阅读说明：本技术 一种煤气管网水封三角法装配施工方法 (Gas pipe network water-seal triangular method assembling construction method ) 是由 王志鹏 沈俊姣 冯永辉 龙春梅 李鹏 席林 于 2019-11-01 设计创作，主要内容包括：本发明公开了一种煤气管网水封三角法装配施工方法,根据设计图纸统计不同型号规格水封、弯头、大小头分类统计,订购材料,材料进场后,在制作场地进行下料、打磨、卷制、焊接、切割组对,在装配平台上做好控制线,做好标记；弯头实际尺寸控制好后,再根据实际尺寸补齐中间直管段,并使用三角法来控制组装精度,先点焊固定然后间断焊接,采用由中间向两侧退焊的方式进行焊接。本发明在保证整体质量的前提下,有效提高了水封的安装速度,大大缩短了工期,同时,节约了吊车使用台班费,提高了工程经济效益。(The invention discloses a gas pipe network water seal triangular method assembling construction method, which includes the steps of carrying out statistics on water seals, elbows and large and small heads of different types and specifications according to a design drawing, carrying out classification statistics on ordered materials, carrying out blanking, polishing, rolling, welding and cutting assembly on a manufacturing site after the materials enter the manufacturing site, and making a control line on an assembling platform and marking the control line; after the actual size of the elbow is well controlled, the middle straight pipe section is filled according to the actual size, the assembly precision is controlled by using a trigonometry method, spot welding is firstly carried out for fixation, then intermittent welding is carried out, and welding is carried out in a mode of backing welding from the middle to two sides. On the premise of ensuring the overall quality, the invention effectively improves the installation speed of the water seal, greatly shortens the construction period, saves the overhead of a crane use platform and improves the economic benefit of engineering.)

1. The gas pipe network water-seal triangular method assembling construction method is characterized by comprising the following steps of:

s1, performing examination chart statistical calculation: according to the design drawing, water seals, elbows and large and small heads of different models and specifications are counted in a classified mode, and materials are ordered;

s2, setting out steel plate snapping line: selecting a blanking platform steel plate according to the weight of pipeline assembly;

s3, cutting and blanking: cutting and blanking by using a numerical control machine tool, and bidirectionally sizing a steel plate according to the size of a coiled pipeline to avoid cross-shaped welding seams;

s4, cleaning and grinding the groove: grinding the groove and removing oxidation slag;

s5, rolling, spot welding:

(1) the plate bending machine is formed by adopting a pressure head-free rolling mode, a circle correcting sample plate of a rolled pipe is 1/4 of the circumference of the pipe, and a gap between the sample plate and the inner wall of the pipe is 1-2 mm;

(2) after the rolling plate is manufactured, checking chord length and diagonal line, making marks for recording the central line in the circumferential direction at 0 ℃, 90 ℃, 180 ℃ and 270 ℃, making a control line, and making an embossed mark;

(3) straight tube welding, wherein an arc striking plate and an arc extinguishing plate are welded firstly, the width of the arc striking plate is not less than 150mm, the length of the arc extinguishing plate is not less than 200mm, when double-wire submerged arc welding is used for striking an arc, two welding wires are not simultaneously struck, the front wire is firstly struck, and after the arc is stabilized and advances by 30-50mm, the rear wire is struck on the surface of a molten pool where the front wire is not solidified; stopping the arc of the front wire, and extinguishing the arc of the rear wire after the arc pits are filled with the rear wire;

(4) the straight pipe is supported and welded, and the support is welded after the rolling is finished;

s6, cutting the pipe tile template: when the template cuts and baits, the longitudinal welding line of the reel pipe is arranged at the upper part, meanwhile, no hole is formed on the welding line of the pipeline and the edge of the welding line, the reel pipe is provided with a reinforcing ring, the butt welding line of the reinforcing ring is staggered with the longitudinal welding line of the pipe, the distance between the butt welding line of the reinforcing ring and the longitudinal welding line of the pipe is not less than 100mm, and the distance between the reinforcing ring and the circumferential welding line of;

s7, assembling, checking and welding:

(1) assembling the pipe tiles on an assembling platform, controlling the levelness of the assembling platform within a standard range, wholly settling within an allowable range under impact force, amplifying the plate width by 2-3mm, and controlling the assembling clearance by using a fixed clamping plate during assembling while considering the shrinkage and the repairing amount;

