Proposal on Carbon Steel Pipe Welding碳钢管道焊接工艺1Technical description 技术特征1.1Pipe material and size: 20# seamless steel pipe材质、规格：20#无缝钢管1.2Work medium：water工作介质：水1.3Designed pressure：4㎏/㎝2设计压力：4㎏/㎝21.4Work pressure：4㎏/㎝2工作压力：4㎏/㎝21.5Test pressure：6㎏/㎝2试验压力：6㎏/㎝22Related documents to this proposal：本工艺编制依据：2.1Technical specification of F06BF06B技术文件2.2GB50236-98《Field Equipment and Industrial Pipe Welding Work Execution and Acceptance Code》国标GB50236-98《现场设备、工业管道焊接工程施工及验收规范》2.3GB50235-97《Industrial Metal Pipe Works Construction andAcceptance Code》国标GB50235-97《工业金属管道工程施工及验收规范》2.4CEFOC Welding Technical Appraisal Report : HG3，HG2002-1 本公司焊接工艺评定报告：HG3，HG2002-1 3Welder焊工3.1Welder should be certified in passing the Welding Examination of Boiler Pressure Container and Pressure Pipe。
焊工应具有“锅炉压力容器压力管道焊工考试规则”规定的焊工考试合格证。
3.2 Welder should pass the qualification test by GB50236-98 Code to obtain work permit of the Contractor before starting the welding work of this project.焊工进入现场后，应按GB50236-98规定，先进行焊接实际操作考试合格。
经总包方认可发证后，方能承担本项目的焊接工作。
3.3 This technical proposal should be complied to during the welding work of this project焊工承担本项目的焊接工作中，应切实执行本焊接工艺。
4 Welding work inspection 焊接检验4.1 Welding inspector should be fully acquainted with the F06B technical specification and both the international standards and this proposal焊接检验人员应F06B技术文件及相关国标和本工艺。
4.2 Inspect the pipe materials and welding materials in accordance with the relevant rules and sign the acceptance form。
对管材焊材按规定进行检验、填表验收。
4.3 Supervise the work of welder and help him to correct any defects in work. To ensure the welding work quality, the inspector is powered to stop the work of any serious offender or those who refuse to correct defects in work。
对焊工是否执行本工艺进行全面监督检查,对违反者进行教育帮助得以改正。
对严重违反者或教育不改者有权令其停止焊接工作。
以确保焊接质量。
4.4 Perform the inspection of welded work in line with Article 7 of this proposal做好本工艺第7条“焊接后检查和管理工作”。
4.5 Coordinate with the representatives of Contractor and Supervisor to participate the inspection邀请和欢迎总包或监理方检验人员进行检查。
5 Preparation work before welding：焊前准备：5 .1 The pipe materials and welding materials are checked to bequalified products管材焊材必须具有符合规定的合格证明，并与实物核对无误。
5.2 Pipe material and size: 20# seamless steel pipe管材型号为20#无缝钢管，规格为DN50至DN2505.3 Welding materials 焊材5.3.1 Argon welding wire model and size: CO2 wire, ∮2.5mm ∮2.0mm氩弧焊焊丝型号规格：CO2保护焊焊丝，∮2.5mm ∮2.0mm 5.3.2 Welding rod model and size: J422 ∮3.2mm ∮2.5mm电焊条规格型号规格：J422 ∮3.2mm ∮2.5mm5.3.3 Ce tungsten pole model and size: WCe-20∮2.0mm铈钨极型号规格：WCe-20∮2.0mm5.3.4 Argon purity: 99.99％。
氩气纯度为99.99％。
5.4 Welding parts preparation 焊件准备5.4.1 The positioning of welding point should comply to GB50235-97 and GB50236-98。
焊接口的分布位置必须符合国标GB50235-97和GB50236-98规范的规定。
5.4.2 The positioning of welding point should comply to GB50235-97 and GB50236-98。
管道为V型坡口，对接接头、组对应符合图1要求：大于此数据，以补收缩。
图1.焊口组对数据5.4.3 The groove of welding parts should be processed by grinding machine and cleaned within 10mm of both inside and outside surface from any oil, dust and burr焊件坡口应用机械或磨光机加工。
焊口组对前应将坡口及其内外表面10mm范围内的油、垢、毛刺等清理干净。
5.4.4 Penetration welding must be applied in spot weld and 4 spots with 5mm of each should be welded on pipe with diameter ≤150mm and 6 spots with 5mm of each should be welded on pipe with diameter ＞150mm.点固焊，根部必须焊透。
不得有焊接缺陷。
管径≤150mm为4点，每点长度为5mm。
管径＞150mm为6点，每点长度为5mm。
5.4.5 The connection of pipe should keep straight in axel and if necessary, make measurement as the flowing chart from 200mmto the center of welding point. The differential allowance is 1mm to pipe with diameter ＜100mm and 2mm to pipe with diameter ≥100mm. The differential allowance to the full length of pipe should be within 10mm and if exceeding that rate, cold correctionthickness of pipe wall. The non penetrated welding as A of the following chart is not allowed.管道组对应内壁齐平，万不得以时，错边量不宜超过壁厚10％，且大于2mm。
焊接时不准有图3a之未焊透。
6.1 The welding equipment must be functioning well.焊接设备性能完好.例如:交流弧焊机应有适当的空载电压;焊接电流调节灵活。
氩弧焊机必须具备非接触引弧、提前送气、迟后关气和焊接电流衰减下破功能。
6.2 Welding method and parameter：焊接方法及焊接工艺参数：6.2.1 When pipe diameter ≤50, use gas welding(oxygen-acetylene welding)with the parameter as the following table:管径≤50mm采用气焊（氧气乙炔焊接），焊接工艺如下：When pipe wall thickness>3mm,groove must to be made, and the groove angle is 650 ，there must not be layer of oxide on the surface of groove.当管材壁厚>3mm时，需倒焊接坡口，坡口角度为650，坡口表面不得有氧化层；When pipe wall thickness≤3mm, the space between the two parts should be 2.5-3mm.✧当管材壁厚≤3mm时焊接管材对口出留出２.５至３mm的焊接缝隙。