A method of pipe reference line surveying

Abstract

A pipe reference line surveying method, before marking, the pipe needs to be ensured without ovality deviation, the long bubble is completely centered, then the magnets on the 135 degree and 225 degree positions of the measuring ring are adjusted, the magnets are close to the pipe wall, the magnets on the 135 degree and 225 degree positions of the ring plate are adsorbed to the pipe wall, forming fixed points, using a stone pen, the reference line points A, B, C, D corresponding to the 0 degree, 90 degree, 180 degree, 270 degree positions are drawn on the outer surface of the steel pipe to be measured in turn, using the same method, the reference line points A'B'C'D' corresponding to the 0 degree, 90 degree, 180 degree, 270 degree positions are drawn on the other end of the steel pipe to be measured, then using a powder line, the reference line points A-A', B-B', C-C', D-D' are used as reference points to draw a line, the through length reference lines AA', B-B', C-C', D-D' are drawn on the pipe wall, and the printing is made, and provided to the segmented part assembly personnel for positioning construction. The application improves the marking precision, improves the marking efficiency, reduces the number of marking personnel, ensures the segmented construction precision, and reduces the shipbuilding cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of offshore ship design and construction, and particularly relates to a method for drawing a reference line of a riser with a diameter of more than 1000 mm installed on an offshore ship. BACKGROUND

[0002] A large-diameter riser structure is installed on the ship side plate of a certain offshore product, and during the process of segmented construction, the riser needs to be nested into the segmented structure and welded with the ship body structure to form an integral segment. The riser has an outer diameter of more than 1 meter, a length of about 3-5 meters, and a wall thickness of about 50 mm. The riser needs to be drawn with 0°, 90°, 180°, and 270° longitudinal reference lines (elementary lines) on the outer wall of the circular pipe before being assembled with the segmented structure. During the segmented assembly, the circular pipe needs to be welded with the structure at the corresponding positions on the outer wall. However, the 0°, 90°, 180°, and 270° reference lines are not drawn on the pipe during the incoming stage, and a kind of auxiliary marking device needs to be designed and manufactured to cooperate with the marking and provide the segmented part for use during the segmented assembly. SUMMARY

[0003] To solve the above problems, the present application provides a method for surveying a reference line of a pipe, and the technical scheme adopted is as follows:

[0004] A method for surveying a reference line of a pipe, the steel pipe to be measured is placed horizontally and fixed by a support leg, a measuring ring is sleeved on the end of the steel pipe to be measured, and 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° scale lines are arranged on the surface of the measuring ring in a circumferential direction at equal intervals. Limiting plates are arranged at the positions of the 0°, 90°, 180°, and 270° scale lines, and the positions of 0°, 90°, 180°, and 270° are detected respectively. The distance between the roller and the pipe wall is adjusted according to the detection value, so that the center of the measuring ring coincides with the center of the circular pipe. A long bubble is arranged at the 0° angle scale line, and the reference surface of the bubble is accurately set to be completely perpendicular to the 0° angle scale line. The reference surface of the limiting plate coincides with the 0°, 90°, 180°, and 270° position lines.

[0005] The stone pen is attached to the limiting plate benchmark surface close to the pipe wall to draw the line, and the gap value between the pipe wall and the ring plate needs to be detected by a ruler or a plug gauge before drawing the line. If the pipe has an ovality deviation, a gasket needs to be attached under the roller until the distance between the ring plate and the pipe wall tends to be the same, that is, the center of the ring plate is coincident with the center of the pipe. Then, whether the long bubble is centered is observed carefully. If the long bubble is not centered, the angle of the ring plate needs to be adjusted so that the long bubble is completely centered. Then, the magnets at the positions of 135 degrees and 225 degrees of the ring plate are adjusted. The magnets are attached to the pipe wall, and the magnets at the positions of 135 degrees and 225 degrees of the ring plate are attracted to the pipe wall to form fixed points. The reference line points A, B, C and D corresponding to the positions of 0 degrees, 90 degrees, 180 degrees and 270 degrees are drawn on the outer surface of the steel pipe to be measured in sequence by using the stone pen. The reference line points A', B', C' and D' corresponding to the positions of 0 degrees, 90 degrees, 180 degrees and 270 degrees are drawn on the other end of the steel pipe to be measured by using the same method. The reference line points A-A', B-B', C-C' and D-D' are used as the reference points to draw the 0-degree, 90-degree, 180-degree and 270-degree reference lines AA', B-B', C-C' and D-D' on the pipe wall by using the chalk line. The printing is made to provide the positioning construction personnel of the segmented part with the positioning construction.

