Pipe datum line assignment method

Abstract

A pipe datum line assignment method includes the steps that it needs to be guaranteed that a pipe is free of ovality deviation and a long bubble is completely centered before lineation, then magnets at 135-degree and 225-degree positions of a measuring ring are adjusted, the magnets are tightly attached to the pipe wall, the magnets at the 135-degree and 225-degree positions of a ring plate are attracted to the pipe wall to form fixing points, and then the pipe datum line is measured. The method comprises the following steps: sequentially drawing datum line points A, B, C and D corresponding to the positions of 0 degree, 90 degrees, 180 degrees and 270 degrees on the outer surface of a steel pipe to be measured by using a slate pencil; and drawing datum line points A 'B' C 'D' corresponding to the positions of 0 degree, 90 degrees, 180 degrees and 270 degrees at the other end of the to-be-measured steel pipe, snapping a line by using a powder line and taking the datum line points A-A 'B-B', C-C 'and D-D' as datum points, drawing full-length datum lines AA ', B-B', C-C 'and D-D' on the pipe wall, performing punching and printing, and providing the full-length datum lines for segmented part assembly personnel for positioning construction. According to the invention, the marking precision is improved, the marking efficiency is improved, the number of marking workers is reduced, the subsection construction precision is ensured, and the shipbuilding cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of offshore ship design and construction, and in particular relates to a method for marking a reference line of a riser with a diameter of more than 1000 mm installed on an offshore ship. Background Art

[0002] A large-diameter riser structure is installed on the side outer plate of a certain marine engineering product. During the segmented construction process, the riser needs to be nested in the segmented structure and welded to the hull structure to form an integral segment. The outer diameter of the riser is more than 1 meter, the length is about 3-5 meters, and the thickness of the tube wall is about 50mm. When the riser is assembled with the segment, it is necessary to first draw the following longitudinal reference lines (plain lines) on the outer wall of the circular tube: 0°, 90°, 180°, and 270°. When assembling the segments, it is necessary to assemble and weld with the structure at the corresponding positions on the outer wall of the circular tube. However, at present, the pipes do not have the following reference lines drawn at the incoming material stage. It is necessary to design and manufacture an auxiliary marking device to cooperate with the marking, which is provided to the segmented part for use during the segmented assembly. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a pipe baseline survey method, the technical solution adopted by the present invention is: A pipe reference line surveying method is provided. A steel pipe to be measured is placed horizontally and fixed by supporting legs. A measuring ring is sleeved on the end of the steel pipe to be measured. 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° scale lines are arranged at equal intervals along the circumference of the measuring ring surface. A limit plate is arranged at the 0°, 90°, 180° and 270° scale lines. The 0°, 90°, 180° and 270° positions are detected respectively. By detecting the values, the distance from the roller to the pipe wall is adjusted so that the center of the measuring ring coincides with the center of the pipe. A long water bubble is arranged at the 0° angle scale line, and the reference surface of the water bubble is accurately set to be completely perpendicular to the 0° angle scale line. The reference surface of the limit plate coincides with the 0°, 90°, 180° and 270° position lines.

[0004] When marking, place the sharpened stone pencil close to the reference surface of the limit plate and extend the marking to the tube wall. Before marking, use a ruler or feeler gauge to check the gap between the tube wall and the ring plate. If the tube has an ovality deviation, place a gasket under the roller until the distance between the circular ring plate and the tube wall becomes more consistent, that is, the center of the circular ring plate coincides with the center of the circular tube; then carefully observe whether the long water bubble is centered. If the water bubble is not centered, adjust the angle of the circular ring plate to make the long water bubble completely centered, and then adjust the magnets at the 135-degree and 225-degree positions of the measuring ring. The magnets are close to the tube wall and the ring plate is centered at 135-degree and 225-degree positions. The magnet at the position is adsorbed on the pipe wall to form a fixed point. The datum line points A, B, C, and D corresponding to the positions of 0°, 90°, 180°, and 270° are drawn on the outer surface of the steel pipe to be tested with a slate pencil. The datum line points A'B'C'D' corresponding to the positions of 0°, 90°, 180°, and 270° are drawn on the other end of the steel pipe to be tested in the same way. Then, with the chalk line, the datum line points A-A'B-B', C-C', and D-D' are used as the datum points to draw the full-length 0°, 90°, 180°, and 270° datum lines AA', B-B', C-C', and D-D' are drawn on the pipe wall, and stamped out to provide to the assembly personnel of the segmented department for positioning construction.

