A method for manufacturing a large flange

Abstract

This invention discloses a method for manufacturing large flanges, comprising the following steps: S1, preparation of flange sections; S2, drawing a survey line at the flange production site; S3, arranging flange jigs along the survey outline; S4, marking the flange outer diameter outline on each flange jig; S5, assembling flanges on the flange jigs; S6, sealing the flange sections: inserting U-shaped clips with the snap-down end facing down onto the flange sections and welding the U-shaped clips to the flange jigs; S7, installing and fixing the flange sections with a star-shaped support: the star-shaped support includes a central support pier, multiple radially arranged horizontal support beams, and connecting plates. After welding the other end of the horizontal support beams to the U-shaped clips via the connecting plates, wedge-shaped metal blocks are inserted into the gap between the U-shaped clips and the flange sections to fix the flange sections; S8, preheating the flange section weld points; S9, welding the flange sections. Using this invention to manufacture large flanges not only improves manufacturing precision but also increases manufacturing efficiency.

Description

Technical Field

[0001] This invention relates to the field of flange manufacturing technology, specifically to a method for manufacturing large flanges. Background Technology

[0002] Large flanges refer to flanges that exceed the dimensions specified by relevant national authorities. They generally refer to flanges with a diameter of 10 μm or more. These products are all manufactured using a segmented welding process.

[0003] Currently, it is impossible to achieve both high manufacturing precision and high manufacturing efficiency in large flanges. To improve the manufacturing precision of large flanges, a relatively long manufacturing time is required, so the manufacturing efficiency is not high when the manufacturing precision is improved. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing large flanges, which not only improves manufacturing precision but also increases manufacturing efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for manufacturing a large flange includes the following steps:

[0007] Step S1, Flange section preparation: Draw flange drawings, divide the flange into multiple sections, and manufacture flange sections according to the requirements of the flange drawings;

[0008] Step S2: Draw the pattern line on the flange production site: Draw the pattern cross on the ground of the flange production site, mark the center of the flange at the intersection of the pattern cross and set the anchor point; draw the pattern outline of the flange inner diameter and outer diameter according to the center point, and draw the flange butt plate seam line and 16 equal division lines on the pattern outline.

[0009] Step S3: Arrange the flange jigs along the outline of the ground sample: Arrange the multiple flange jigs along the outline of the ground sample and fix the flange jigs on the ground of the flange production site.

[0010] Step S4: Draw the outer diameter outline of the flange on each flange jig: Use a total station to draw the outer diameter outline on the flange jig and set the flange punch points.

[0011] Step S5: Assemble the flange on the flange jig: Use an overhead crane to hoist the flange section onto the flange jig. One flange section corresponds to three flange jigs. The three flange jigs support the middle and both ends of the flange section respectively. Assemble the flange section according to the outer diameter outline, ground cross line, and flange butt plate seam line on the flange jig. After all flange sections are assembled, a circle is formed.

[0012] Step S6, Sealing the flange section: Insert the U-shaped clip with the jaws facing down onto the flange section and position it at the flange jig, and weld the U-shaped clip to the flange jig so that the flange section is inserted into the U-shaped clip, leaving a gap between the U-shaped clip and the flange section.

[0013] Step S7: Install the cross brace and fix the flange section: The cross brace includes a central support pier, multiple radially arranged horizontal support beams and connecting plates. Install the central support pier at the intersection of the ground cross lines. Connect one end of the horizontal support beam to the central support pier. Weld the other end of the horizontal support beam to the U-shaped clip through the connecting plate. Insert a wedge-shaped metal block into the gap between the U-shaped clip and the flange section to fix the flange section.