[0006] The pipe reference line surveying method further comprises that the roller is arranged at 45 degrees and 315 degrees, the roller is in contact with the outer surface of the steel pipe to be measured, the magnet is arranged at 135 degrees and 225 degrees, the magnet is in contact with the outer surface of the steel pipe to be measured, the magnet is fixed at the end of the carbon sleeve, the carbon sleeve is supported by the eye plate, the eye plate is vertically fixed on the surface of the measuring ring, the carbon sleeve passes through the eye plate and is fixed by the bolt.

[0007] The pipe reference line surveying method further comprises that the two legs are respectively fixed below the two ends of the pipe.

[0008] The pipe reference line surveying method further comprises that the two eye plates are bonded to the outer surface of the measuring ring by using the glue.

[0009] The pipe reference line surveying method further comprises that the bolt passes through the top of the eye plate and is pressed on the carbon sleeve to fix the carbon sleeve.

[0010] The pipe reference line surveying method further comprises that the surface of the measuring ring is provided with a rectangular groove, the bottom of the eye plate is inserted into the groove and is bonded by using the glue.

[0011] The pipe reference line surveying method improves the line drawing precision and efficiency, reduces the number of workers for line drawing, ensures the segmented construction precision and reduces the shipbuilding cost.

[0012] The pipe reference line surveying method improves the line drawing precision and efficiency, reduces the number of workers for line drawing, ensures the segmented construction precision and reduces the shipbuilding cost. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a front view structural schematic diagram of a measuring ring;

[0014] Figure 2 is a use schematic diagram of measuring a steel pipe to be measured by using the measuring ring;

[0015] Wherein, 1-measuring ring, 2-long bubble, 3-roller, 5-limiting plate, 6-eye plate, 7-carbon tube, 8-hand screw, 9-magnet, 10-steel pipe to be measured, 11-leg, 13-reference line AA'. DETAILED DESCRIPTION

[0016] The application is further described in conjunction with the drawings.

[0017] A pipe reference line surveying method, the steel pipe to be measured is placed in a flat state, a measuring ring with scale lines is designed to be used, the measuring ring is sleeved on the steel pipe to be measured, the measuring ring is provided with a roller, a bubble and a magnet, the 0°, 90°, 180° and 270° reference lines are accurately drawn on the measuring ring plate processed by a carving machine, the 0°, 90°, 180° and 270° reference line points are drawn on the pipe wall by using a stone pen with the help of the accurate reference lines, the reference line points A corresponding to the 0°, 90°, 180° and 270° positions are drawn on the outer surface of the steel pipe to be measured by using a stone pen, the reference line points A, B, C and D corresponding to the 0°, 90°, 180° and 270° positions are drawn on the outer surface of the steel pipe to be measured by using a stone pen in sequence, the same method is used to draw the reference line points A'B'C'D' corresponding to the 0°, 90°, 180° and 270° positions on the other end of the steel pipe to be measured, the powder line is used to draw the 0°, 90°, 180° and 270° reference lines AA', B-B', C-C' and D-D' on the pipe wall with the reference line points A-A'B-B', C-C' and D-D' as the reference points, the printing is made, and the segmented assembly personnel are provided for positioning construction.

[0018] As shown in Figure 1 , the measuring ring is provided with a ring-shaped main plate, the 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° central angle reference lines are accurately drawn on the ring-shaped main plate by using a carving machine or a numerical control machine tool. The rollers are fixed at the 45° and 315° reference lines, the radius of the roller needs to meet the requirement of supporting the ring plate after the roller is installed, so that the ring plate has a uniform gap with the pipe wall.

[0019] The roller is provided with a roller shaft, the roller shaft penetrates through the ring-shaped main plate, the roller is provided with external threads, and the roller shaft with threads is screwed onto the ring-shaped main plate in cooperation with a nut, the roller is tangent to the outer wall of the steel pipe to be measured, and can roll on the steel pipe to be measured.

[0020] The magnets are fixed at 135° and 225° and are in contact with the outer surface of the steel pipe to be measured, and a rectangular hole is formed on the annular main plate, which is completely perpendicular to the 135° and 225° scale lines. The eye plate is embedded in the rectangular hole and is fixed by using glue. The eye plate has two carbon sleeves, which pass through the eye plate and are fixed by bolts. The bolts pass through the top of the eye plate and are on the carbon sleeve to fix the carbon sleeve and prevent the carbon sleeve from moving in the eye plate. The magnets are located at the end of the carbon sleeve.