(2) water seal integral assembly: laying out and drawing a control line according to the actual size of the water seal on an assembly line, marking, after controlling the three elbows according to the actual size, filling the middle straight pipe section according to the actual size, strictly controlling the size length and checking the angle, wherein the steel plate is a double-fixed-length steel plate, only one longitudinal welding line is arranged, the position of the welding line is staggered by 90 degrees from the central line of the large tile and the small tile, and the welding line is positioned in the middle of the pipeline;

(3) checking the size of the U-shaped bend: solving the actual distance AB between the center lines of the two ends of the elbow according to the following formula, wherein if AB is greater than the theoretical length, the angle a is increased; if AB is less than the theoretical length, the angle a is reduced, and welding is carried out after complete repair;

AB＝(0A²+OB²-2OAxOBxCOSa)^1/2，

wherein AB is the actual distance between the center lines of the two ends of the elbow;

a is a water seal angle;

OA and OB are the actual lengths of the straight tube sections.

2. The gas pipe network water-seal triangular method assembling construction method according to claim 1, wherein in step S2, the flatness of the blanking platform is controlled to be 1-3mm, and the thickness of the steel plate of the blanking platform is not less than 20 mm.

3. The gas pipe network water seal triangular method assembling construction method according to claim 1, wherein the groove in step S4 is an X-shaped groove, a V-shaped groove or a K-shaped groove, and a truncated edge is required to be left, and the groove size and the truncated edge should meet design requirements.

4. The gas pipe network water-seal triangular assembling construction method according to claim 1, wherein the allowable deviation of the chord length in step S5 is ± 2.0mm, and the allowable deviation of the diagonal line is ± 3.0 mm.

5. The gas pipe network water-seal triangular method assembling construction method according to claim 1, wherein the welding support in step S5 is:

DN is less than or equal to 1200, and the plate thickness delta is less than or equal to 6mm, and the cross brace with the length of L70x 5m is selected for fixation;

DN is more than or equal to 1300 and less than or equal to 2400, the plate thickness is more than or equal to 8 and less than or equal to 10mm, and L90x6 m-shaped supports are selected for fixation;

DN is more than or equal to 2500 and less than or equal to 4600, plate thickness is more than or equal to 10 and less than or equal to 16mm, and L110x8 m-shaped supports are selected for fixation.

6. The gas pipe network water-seal triangular method assembling construction method according to claim 1, wherein the control lines in step S8 are: a water seal height difference control line, a water seal width control line and an elbow central line control line.

7. The gas pipe network water seal triangular method assembling construction method according to claim 1, wherein the water seal assembly in step S8 adopts a construction process of spot welding first, then breaking and then full welding, first, middle and then two ends, first, elbow and then straight section, first, lower and then upper, and the assembly sequence is as follows: the lower elbow, the left upper elbow, the right upper elbow and the straight pipe section are adjusted.

8. The gas pipe network water seal triangular method assembling construction method according to claim 1, wherein the assembling check welding in step S8 further comprises spot welding and fixing, then intermittent welding, the spot welding length is 50-80mm, the height of the welding seam is 3-6mm, the spacing between the welding seams is 400mm, after the spot welding is finished, gas shielded welding is adopted, and the welding is performed from the middle to the two sides according to the welding specification requirements, the inner side is welded for 2 times, then the carbon arc gouging is adopted to remove roots from the outer side, and the outer side seam is welded, and the position of the welding seam between layers is staggered.

9. The gas pipe network water seal triangular method assembling construction method according to claim 8, wherein welding wires ER50-6 and phi 1.2mm are used in the gas shielded welding, and shielding gas is CO₂。

Technical Field

The invention relates to a water seal assembly method, in particular to a gas pipe network water seal triangle method assembly construction method in large-scale steel enterprises gas pipe network facilities and dust removal pipeline technical improvement and maintenance engineering.

Background

The gas pipe network facilities of the iron and steel enterprises generally comprise facilities of full-scale gas storage, secondary purification, mixing, pressurized conveying, oxygen production and hydrogen production by coke oven gas and the like, and mainly provide energy power for blast furnaces, coal injection, lime rotary kilns, steel making, continuous casting, hot rolling, cold rolling, wide and thick plates and the like. The gas pipeline cuts off and can use butterfly valve, blind plate valve or blind plate, and the gas that nominal diameter is greater than 600mm needs to use electronic butterfly valve and electronic blind plate valve, because the gas pipeline pipe diameter in the iron and steel enterprise is often very big, and a lot of has surpassed 2000mm, and electronic butterfly valve and electronic blind plate valve on the major diameter gas pipeline are very high, and the impurity in the gas pipeline is more easily to cause the sediment in addition, traditional gate valve uses can not reach the sealing effect after a period, needs the periodic replacement, has brought heavy burden for the production operation of enterprise.

