neck butt welded flange are machined.

[0017] As a technical scheme of the present application, before the whole assembly is installed, a Vanse sealing element is installed in the second long-neck butt welded flange; when the whole assembly composed of the folded cylinder and the first long-neck butt welded flange is installed, a flexible thin object is inserted between the first flange face of the first long-neck butt welded flange and the second flange face of the second long-neck butt welded flange, and the flexible thin object is removed after installation is completed.

[0018] As a technical scheme of the present application, before the folded weld seam between the folded cylinder and the front cylinder or the rear cylinder is welded, the front cylinder and the rear cylinder are fixed to the ground using a temporary tool; when the folded weld seam between the folded cylinder and the front cylinder or the rear cylinder is welded, welding is stopped after each weld seam is welded, and welding is continued after the weld seam cools to room temperature, and water cooling measures are taken.

[0019] As a technical scheme of the present application, when the folded weld seam between the folded cylinder and the front cylinder or the rear cylinder is welded, a 0.03mm feeler gauge is used to measure the gap between the first flange face of the first long-neck butt welded flange and the second flange face of the second long-neck butt welded flange; if the gap is greater than 0.03mm, welding is stopped and the hydraulic nut is tightened again.

[0020] The present application has the following beneficial effects:

[0021] The application provides a large 304L tubular equipment closing cylinder field installation method, which is characterized in that: a first long neck butt welding flange is arranged at one end of the closing cylinder for flange connection, and the other end is welded, so that the welding amount is reduced, welding deformation is effectively reduced, installation precision of the equipment is ensured, and the sealing performance of the flange connection is good; the installation space is effectively measured before the closing cylinder is installed, and the length of the closing cylinder in the axial direction is adjusted in different regions, so that the installation difficulty is greatly reduced without increasing the gap between the closing weld seam groups; in addition, the gap between the closing weld seams is large, and the gap is welded after surfacing, and the hydraulic bolt tensioner is used to fasten the bolt and the Vanse sealing element is used, so that the welding deformation is effectively reduced, the flange sealing performance is ensured, and the final overall precision of the equipment is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0023] Figure 1 The front cylinder and the rear cylinder installation completion schematic diagram provided by the embodiments of the application;

[0024] Figure 2 The closing cylinder manufacturing process schematic diagram provided by the embodiments of the application;

[0025] Figure 3 The closing cylinder installation process schematic diagram provided by the embodiments of the application.

[0026] Figure legend: 1-front cylinder; 2-first long neck butt welding flange; 3-rear cylinder; 4-closing cylinder; 5-second long neck butt welding flange; 6-first end face; 7-second end face. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the following will combine the drawings in the embodiments of the application to clearly and completely describe the technical solutions in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, not all the embodiments. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents selected embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the application.

[0029] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0030] In the description of the application, it should be noted that the terms "upper", "lower", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, and are merely for the convenience of describing the application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0031] In addition, in the present application, unless otherwise explicitly specified and limited, the first feature above or below the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature therebetween. Moreover, the first feature above, above and above the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature below, below and below the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0032] In addition, the terms "horizontal", "vertical", and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0033] In the description of the application, it should also be noted that unless otherwise explicitly specified and limited, the terms "provided", "connected", "connected" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements inside. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] Embodiment:

[0035] Please refer to Figure 1 , for referenceFigures 2-3 The embodiment provides a large 304L tubular device closing cylinder field installation method, a rear end of the closing cylinder 4 is provided with a first long neck butt flange 2, a front end of the rear cylinder 3 is provided with a second long neck butt flange 5; the first long neck butt flange 2 is uniformly and spacedly provided with a plurality of first bolt holes along the circumference, and two circles of first sealing grooves are arranged on the circumference of the first long neck butt flange 2, and the two circles of first sealing grooves are located on the inner side of the first bolt holes; the second long neck butt flange 5 is uniformly and spacedly provided with a plurality of second bolt holes along the circumference, and two circles of second sealing grooves are arranged on the circumference of the second long neck butt flange 5, and the two circles of second sealing grooves are located on the inner side of the second bolt holes. The front end of the closing cylinder 4 is welded and connected with the rear end of the front cylinder 1, and the first long neck butt flange 2 of the closing cylinder 4 is connected with the second long neck butt flange 5 of the rear cylinder 3 through a double-headed stud and a hydraulic nut.