[0014] Step S8: Preheat the flange section weld points: Use electric heating elements to preheat the weld point area of ​​the flange section;

[0015] Step S9, Flange Section Welding: After preheating to the set temperature, begin welding the weld area of ​​the flange section. The specific welding method is as follows: S9.1, complete 1 / 3 of the bevel welding at the upper end of the flange section, then carbide the lower part of the flange section to remove white residue, and complete 1 / 3 of the bevel welding; after cooling, measure the flatness and roundness of the flange section; S9.2, based on the horizontal deviation value of the flatness in the first measurement data, determine the order of the upper and lower bevels during the second welding, and after completing 1 / 3 of the upper and lower bevel welding, cool... S9.3. Measure the flatness and roundness of the flange section; S9.4. Based on the horizontal deviation value of flatness in the second measurement data, determine the order of the upper and lower bevels during the third welding, and complete the welding of the remaining 1 / 3 of the upper and lower bevels. After the welding of this bevel is completed and cooled, measure the flatness and roundness of the flange section; S9.5. Based on the horizontal deviation value of flatness in the measurement data after the completion of the previous bevel welding, determine the order of the upper and lower bevels during the next bevel welding, until all upper and lower bevels are welded; S9.6. After all flange welding is completed, remove the U-shaped clamps and measure the flatness, roundness, and radius of the flange after overall welding.

[0016] Furthermore, in step S9, after all flange welding is completed, the outer diameter of the flange is 20160mm, the inner diameter is 19100mm, the width of the flange is 530mm, and the thickness of the flange is 230mm.

[0017] Furthermore, the flange is made of ASTM A694 material.

[0018] Furthermore, in step S1, the flange is divided into 8 sections with 8 butt joints, and the bevel angle of each butt joint is 55°.

[0019] Furthermore, in step S6, the length of the U-shaped card code is not less than 960mm, the height is not less than 450mm, and the thickness is not less than 30mm.

[0020] Furthermore, in step S9, the change in flatness is measured by pulling a steel wire, the change in curvature is measured by using an arc template, and the change in radius is measured by using a measuring tape.

[0021] Furthermore, in step S9, when the welding is discontinuous, the weld needs to be slowly cooled and kept warm after welding. During the welding process, a dedicated person must monitor the heating temperature and the holding temperature.

[0022] Furthermore, in step S8, preheating is performed using an electric heating element equipped with a thermocouple.

[0023] Furthermore, in step S9, the welding method used is WPS-950 Oxygen Dioxide Welding.

[0024] Furthermore, in step S9, the flatness of the flange after overall welding is ±2mm.

[0025] The beneficial effects of this invention are that using this invention to manufacture large flanges not only improves manufacturing precision but also increases manufacturing efficiency. Attached Figure Description

[0026] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort:

[0027] Figure 1 This is a process flow diagram of the present invention;

[0028] Figure 2 This is a schematic diagram of the assembled flange sections. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper surface," "lower surface," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "forward," "reverse," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] like Figure 1 , 2 As shown, a method for manufacturing a large flange includes the following steps:

[0032] Step S1, Flange section preparation: Draw flange drawings and divide the flange into multiple sections. According to the flange drawings, manufacture flange section 1. The flange is divided into 8 sections with 8 butt joints. The bevel angle of each butt joint is 55°. The flange material is ASTM A694.

[0033] Step S2: Draw a pattern line on the flange production site: Draw a pattern cross on the ground of the flange production site, mark the center of the flange at the intersection of the pattern cross and set the anchor point; draw the pattern outline of the flange inner diameter and outer diameter according to the center point, and draw the flange butt plate seam line and 16 equal division lines on the pattern outline.

[0034] Step S3: Arrange the flange jigs along the ground pattern outline: Arrange the prepared flange jigs 2 along the ground pattern outline and fix the flange jigs 2 on the ground of the flange production site.

[0035] Step S4: Draw the outer diameter outline of the flange on each flange jig: Use a total station to draw the outer diameter outline on the flange jig 2 and set the flange punching point.

[0036] Step S5: Assemble the flange on the flange jig: Use an overhead crane to hoist the flange section onto the flange jig 2. One flange section 1 corresponds to three flange jigs 2. The three flange jigs 2 support the middle and both ends of the flange section respectively. Assemble the flange section according to the outer diameter outline, ground cross line, and flange butt plate seam line on the flange jig. After all flange sections are assembled, a circle is formed.