The gas water seal is a device for preventing gas from flowing by using the static pressure of water, and has four functions: (1) the condensed water discharging pipe is used for discharging condensed water accumulated in the pipe; (2) used for cutting off the gas pipeline; (3) the device is used for gas non-return; (4) the expansion joint acts.

The water seal cutting equipment mainly comprises three types of U-shaped water seals, three-way water seal valves and water seal check valves. The U-shaped water seal generally comprises a U-shaped water seal pipeline, a flow regulating valve, a water inlet system, an overflow system, a bleeding system and an operating platform, is widely applied to a main gas pipeline in a steel enterprise at present, is generally arranged behind a butterfly valve, and can realize reliable gas cut-off after water injection.

The large/medium-sized repair of the gas pipeline causes that the subsequent steel making, continuous casting and steel rolling can not be produced at full load, thereby affecting the production benefit of enterprises, and in order to reduce the influence of the gas pipeline repair on the subsequent production, the requirement of owners on the construction period is severer.

In large gas pipelines and technical improvement projects, a gas water seal pipeline occupies a gas pipeline, and particularly occupies a large amount in a pressurizing station. The water seal is formed by manually welding and assembling a plurality of tiles and elbows, and a reasonable assembling method is particularly important. Meanwhile, the manufacturing quality of the water seal pipeline directly influences the installation progress of the whole follow-up gas pipeline, and the shortening of the construction period is a key factor for ensuring the total construction period.

The traditional water seal adopts a manufacturing method of assembling from one side to the other side, so that accumulated errors are easily caused in tile assembly, and the dimension of a finally assembled lower bent pipe section is not easy to adjust; meanwhile, the problems of wasting mechanical machine shifts, increasing the difficulty of manual assembly, low assembly efficiency, increasing potential safety hazards and the like exist in the field installation and assembly of the dispersed manufacturing.

Disclosure of Invention

In order to overcome the defects of the prior art, the gas pipe network water-seal triangular method assembling construction method is provided, the installation speed is effectively improved on the premise of ensuring the overall quality, the construction period is greatly shortened, the shift cost of a crane using platform can be saved, and the engineering economic benefit is improved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a gas pipe network water seal triangular method assembling construction method comprises the following specific steps:

s1, performing examination chart statistical calculation: counting water seals, elbows and large and small heads of different models and specifications according to design drawings in a classified manner, and ordering materials;

s2, setting out steel plate snapping line: selecting a blanking platform steel plate according to the weight of pipeline assembly; the flatness of the blanking platform is controlled to be 1-3mm, and the thickness of a steel plate of the blanking platform is not less than 20 mm;

s3, cutting and blanking: cutting and blanking by using a numerical control machine tool, and bidirectionally sizing a steel plate according to the size of a coiled pipeline to avoid cross-shaped welding seams;

s4, cleaning and grinding the groove: grinding the groove and removing oxidation slag;

s5, rolling, spot welding:

(1) the plate bending machine is formed by adopting a pressure head-free rolling mode, and a steel bracket is arranged on a rolling pipe and an upper roller of the plate bending machine is used for processing; the circle correcting template of the reel pipe is 1/4 of the circumference of the pipe, and the gap between the template and the inner wall of the pipe is not 1-2 mm;

(2) after the rolling plate is manufactured, chord length and diagonal line are checked, marks of 0 ℃, 90 ℃, 180 ℃ and 270 ℃ of the central line in the circumferential direction are recorded, control lines are manufactured, steel seal marks are manufactured, roundness and circumference deviation are key factors influencing water seal assembly, and the circumference and the roundness deviation of a pipeline are shown in the following table:

(3) straight tube welding, wherein an arc striking plate and an arc extinguishing plate are welded firstly, the width of the arc striking plate is not less than 150mm, the length of the arc extinguishing plate is not less than 200mm, when double-wire submerged arc welding is used for striking an arc, two welding wires are not simultaneously struck, the front wire is firstly struck, and after the arc is stabilized and advances for a certain distance (30-50 mm), the rear wire strikes the surface of a molten pool where the front wire is not solidified; stopping the arc of the front wire, and extinguishing the arc of the rear wire after the arc pits are filled with the rear wire;