[0036] If the front end and the rear end of the closing cylinder 4 are all welded and connected with the front cylinder 1 and the rear cylinder 3, the welding workload is large, welding deformation is large, the elevation and the axis of the front cylinder 1 and the rear cylinder 3 are changed, and the overall installation precision of the tubular device is often out of the deviation range, so that the overall installation precision of the tubular device is unqualified. If the front end and the rear end of the closing cylinder 4 are all flange connected with the front cylinder 1 and the rear cylinder 3, in order to ensure the sealing performance between the flanges, a large installation space cannot be reserved on site, so that the large closing cylinder 4 is difficult to install and is not convenient to be embedded between the front cylinder 1 and the rear cylinder 3. Therefore, one end of the closing cylinder 4 is arranged as a welded joint, and the other end is arranged as a flange joint, so that the welding workload is reduced, the welding deformation is reduced, the installation of the closing cylinder 4 is facilitated, and the sealing performance of the flanges is ensured.

[0037] As shown in Figure 1 , the remaining cylinders (including the front cylinder 1 and the rear cylinder 3) of the large 304L tubular device except the closing cylinder 4 are all installed, before installation, the rear cylinder 3 and the second long neck butt flange 5 are made as an integral component and then installed. The manufacturing process of the rear cylinder 3 and the second long neck butt flange 5 is as follows: the second long neck butt flange 5 is first made to have the second bolt hole, then is assembled and welded with the rear cylinder 3, and then the two circles of second sealing grooves and the flange face of the second long neck butt flange 5 are processed.

[0038] When the second long neck butt flange 5 is welded with the rear cylinder 3, welding deformation exists, if the second sealing groove and the flange face of the second long neck butt flange 5 are processed first and then the second long neck butt flange 5 is assembled and welded with the rear cylinder 3, although the manufacturing efficiency is high, the flange face and the second sealing groove will be deformed and need to be reprocessed. The inner diameter of the second bolt hole is usually larger than the outer diameter of the double-headed stud, and the position deviation of the second bolt hole in the welding process does not affect the installation of the double-headed stud in the later period, so the second bolt hole can be made first.

[0039] The two interface end faces closest to each other on the front cylinder body 1 and the rear cylinder body 3 are found on the installation site, each interface end face is divided into a first end face 6 and a second end face 7 with the lowest point and the highest point on each interface end face as the interface points, and the first end face 6 and the second end face 7 together enclose the interface end face; the first vertical distance between the two first end faces 6 is measured at evenly spaced intervals along the circumferential side of the two first end faces 6, and the average value D1 of the multiple sets of first vertical distances is calculated; the second vertical distance between the two second end faces 7 is measured at evenly spaced intervals along the circumferential side of the two second end faces 7, and the average value D2 of the multiple sets of second vertical distances is calculated.

[0040] As shown in Figure 2 , the folding cylinder body 4 and the first long-neck butt flange 2 are made into an integral component: first, the first bolt hole of the first long-neck butt flange 2 is made, then the first long-neck butt flange 2 is assembled and welded with the folding cylinder body 4, and finally the first two-circle sealing groove and the flange face of the first long-neck butt flange 2 are processed. The length of the integral component formed by the folding cylinder body 4 and the first long-neck butt flange 2 in the axial direction is measured, the length of the integral component in the axial direction and corresponding to the first end face 6 is cut to D1-4~D1-8mm, and the length of the integral component in the axial direction and corresponding to the second end face 7 is cut to D2-4~D2-8mm.