[0037] Step S6, Sealing the Flange Section: Insert the U-shaped clip 3 with the snap-on facing down onto the flange section and position it at the flange jig, so that the U-shaped clip wraps around the flange section. Then weld the U-shaped clip 3 to the flange jig 2, so that the flange section is inserted into the U-shaped clip, leaving a gap between the U-shaped clip and the flange section; the length of the U-shaped clip is not less than 960mm, the height is not less than 450mm, and the thickness is not less than 30mm.

[0038] Step S7: Install the cross brace and fix the flange section: The cross brace includes a central support pier 4, multiple radially arranged horizontal support beams 5 and a connecting plate 6. Install the central support pier 4 at the intersection of the ground cross lines. Connect one end of the horizontal support beam 5 to the central support pier 4. Weld the other end of the horizontal support beam 5 to the U-shaped clip 3 through the connecting plate 6. Insert a wedge-shaped metal block into the gap between the U-shaped clip and the flange section to fix the flange section.

[0039] Step S8: Preheat the flange section weld points: Use electric heating elements to preheat the weld point area of ​​the flange section. The preheating is done using electric heating elements and equipped with thermocouples.

[0040] Step S9, Flange Section Welding: After preheating to the set temperature, begin welding the weld area of ​​the flange section. The specific welding method is as follows: S9.1, complete 1 / 3 of the bevel welding at the upper end of the flange section, then carbide the lower part of the flange section to remove white residue, and complete 1 / 3 of the bevel welding; after cooling, measure the flatness and roundness of the flange section; S9.2, based on the horizontal deviation value of the flatness in the first measurement data, determine the order of the upper and lower bevels during the second welding, and after completing 1 / 3 of the upper and lower bevel welding, cool... S9.3. Measure the flatness and roundness of the flange section; S9.4. Based on the horizontal deviation value of flatness in the second measurement data, determine the order of the upper and lower bevels during the third welding, and complete the welding of the remaining 1 / 3 of the upper and lower bevels. After the welding of this bevel is completed and cooled, measure the flatness and roundness of the flange section; S9.5. Based on the horizontal deviation value of flatness in the measurement data after the completion of the previous bevel welding, determine the order of the upper and lower bevels during the next bevel welding, until all upper and lower bevels are welded; S9.6. After all flange welding is completed, remove the U-shaped clamps and measure the flatness, roundness, and radius of the flange after overall welding.

[0041] After all flange welding is completed, the flange outer diameter is 20160mm, the inner diameter is 19100mm, the flange width is 530mm, the flange thickness is 230mm, and the overall flatness of the flange after welding is ±2mm.

[0042] During the measurement process, changes in flatness are measured by pulling a steel wire, changes in curvature are measured by using an arc template, and changes in radius are measured by using a measuring tape.

[0043] In addition, the welding method used is WPS-950 O2 welding. When the welding is discontinuous, the weld needs to be slowly cooled and kept warm after welding. During the welding process, a dedicated person must monitor the heating temperature and the holding temperature.

[0044] Working principle: This invention effectively fixes each flange section through the cooperation of the flange jig and the star-shaped brace, greatly improving manufacturing accuracy and efficiency. This invention adopts an original welding method, which allows for inspection during the welding process and adjusts the flatness and curvature of the flange by controlling the welding sequence of the upper and lower parts. This welding method results in a high yield and low rework rate, further improving work efficiency.