(4) straight pipe support welding: welding and supporting after the rolling is finished;

s6, cutting the pipe tile template: when the template cuts and baits, the longitudinal welding line of the reel pipe is arranged at the upper part, meanwhile, no hole is formed on the welding line of the pipeline and the edge of the welding line, the reel pipe is provided with a reinforcing ring, the butt welding line of the reinforcing ring is staggered with the longitudinal welding line of the pipe, the distance between the butt welding line of the reinforcing ring and the longitudinal welding line of the pipe is not less than 100mm, and the distance between the reinforcing ring and the circumferential welding line of;

s8, assembling, checking and welding:

(1) assembling the pipe tiles on an assembling platform, controlling the levelness of the assembling platform within a standard range, wholly settling within an allowable range under impact force, amplifying the plate width by 2-3mm, and controlling the assembling clearance by using a fixed clamping plate during assembling while considering the shrinkage and the repairing amount;

(2) water seal integral assembly: on an assembly line, well laying out and drawing a control line according to the actual size of a water seal, marking, after controlling the three elbows according to the actual size, filling the middle straight pipe according to the actual size, strictly controlling the size length and checking the angle, wherein the steel plate is a double-fixed-length steel plate, only one longitudinal welding line is arranged, the position of the welding line is staggered by 90 degrees from the central line of the large tile and the small tile, and the welding line is positioned in the middle of the pipeline, so that the welding line is effectively prevented from being positioned at the lower part;

(3) checking the size of the U-shaped bend: and solving the actual distance AB between the center lines of the two ends of the elbow according to the following formula:

AB＝(0A²+OB²-2OAxOBxCOSa)^1/2if AB is>The theoretical length, the angle a becomes larger; if AB<The theoretical length is that the angle a is reduced, and welding is carried out after the repairing is complete;

wherein AB is the actual distance between the center lines of the two ends of the elbow;

a is a water seal angle;

OA and OB are the actual lengths of the straight tube sections.

Furthermore, the flatness of the blanking platform in the step S2 is controlled to be 1-3mm, and the thickness of the steel plate of the blanking platform is not less than 20 mm.

Further, in the step S4, the groove is an X-shaped groove, a V-shaped groove or a K-shaped groove, a truncated edge is required to be left, and the groove size and the truncated edge should meet design requirements.

Further, the allowable deviation of the chord length in step S5 is ± 2.0mm, and the allowable deviation of the diagonal line is ± 3.0 mm.

Further, the welding support in step S5 is:

DN is less than or equal to 1200, and the plate thickness delta is less than or equal to 6mm, and the cross brace with the length of L70x 5m is selected for fixation;

DN is more than or equal to 1300 and less than or equal to 2400, the plate thickness is more than or equal to 8 and less than or equal to 10mm, and L90x6 m-shaped supports are selected for fixation;

DN is more than or equal to 2500 and less than or equal to 4600, plate thickness is more than or equal to 10 and less than or equal to 16mm, and L110x8 m-shaped supports are selected for fixation.

Further, the control lines in step S8 are: a water seal height difference control line, a water seal width control line and an elbow central line control line.

Further, the water seal assembly in step S8 is performed by spot welding, then breaking and then full welding, the construction processes of first middle and then two ends, first elbow and then straight section, first lower part and then upper part are paired on the assembly platform, and the assembly sequence is as follows: the lower elbow, the left upper elbow, the right upper elbow and the straight pipe section are adjusted.

Further, the assembly, verification and welding in the step S8 further comprises the steps of firstly fixing by spot welding and then welding discontinuously, wherein the spot welding length is 50-80mm, the height of a welding line is 3-6mm, the interval between the welding lines is 400mm, after the spot welding is finished, gas shielded welding is adopted, the welding is performed from the middle to two sides according to the welding specification, the inner side is welded for 2 times, then carbon arc gouging is adopted to remove roots from the outer side, the outer side seam is welded, and the arc starting and arc receiving positions of the welding lines between layers are required to be staggered.

Further, welding wires ER50-6 and phi 1.2mm for gas shielded welding are adopted, and shielding gas is CO₂。

The invention has the beneficial effects that:

(1) the construction period can be shortened, and more operation time is provided for subsequent operation;

(2) the working machine class is saved, the overhead working time is reduced, and the safety operation guarantee is improved;

(3) the service life of the water seal is prolonged, the investment amount of an owner project is saved, and the construction maintenance times are reduced.