[0005] The above-mentioned pipe baseline surveying method further comprises rollers arranged at 45° and 315°, where the rollers are in contact with the outer surface of the steel pipe to be measured, and magnets arranged at 135° and 225°, where the magnets are in contact with the outer surface of the steel pipe to be measured. The magnets are fixed to the end of the carbon casing, the carbon casing is supported by an eye plate, the eye plate is vertically fixed to the surface of the measuring ring, the carbon casing passes through the eye plate and is fixed by bolts.

[0006] In the above-mentioned pipe reference line surveying method, further, the supporting legs are respectively fixed below the two ends of the circular pipe.

[0007] The above-mentioned pipe reference line surveying method further comprises two eye plates which are bonded to the outer surface of the measuring ring by glue.

[0008] In the above-mentioned pipe reference line surveying method, further, a bolt passes through the top of the eye plate and presses on the carbon sleeve to fix the carbon sleeve.

[0009] The above-mentioned pipe reference line surveying method further comprises the following steps: a rectangular groove is opened on the surface of the measuring ring, and the bottom of the eye plate is inserted into the groove and bonded by glue.

[0010] The present invention improves marking accuracy, improves marking efficiency, reduces the number of people required for marking, ensures segmented construction accuracy, and reduces shipbuilding costs.

[0011] The present invention improves marking accuracy, improves marking efficiency, reduces the number of people required for marking, ensures segmented construction accuracy, and reduces shipbuilding costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the front view structure of the measuring ring; Figure 2 It is a schematic diagram of using a measuring ring to measure the steel pipe to be tested; Among them, 1-measuring ring, 2-long bubble, 3-roller, 5-limiting plate, 6-eye plate, 7-carbon tube, 8-hand screw, 9-magnet, 10-steel tube to be measured, 11-support leg, 13-reference line AA'. DETAILED DESCRIPTION

[0013] The present invention will be further described in conjunction with the accompanying drawings.

[0014] A pipe reference line surveying method, wherein the steel pipe to be measured is placed in a flat state, a measuring ring with scale lines is designed and used, the measuring ring is sleeved on the round pipe to be measured, a roller, a bubble and a magnet are arranged on the measuring ring, 0°, 90°, 180° and 270° reference lines are accurately drawn on the measuring ring plate processed by an engraving machine, with the help of the accurate reference lines, 0°, 90°, 180° and 270° reference line points are drawn on the pipe wall with a stone pen, and the outer surface of the steel pipe to be measured is marked with 0°, 90°, 180° and 270° positions with a stone pen Use a slate pencil to draw the corresponding reference line points A, B, C, and D corresponding to the positions of 0°, 90°, 180°, and 270° on the outer surface of the steel pipe to be tested. Use the same method to draw the reference line points A'B'C'D' corresponding to the positions of 0°, 90°, 180°, and 270° at the other end of the steel pipe to be tested. Then use chalk line to draw the reference line points A-A'B-B', C-C', and D-D' as reference points, and draw the full-length 0°, 90°, 180°, and 270° reference lines AA', B-B', C-C', and D-D' on the pipe wall. Make a print and provide it to the assembly personnel of the segment department for positioning construction.

[0015] like Figure 1 As shown, the measuring ring has an annular main board, and the center angle reference lines of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° are accurately drawn on the annular main board using an engraving machine or a CNC machine tool. Rollers are fixed at the 45° and 315° reference lines, and the radius of the rollers must be sufficient to ensure that the rollers will support the annular plate after installation, so that there is a uniform gap between the annular plate and the pipe wall.

[0016] The roller has a roller shaft which passes through the annular main board. The roller has an external thread which cooperates with a nut. The threaded end shaft of the roller is screwed onto the annular main board. The roller is tangent to the outer wall of the steel pipe to be tested and can roll on the steel pipe to be tested.

[0017] Magnets are fixed at 135° and 225°. At the junction of the magnet and the outer surface of the steel pipe to be tested, a rectangular hole is opened on the annular main board. The rectangular hole is completely perpendicular to the scale lines of the central angle of 135° and 225°. The eye plate is embedded in the rectangular hole and fixed with glue. There are two eye plates. The carbon sleeve passes through the eye plate and is fixed by bolts. The bolts pass through the top of the eye plate and press on the carbon sleeve to fix the carbon sleeve to prevent the carbon sleeve from moving in the eye plate. The magnet is located at the end of the carbon sleeve.

[0018] A long water bubble is set near the 0° position of the measuring ring. The long water bubble is completely perpendicular to the 0° reference line. The water bubble of the measuring ring plate is completely centered by rolling the roller.