[0045] Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those embodiments or examples, without contradiction. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for manufacturing a large flange, characterized in that, Includes the following steps: Step S1, Flange section preparation: Draw flange drawings, divide the flange into multiple sections, and manufacture flange sections according to the requirements of the flange drawings; Step S2: Draw the pattern line on the flange production site: Draw the pattern cross on the ground of the flange production site, mark the center of the flange at the intersection of the pattern cross and set the anchor point; draw the pattern outline of the flange inner diameter and outer diameter according to the center point, and draw the flange butt plate seam line and 16 equal division lines on the pattern outline. Step S3: Arrange the flange jigs along the outline of the ground sample: Arrange the multiple flange jigs along the outline of the ground sample and fix the flange jigs on the ground of the flange production site. Step S4: Draw the outer diameter outline of the flange on each flange jig: Use a total station to draw the outer diameter outline on the flange jig and set the flange punch points. Step S5: Assemble the flange on the flange jig: Use an overhead crane to hoist the flange section onto the flange jig. One flange section corresponds to three flange jigs. The three flange jigs support the middle and both ends of the flange section respectively. Assemble the flange section according to the outer diameter outline, ground cross line, and flange butt plate seam line on the flange jig. After all flange sections are assembled, a circle is formed. Step S6, Sealing the flange section: Insert the U-shaped clip with the jaws facing down onto the flange section and position it at the flange jig, and weld the U-shaped clip to the flange jig so that the flange section is inserted into the U-shaped clip, leaving a gap between the U-shaped clip and the flange section. Step S7: Install the cross brace and fix the flange section: The cross brace includes a central support pier, multiple radially arranged horizontal support beams and connecting plates. Install the central support pier at the intersection of the ground cross lines. Connect one end of the horizontal support beam to the central support pier. Weld the other end of the horizontal support beam to the U-shaped clip through the connecting plate. Insert a wedge-shaped metal block into the gap between the U-shaped clip and the flange section to fix the flange section. Step S8: Preheat the flange section weld points: Use electric heating elements to preheat the weld point area of ​​the flange section; Step S9, Flange Section Welding: After preheating to the set temperature, begin welding the weld area of ​​the flange section. The specific welding method is as follows: S9.1, complete 1 / 3 of the bevel welding at the upper end of the flange section, then carbide the lower part of the flange section to remove white residue, and complete 1 / 3 of the bevel welding; after cooling, measure the flatness and roundness of the flange section; S9.2, based on the horizontal deviation value of the flatness in the first measurement data, determine the order of the upper and lower bevels during the second welding, and after completing 1 / 3 of the upper and lower bevel welding, cool... S9.

3. Measure the flatness and roundness of the flange section; S9.

4. Based on the horizontal deviation value of flatness in the second measurement data, determine the order of the upper and lower bevels during the third welding, and complete the welding of the remaining 1 / 3 of the upper and lower bevels. After the welding of this bevel is completed and cooled, measure the flatness and roundness of the flange section; S9.

5. Based on the horizontal deviation value of flatness in the measurement data after the completion of the previous bevel welding, determine the order of the upper and lower bevels during the next bevel welding, until all upper and lower bevels are welded; S9.

6. After all flange welding is completed, remove the U-shaped clamps and measure the flatness, roundness, and radius of the flange after overall welding.

2. The method for manufacturing a large flange according to claim 1, characterized in that: In step S9, after all flange welding is completed, the outer diameter of the flange is 20160mm, the inner diameter is 19100mm, the width of the flange is 530mm, and the thickness of the flange is 230mm.

3. The method for manufacturing a large flange according to claim 2, characterized in that: The flange is made of ASTM A694 material.

4. The method for manufacturing a large flange according to claim 1, characterized in that: In step S1, the flange is divided into 8 sections with 8 butt joints, and the bevel angle of each butt joint is 55°.

5. The method for manufacturing a large flange according to claim 4, characterized in that: In step S6, the length of the U-shaped card code is not less than 960mm, the height is not less than 450mm, and the thickness is not less than 30mm.

6. The method for manufacturing a large flange according to claim 1, characterized in that, In step S9, the change in flatness is measured by pulling a steel wire, the change in curvature is measured by using an arc template, and the change in radius is measured by using a measuring tape.

7. The method for manufacturing a large flange according to claim 1, characterized in that, In step S9, when the welding is discontinuous, the weld needs to be slowly cooled and kept warm after welding. During the welding process, a dedicated person should monitor the heating temperature and the holding temperature.

8. The method for manufacturing a large flange according to claim 1, characterized in that: In step S8, preheating is performed using an electric heating element and equipped with a thermocouple.

9. The method for manufacturing a large flange according to claim 1, characterized in that: In step S9, the welding method used is WPS-950 Oxygen Dioxide Welding.

10. The method for manufacturing a large flange according to claim 1, characterized in that: In step S9, the flatness of the flange after overall welding is ±2mm.

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