Drawings

FIG. 1 is a water seal triangle method control assembly drawing of the gas pipe network of the present invention;

in the figure, 1, a lower elbow, 2, a left upper elbow, 3, a right upper elbow, 4, a straight pipe section, 5, a water seal elevation difference control line, 6, a water seal width control line, 7, an elbow central line control line, a water seal angle, A, a water seal elevation difference control line and an intersection point of a water seal width control line on one side; B. the intersection point of the height difference control line of the water seal mark and the water seal width control line at the other side, O and the intersection points of the water seal width control lines at the two sides.

Detailed Description

For a better understanding of the present invention, the present invention will be further explained below with reference to the accompanying drawings and examples, which are set forth only to help to understand the method of the present invention and its core concept. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The following description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Accordingly, the invention is not to be limited to the embodiments shown herein.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Fig. 1 is a water seal triangle method control assembly drawing of the gas pipe network of the present invention, the water seal comprises a lower elbow 1, a left upper elbow 2, a right upper elbow 3 and a straight pipe section 4, wherein, during assembly, the lower elbow 1, the left upper elbow 2 or the right upper elbow 3 and the straight pipe section are adjusted in sequence, the left upper elbow 2 or the right upper elbow 3 is kept at the same height through a water seal height difference control line 5 at the center, a water seal width control line 6 is arranged at the center of the straight pipe section 4, an elbow center control line 7 is arranged at the center of the lower elbow 1, the water seal width control lines 6 at both sides are intersected at O point, the included angle is water seal angle a, and the water seal height difference control line 5 and the water seal width control lines 6 at both sides are respectively intersected at the two points a and B.

A water seal assembly construction method for a gas pipe network comprises the following steps:

s1, performing examination chart statistical calculation: counting water seals, elbows and large and small heads of different models and specifications according to design drawings in a classified manner, and ordering materials;

s2, setting out steel plate snapping line: selecting a blanking platform steel plate according to the weight of pipeline assembly; the flatness of the blanking platform is controlled to be 1-3mm, and the thickness of a steel plate of the blanking platform is not less than 20 mm;

s3, cutting and blanking: cutting and blanking by using a numerical control machine tool, and bidirectionally sizing a steel plate according to the size of a coiled pipeline to avoid cross-shaped welding seams;

s4, cleaning and grinding the groove: grinding the groove and removing oxide slag, wherein the groove is an X-shaped groove, a V-shaped groove or a K-shaped groove, a truncated edge is required to be reserved, and the size and the truncated edge of the groove meet the design requirements;

s5, rolling, spot welding:

(1) the plate bending machine is formed by adopting a pressure head-free rolling mode, and a steel bracket is arranged on a rolling pipe and an upper roller of the plate bending machine is used for processing; the circle correcting template of the reel pipe is 1/4 of the circumference of the pipe, and the gap between the template and the inner wall of the pipe is not 1-2 mm;

(2) after the rolling plate is manufactured, chord length and diagonal line are checked, marks of 0 ℃, 90 ℃, 180 ℃ and 270 ℃ of the central line in the circumferential direction are recorded, control lines are manufactured, steel seal marks are manufactured, roundness and circumference deviation are key factors influencing water seal assembly, and the circumference and the roundness deviation of a pipeline are shown in the following table:

the allowable deviation of the chord length is +/-2.0 mm, and the allowable deviation of the diagonal line is +/-3.0 mm;

(3) straight tube welding, wherein an arc striking plate and an arc extinguishing plate are welded firstly, the width of the arc striking plate is not less than 150mm, the length of the arc extinguishing plate is not less than 200mm, when double-wire submerged arc welding is used for striking an arc, two welding wires are not simultaneously struck, the front wire is firstly struck, and after the arc is stabilized and advances for a certain distance (30-50 mm), the rear wire strikes the surface of a molten pool where the front wire is not solidified; stopping the arc of the front wire, and extinguishing the arc of the rear wire after the arc pits are filled with the rear wire;

(4) straight pipe support welding: after the rolling is finished, the support is welded, wherein,

DN is less than or equal to 1200, and the plate thickness delta is less than or equal to 6mm, and the cross brace with the length of L70x 5m is selected for fixation;

DN is more than or equal to 1300 and less than or equal to 2400, the plate thickness is more than or equal to 8 and less than or equal to 10mm, and L90x6 m-shaped supports are selected for fixation;