[0019] Limit plates are set at the positions of the 0°, 90°, 180°, and 270° scale lines, and the limit plate surfaces are completely parallel and completely coincide with the scale lines.

[0020] Detect the positions of 0°, 90°, 180°, and 270° respectively, and adjust the distance from the roller to the pipe wall by detecting the values ​​so that the center of the measuring ring coincides with the center of the pipe; adjust the magnets at the 135° and 225° positions of the measuring ring, loosen the hand screws, and the magnets are close to the pipe wall to form fixed points at the 135° and 225° positions of the ring plate. Use a slate pencil to draw the reference line points A, B, C, and D corresponding to the positions of 0°, 90°, 180°, and 270° on the outer surface of the steel pipe to be tested in sequence. Use the same method to draw the reference line points A'B'C'D' corresponding to the positions of 0°, 90°, 180°, and 270° at the other end of the steel pipe to be tested. Then use chalk line to draw the reference line points A-A'B-B', C-C', and D-D' as reference points to draw the full-length 0°, 90°, 180°, and 270° reference lines AA', B-B', C-C', D-D' are printed and provided to the assembly personnel of the section department for positioning and construction.

[0021] The present invention innovatively and highly accurately draws 0°, 90°, 180°, and 270° reference lines on a circular tube structure, thereby improving marking accuracy, improving marking efficiency, reducing the number of people required for marking, ensuring segmented construction accuracy, and reducing shipbuilding costs.

Claims

1. A pipe baseline survey method, characterized in that: The steel pipe to be tested is placed horizontally and fixed by supporting legs. A measuring ring is sleeved on the end of the steel pipe to be tested. 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° scale lines are arranged at equal intervals along the circumference of the measuring ring surface. Limit plates are arranged at the 0°, 90°, 180°, and 270° scale lines; a long water bubble is arranged at the 0° angle scale line, and the reference surface of the water bubble is accurately set to be completely perpendicular to the 0° angle scale line; the reference surface of the limit plate coincides with the 0°, 90°, 180°, and 270° position lines; When marking, place the sharpened stone pencil close to the reference surface of the limit plate and extend the marking to the tube wall. Before marking, use a ruler or feeler gauge to check the gap between the tube wall and the ring plate. If the tube has an ovality deviation, place a gasket under the roller until the distance between the circular ring plate and the tube wall becomes more consistent, that is, the center of the circular ring plate coincides with the center of the circular tube; then carefully observe whether the long water bubble is centered. If the water bubble is not centered, adjust the angle of the circular ring plate to make the long water bubble completely centered, and then adjust the magnets at the 135-degree and 225-degree positions of the measuring ring. The magnets are close to the tube wall and the ring plate is centered at 135-degree and 225-degree positions. The magnet at the position is adsorbed on the pipe wall to form a fixed point. The datum line points A, B, C, and D corresponding to the positions of 0°, 90°, 180°, and 270° are drawn on the outer surface of the steel pipe to be tested with a slate pencil. The datum line points A'B'C'D' corresponding to the positions of 0°, 90°, 180°, and 270° are drawn on the other end of the steel pipe to be tested in the same way. Then, with the chalk line, the datum line points A-A'B-B', C-C', and D-D' are used as the datum points to draw the full-length 0°, 90°, 180°, and 270° datum lines AA', B-B', C-C', and D-D' are drawn on the pipe wall, and stamped out to provide to the assembly personnel of the segmented department for positioning construction.

2. A pipe baseline survey method according to claim 1, characterized in that: Rollers are arranged at 45° and 315°, where the rollers are in contact with the outer surface of the steel pipe to be tested; magnets are arranged at 135° and 225°, where the magnets are in contact with the outer surface of the steel pipe to be tested; the magnets are fixed to the end of the carbon sleeve, which is supported by an eye plate, which is vertically fixed to the surface of the measuring ring, and the carbon sleeve passes through the eye plate and is fixed by bolts.

3. A pipe baseline survey method according to claim 1, characterized in that: The legs are respectively fixed below the two ends of the round tube.

4. A pipe baseline survey method according to claim 2, characterized in that: There are two eye plates, which are bonded to the outer surface of the measuring ring by glue.

5. A pipe baseline survey method according to claim 2, characterized in that: The bolt passes through the top of the eye plate and presses against the magnetic column to fix the magnetic column.

6. A pipe baseline survey method according to claim 2, characterized in that: A rectangular groove is opened on the surface of the measuring ring, and the bottom of the eye plate is inserted into the groove and bonded by glue.

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