《管台焊接程序课件.ppt》由会员分享，可在线阅读，更多相关《管台焊接程序课件.ppt（28页珍藏版）》请在三一办公上搜索。
1、管台焊接程序,管台焊接程序管台焊接程序ASIA Construction Engineering Training Conference FY 2007ASIA CONSTRUCTION:BUILDING AIR PRODUCTS FUTURESeptember 18 to 22,2006,Welding set up,Ready to weld:Every fitting is shaped to fit the pipe and self-aligning 焊接准备：每一个管台都被加工成适合管道的形状，以便对正The outlet is machine-beveled for quick
2、easy butt-welding of branch pipe for shop or field fabrication管台焊接处被加工成坡口，以适合车间或现场支管快速对焊,Welding set up,Lay out:the template is inside of the fittingCut hole:the hole in the run pipe on reducing sizes can be cut out either before or after the fitting is welded on.The hole can be cut with drill or a
3、hole saw.Welding the fitting to run pip prior to cutting the hole helps prevent distortion of the run pipe and can be done generally on outlet size over two inches 放置模板于管台内部 开孔：变径管台在主观上的开孔既可以在焊接前也可在焊接后再开。可以用钻孔，也可用孔据开孔。先在主管上焊管台后开孔可以防止主管扭曲，一般适用大于2英寸的管台。,Welding set up,Space for welding:The weldolet is
4、 raised off the run pipe to establish proper weld gap by placing spacers,e.g.welding rods under the fitting.This provides a uniform welding gap between the curvature of the run and base of fitting 焊接间隙：管台焊接前要保证与主管的焊接间隙，例如放一根焊条在管台和主管之间。这样可以保证焊接根部间隙均匀。,Welding set up,Tack weld:The base joint is tack w
5、elded,preferably at four points,each half way between the crotch and skirt sections of fitting.The spacers are the removed 点焊：根部需要点焊，建议4点，分布在管台的肩部，同时移掉间隙物。,Welding sequence,Longitudinal section:Wide bases or footings at crotch section distribute internal and external stresses.Gradual changes of sect
6、ion eliminate stress concentration.Funnel shaped opening provides improved flow direction 纵断面：分叉处存在内外应力，截面渐变消除了应力集中。漏斗状开口有利于流体流动。,Welding sequence,Transverse section:Note the blending of the skirt section weldolet to the run pipe to avoid abrupt change in intersection.Throat of weld at this point is
7、 designated by the welding bevel.横断面：管台裙叉处和主管处的坡口过渡可以避免交叉点的急剧变化，,Welding sequence,Stringer bead:The stringer bead is applied completely around the base of the fitting.The established weld gap assures full penetration线型焊道：线型焊道紧紧环绕管台焊接，焊道间隙可以保证完全焊透。,Welding sequence,Reinforcing beads:Reinforcing welds
8、 should be made at the crotch bevel areas of the fitting to provide maximum weld at the crotch tapering to minimum at the skirt.Particular are should be taken to weld only the bevel portion of the fitting.This eliminates the unnecessary use of continuous passes and prevents the erroneous practice of
9、 welding up to the rib on the skirt portion of fitting.A continuous cover bead should be added to fill the bevel and provide a smooth tapered weld.加强焊道：加强焊道应该在管台分叉处坡口进行最大焊接，而在裙尖处进行最小焊接，特别是焊接坡口部分。这就是说可以减少一些连续焊接，防止裙尖处的过渡焊接。连续的焊接应填满坡口，然后渐缩到裙尖处。,Welding sequence,Especially note,When using the charts in
10、MSS SP-97 when the pipe wall schedule actually being used is heavier than listed in the chart you need to use the next higher chart dimensions.This is based on on Table 1 and note(a)where since our run pipe schedule is Sch 80(wall thickness=0.938)and not XS(wall thickness=0.500)you need to use the S
11、CH 160 class fittings and dimensions which means we need to usethe105mm dimension.Purchase and Inspection materials should know this principle.当用MSS SP-97 查支管道壁厚时，表中壁厚应该采用高一级的尺寸。例如：当我们知道主管壁厚是Sch 80，我们应该采用 SCH 160 class 的管台尺寸，见表。所以采购和检查时应知道这个道理。,Especially notes,Multiple outlet headers requiring all
12、full size openings are subject to distortion because of the large number of holes that have to be cut in close proximity to one another.To eliminate the possibility of distortion occurring when using weldolets in this type of installation we recommend that a strap be left in the center of the hole,b
13、y cutting out two half moon section(as shown in sketch).This strap acts as a support until after the weldolet has been installed and is then cut out 多管台的主管，需要开孔的话，由于相距 太近，开孔焊接易引起变形。为减少扭曲 变形我们推荐在孔中心预留一块不切割，先切割2个半月状，然后焊接。而中心 这一块可以防止焊接变形，等完全焊接 完成，用曲线据切除最后这一块。,Especially note,Weldolet welding often occu
14、rred issue:non-penetrationFor 4 and above,it could be welded at both side,even there is some difficulty with back gouging and back welding But for 3 and blower,it is not accessible with back gouging and back welding,the reason is 1)The torch size welding at back side is impossible access,and sometim
15、es the torch could not access the bevel well at some angle.2)The ID of weldolet and opening in run pipe has some deviation.3)The bevel curve of weldolet do not fit pipe well.Once found non penetration,need to cutting off the weldolet,reweld it from the run pipe to achieve penetration as could as pos
16、sible.12 mm non-penetration is acceptable.If more than 2mm non-penetration,back side need be welded.管台焊接常出现未焊透问题：大于等于4寸的管台，可以从内外两边焊，虽然有时 内部清根焊接有点困难 3寸及3寸以下管台，内部无法清根和焊接的原因如下 1）焊把尺寸大不易接近内部，有时角度不好而未焊透 2）管台内经合开孔又偏差 3）管台坡口曲线 与管道不匹配3寸及3寸以下管台一旦发现未焊透，需要割掉管台重新焊接或从主管道内部焊接。12 mm未焊透可接受，大于2mm未焊透背面要焊接,Site photoW
17、eldolet receive and inspection,Site photoAlignment and tack weld,Site photoWeldolet welding,Site photo,Every branch size bigger than 4 Must weld inside inside,Site photo,Site photo,Site photo,Site photo,Thank you,tell me more,airproducts,28,26、要使整个人生都过得舒适、愉快，这是不可能的，因为人类必须具备一种能应付逆境的态度。卢梭27、只有把抱怨环境的心情，化为上进的力量，才是成功的保证。罗曼罗兰28、知之者不如好之者，好之者不如乐之者。孔子29、勇猛、大胆和坚定的决心能够抵得上武器的精良。达芬奇30、意志是一个强壮的盲人，倚靠在明眼的跛子肩上。叔本华,谢谢！,