DN is more than or equal to 2500 and less than or equal to 4600, plate thickness is more than or equal to 10 and less than or equal to 16mm, and L110x8 m-shaped supports are selected for fixation;

s6, cutting the pipe tile template: when the template cuts and baits, the longitudinal welding line of the reel pipe is arranged at the upper part, meanwhile, no hole is formed on the welding line of the pipeline and the edge of the welding line, the reel pipe is provided with a reinforcing ring, the butt welding line of the reinforcing ring is staggered with the longitudinal welding line of the pipe, the distance between the butt welding line of the reinforcing ring and the longitudinal welding line of the pipe is not less than 100mm, and the distance between the reinforcing ring and the circumferential welding line of;

s7, assembling, checking and welding:

(1) assembling the pipe tiles on an assembling platform, controlling the levelness of the assembling platform within a standard range, wholly settling within an allowable range under impact force, amplifying the plate width by 2-3mm, and controlling the assembling clearance by using a fixed clamping plate during assembling, wherein the shrinkage and the repair amount are considered;

(2) water seal integral assembly: well setting out and well marking a control line according to the actual size of the water seal on an assembly line, and marking the control line, wherein the control line comprises the following components in parts by weight: the three functions of the control lines are water seal height difference control, water seal width (length) and elbow central line (or sideline control), after the three elbows of the lower elbow 1, the left upper elbow 2 and the right upper elbow 3 are well controlled according to actual size, the middle straight pipe section 4 is supplemented according to the actual size, the size length is strictly controlled, the angle is checked, the steel plate is a double-fixed-length steel plate, only one longitudinal welding line is arranged, the position of the welding line is staggered by 90 degrees from the central line of the large tile and the small tile, and the welding line is positioned in the middle of the pipeline, so that the welding line is effectively prevented from being positioned at the lower part;

(3) the construction process of spot welding, breaking and full welding, the middle part, the two ends, the elbow and the straight section, the lower part and the upper part are assembled on an assembly platform, and the assembly sequence is that the lower elbow 1, the upper left elbow 2 or the upper right elbow 3 and the straight pipe section 4 are adjusted;

(4) checking the size of the U-shaped bend: specifically, a triangle method is used for calculating, the distance between the middle lines at the two ends of the elbow is calculated according to the known length of the two sides and the included angle, the water seal width control lines at the two sides are intersected at the point O, the included angle is a water seal angle a, a water seal elevation difference control line 5 and water seal width control lines at the two sides 6 are respectively intersected at the point A and the point B, and OA and OB can be set as the actual length of the straight pipe section;

the actual distance AB between the center lines of the two ends of the left upper elbow 2 and the right upper elbow 3 is calculated according to the following formula,

AB＝(0A²+OB²-2OA×OB×COSa)^1/2，

if AB > the theoretical length, the angle a becomes larger; AB is less than the theoretical length, the angle a is reduced, and welding is carried out after complete repair;

(5) fixing by spot welding, and then intermittently welding, wherein the spot welding length is 50-80mm, the height of a welding line is 3-6mm, the interval of the welding line is-400 mm, and after spot welding is finished, CO is adopted₂Gas shielded welding (welding wire ER50-6, phi 1.2mm), backing from the middle to two sides according to the requirement of welding specification, welding the inner side for 2 times, then adopting carbon arc gouging to back off and welding the outer side seam, paying attention to the start and end positions of the interlayer welding seamThe placement should be staggered.

And S8, fixedly welding the water seal bracket and the jacking device and performing anticorrosive coating.

The gas pipe network water seal triangular method assembly construction method improves the manufacturing precision, effectively shortens the construction period, correspondingly saves the labor cost, the platform use cost for installing machines and tools and the construction management cost, for example, one water seal of phi 3600x10 can be assembled for 1 day by 5 working days when the water seal is used; while the traditional method needs 2.5 days and 12.5 working days; the labor cost is 220 yuan/working day, the labor cost is saved by 1650 yuan/working day, the comprehensive pipe network is about 60, and the cost is saved by 99000 yuan; about 150 gas pressurization stations save cost 247500 yuan.

The invention has been successfully applied to No. 2 blast furnace gas pipe network engineering from Xiang steel 5m wide and thick plates in 2008, the construction is smooth, the manufacturing period is greatly shortened, and the manufacturing quality is improved. After that, the coal gas pipe network water seal triangular method assembly construction method is adopted in three-section 1-5# coal gas pressurizing station engineering of Zhanjiang steel whole plant gas engineering in 2014, four-section small hydrogen making station of Zhanjiang steel whole plant gas engineering in 2015 and circulating economic project of Zhanjiang steel and Chinese refining chemical energy supply in 2018 of Bagang steel group, the construction period is effectively shortened, and good effects are obtained.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.