[0021] A long bubble is arranged near the 0° position of the measuring annular ring, which is completely perpendicular to the 0° reference line. The bubble is completely centered by rolling the roller.

[0022] Limit plates are arranged at the positions of the 0°, 90°, 180° and 270° scale lines, and the surfaces of the limit plates are completely parallel and coincide with the scale lines.

[0023] The 0°, 90°, 180° and 270° positions are detected respectively, and the distance between the roller and the pipe wall is adjusted according to the detection value to make the center of the measuring annular ring coincide with the center of the circular pipe. The magnets at the positions of 135° and 225° of the annular plate are adjusted, the hand screws are loosened, the magnets are tightly attached to the pipe wall, and the fixed points are formed at the positions of 135° and 225° of the annular plate. The reference line points A, B, C and D corresponding to the 0°, 90°, 180° and 270° positions are drawn on the outer surface of the steel pipe to be measured by using a stone pen, and the reference line points A', B', C' and D' corresponding to the 0°, 90°, 180° and 270° positions are drawn on the other end of the steel pipe to be measured by using the same method. The reference line points A-A', B-B', C-C' and D-D' are used as reference points to draw the 0°, 90°, 180° and 270° reference lines AA', B-B', C-C' and D-D' on the pipe wall by using a chalk line, and the lines are printed to provide the segment assembly personnel with positioning construction.

[0024] The present application innovatively and accurately realizes the drawing of the 0°, 90°, 180° and 270° reference lines on the circular pipe structure, improves the line drawing accuracy and efficiency, reduces the number of line drawing personnel, ensures the segment construction accuracy, and reduces the shipbuilding cost.

Claims

1. A method for delineating pipe baselines, characterized in that, The steel pipe to be tested is placed horizontally and fixed by support legs. A measuring ring is fitted onto the end of the steel pipe. Along the circumference of the measuring ring, graduation lines of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° are set at equal intervals. Limiting plates are set at the 0°, 90°, 180°, and 270° graduation lines. A long bubble is set at the 0° graduation line, and the reference plane of the bubble is precisely set to be completely perpendicular to the 0° graduation line. The reference plane of the limiting plate coincides with the 0°, 90°, 180°, and 270° position lines. When marking lines, place the sharpened stone pencil firmly against the reference surface of the limiting plate and extend the marking line to the pipe wall. Before marking, use a ruler or feeler gauge to check the gap between the pipe wall and the ring plate. If the pipe has an elliptic deviation, place shims under the roller until the distance between the ring plate and the pipe wall is closer to the same, i.e., the center of the ring plate coincides with the center of the pipe. Then carefully observe whether the long bubble is centered. If the bubble is not centered, adjust the angle of the ring plate to make the long bubble completely centered. Then adjust the magnets at the 135-degree and 225-degree positions of the ring plate, with the magnets firmly against the pipe wall. Magnets at the designated positions are attached to the pipe wall to form fixed points. Using a chalk, baseline points A, B, C, and D are drawn sequentially on the outer surface of the steel pipe to be tested, corresponding to the 0°, 90°, 180°, and 270° positions. Using the same method, baseline points A'B'C'D' corresponding to the 0°, 90°, 180°, and 270° positions are drawn on the other end of the steel pipe. Then, using chalk lines, baseline points A-A'B-B', C-C', and D-D' are used as reference points to draw continuous baseline lines AA', B-B', C-C', and D-D' on the pipe wall, creating a stamped mark. These marks are then provided to the assembly personnel in the section section for positioning and construction. Rollers are installed at 45° and 315°, where the rollers contact the outer surface of the steel pipe to be tested. Magnets are installed at 135° and 225°, where the magnets contact 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. The eye plate is vertically fixed to the surface of the measuring ring, and the carbon sleeve passes through the eye plate and is fixed by bolts.

2. The pipe baseline delineation method according to claim 1, characterized in that, The support legs are fixed at the bottom of both ends of the round tube.

3. The pipe baseline delineation method according to claim 1, characterized in that, There are two eye plates, which are glued to the outer surface of the measuring ring.

4. The pipe baseline delineation method according to claim 1, characterized in that, The bolt passes through the top of the eye plate and rests against the magnetic post to fix the magnetic post in place.

5. The pipe baseline delineation method according to claim 1, characterized in that, The measuring ring has a rectangular groove on its surface, and the bottom of the eye plate is inserted into the groove and glued together.

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