[0041] Since the folding cylinder body 4 is gradually inserted into the front cylinder body 1 and the rear cylinder body 3 from top to bottom during installation, it is necessary to measure multiple sets of first vertical distances and second vertical distances between the front cylinder body 1 and the rear cylinder body 3, and to adjust the length of the folding cylinder body 4 in the axial direction according to the measured multiple sets of first vertical distances and multiple sets of second vertical distances. To achieve smooth installation of the folding cylinder body 4, the length of the folding cylinder body 4 in the axial direction should be less than the minimum value of the multiple sets of distances, but this will cause the welding gap of the folding weld to be too large in many positions, resulting in excessive welding shrinkage and deformation. Therefore, the multiple sets of distances are divided into two parts according to the different positions measured, and the average values are calculated respectively, and the length of the folding cylinder body 4 in the axial direction corresponding to the two different positions is adjusted accordingly. If the length of the folding cylinder body 4 in the axial direction is directly adjusted according to the average value of the multiple sets of distances, the folding cylinder body 4 may be stuck in the front cylinder body 1 and the rear cylinder body 3 during installation, so the length of the folding cylinder body 4 in the axial direction is adjusted by reducing 4~8mm according to the average value of the multiple sets of first vertical distances and second vertical distances, which can facilitate the installation of the folding cylinder body 4 and also does not increase the welding gap of the folding weld.

[0042] The Vanse seal is installed in the second long-neck butt flange 5, and then the integral component formed by the folding cylinder body 4 and the first long-neck butt flange 2 is installed in position from top to bottom of the front cylinder body 1 and the rear cylinder body 3, and is inserted between the front cylinder body 1 and the rear cylinder body 3, as shown in Figure 3As shown. When installing the closing cylinder 4, flexible thin material is inserted between the flange faces of the first long neck butt flange 2 and the second long neck butt flange 5, and the flexible thin material is removed after installation is completed, to protect the flange faces. Double-headed studs are installed on the first bolt hole and the second bolt hole corresponding to the first long neck butt flange 2 and the second long neck butt flange 5, initial tightening is performed using hydraulic nuts, then the assembly quality of the closing cylinder 4 and the closure weld of the front cylinder 1 or the rear cylinder 3 is adjusted, and finally final tightening of the hydraulic nuts is completed using a hydraulic bolt stretcher.

[0043] Due to the inevitable presence of slight shrinkage during welding, two Vanse sealing elements are used for sealing, and the springs in the Vanse sealing elements can ensure the sealing performance of the flanges during shrinkage. At the same time, in order to prevent the tensile stress during welding from causing a decrease in sealing performance, a hydraulic bolt stretcher and a hydraulic nut with high compression force are used to tighten the flanges, further ensuring the sealing performance of the flanges.

[0044] Before welding the closing cylinder 4 and the front cylinder 1, a temporary tool is used to fix the front cylinder 1 and the rear cylinder 3 to the ground to prevent displacement of the front cylinder 1 and the rear cylinder 3 during welding and reduce installation precision. When welding, first use tungsten inert gas welding to build up welding on the bevel until the bevel gap is 2-4 mm, then use tungsten inert gas welding to perform backing welding, reduce the bevel gap through build-up welding, and greatly reduce welding shrinkage, and finally use stick arc welding to perform multi-layer and multi-pass welding. When welding the closure weld of the closing cylinder 4 and the front cylinder 1, stop welding after each pass, continue welding after the weld cools to room temperature, and take measures to spray water to further control welding shrinkage and deformation. At the same time, a 0.03 mm feeler gauge is used to measure the gap between the flange faces of the long neck butt flanges during welding. If the gap is greater than 0.03 mm, stop welding and tighten the hydraulic nuts again to ensure the sealing performance of the flange faces.

[0045] The above only describes preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of field erection of a large 304L tubular equipment closure cylinder, characterized in that, The method comprises the following steps: S1, a first long-neck butt flange is arranged on the front end or the rear end of a converging cylinder, and a second long-neck butt flange matched with the first long-neck butt flange is arranged on a front cylinder or a rear cylinder connected with the converging cylinder; S2, all installation work of the front cylinder or the rear cylinder is completed, and the second long-neck butt flange is synchronously installed with the front cylinder or the rear cylinder; S3, two closest boundary end faces arranged oppositely on the front cylinder and the rear cylinder are found out, each boundary end face is divided into a first end face and a second end face with the lowest point and the highest point on each boundary end face as the boundary points, and the first end face and the second end face jointly enclose the boundary end face; a plurality of groups of first vertical distances between the two first end faces are measured along the circumferential side edges of the two first end faces at uniform intervals, and the average value D1 of the plurality of groups of first vertical distances is calculated; a plurality of groups of second vertical distances between the two second end faces are measured along the circumferential side edges of the two second end faces at uniform intervals, and the average value D2 of the plurality of groups of second vertical distances is calculated; S4, the converging cylinder and the first long-neck butt flange are made into an integral component, the length of the integral component in the axial direction and at the position corresponding to the first end face is adjusted to D1-4~D1-8 mm, and the length of the integral component in the axial direction and at the position corresponding to the second end face is adjusted to D2-4~D2-8 mm; S5, the integral component is installed by falling from top to bottom from the gap between the front cylinder and the rear cylinder and is embedded into the gap between the front cylinder and the rear cylinder; stud bolts are installed in the first bolt hole and the second bolt hole corresponding to the first long-neck butt flange and the second long-neck butt flange, and the hydraulic nut is used for initial tightening to adjust the assembly quality of the converging cylinder and the front cylinder or the rear cylinder; S6, the hydraulic nut is finally tightened by using a hydraulic bolt stretcher, and the converging weld between the converging cylinder and the front cylinder or the rear cylinder is welded; first, tungsten inert gas welding is used to perform surfacing on the bevel until the gap between the bevels is 2~4 mm, then tungsten inert gas welding is used to perform backing welding, and finally, multi-layer multi-pass welding is performed by using shielded metal arc welding.

2. The field installation method of large 304L tubular equipment closure cylinder according to claim 1, characterized in that, The first long-neck butt flange is uniformly and interval ly provided with a plurality of first bolt holes in the circumferential direction and is provided with two circles of first sealing grooves on the circumferential direction, and the two circles of first sealing grooves are located on the inner side of the first bolt holes; the second long-neck butt flange is uniformly and interval ly provided with a plurality of second bolt holes in the circumferential direction and is provided with two circles of second sealing grooves on the circumferential direction, and the two circles of second sealing grooves are located on the inner side of the second bolt holes.

3. The field installation method of large 304L tubular equipment closure cylinder according to claim 2, characterized in that, First, the first bolt hole on the first long-neck butt flange is prepared, then the first long-neck butt flange is assembled and welded with the converging cylinder, then the two circles of first sealing grooves and the first flange face on the first long-neck butt flange are processed, and finally, the integral component is made by the first long-neck butt flange and the converging cylinder for integral installation.

4. The field installation method of large 304L tubular equipment closure cylinder according to claim 2, characterized in that, The second bolt hole is first made on the second long-neck butt flange, then the second long-neck butt flange is assembled and welded with the front cylinder or the rear cylinder, and then two circles of second sealing grooves and a second flange face are processed on the second long-neck butt flange.

5. The field installation method of large 304L tubular equipment closure cylinder according to claim 1, characterized in that, Before the whole component is installed, a packing seal is installed in the second long-neck butt flange; when the whole component formed by the folded cylinder and the first long-neck butt flange is installed, a flexible thin object is inserted between the first flange face of the first long-neck butt flange and the second flange face of the second long-neck butt flange, and the flexible thin object is removed after the installation is completed.

6. The field installation method of large 304L tubular equipment closure cylinder according to claim 1, characterized in that, Before the folded weld between the folded cylinder and the front cylinder or the rear cylinder is welded, the front cylinder and the rear cylinder are fixed to the ground by using a temporary tool; when the folded weld between the folded cylinder and the front cylinder or the rear cylinder is welded, welding is stopped after each weld is welded, the welding is continued after the weld is cooled to room temperature, and water cooling measures are taken.

7. The field installation method of large 304L tubular equipment closure cylinder according to claim 1, characterized in that, When the folded weld between the folded cylinder and the front cylinder or the rear cylinder is welded, a gap between the first flange face of the first long-neck butt flange and the second flange face of the second long-neck butt flange is measured by using a 0.03 mm feeler gauge; if the gap is greater than 0.03 mm, the welding is stopped and the hydraulic nut is tightened again.

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