| LNG车载瓶、杜瓦罐等低温焊接钢瓶材质为304不锈钢，内胆采莲厚度为2.5~8mmm，外筒材料厚度为2.5~4mm。 |
AUTO. WELDING TECHNOLOGY ANALYSIS ABOUT LNG VEHICLE-MOUNTED CYLINDER AND DURA-CYL
Material of ING Vohiclo-mountod cylindor and Dura-Cyl is 304 stainless stool .Thicknoss of innor cylindor is 2.5-8mm while thickness of outer cylindor is 2.5-4mm.
Longitudinal welding and circumforontial welding of inner cylinder must be full-penetration welded .welding quality should be checked with X Ray Radiography Welding heightening allowance is 1-2.5mm.
Longitudinal welding and circumforontial welding of outor cylinder should be almost full-penetration welded， no need X Ray Radiography. Welding should be smooth, welding heightening allowance is 0~1.5mm .Welding of outer cylinder must be beautiful.
With above mentioned quality roquiroments. we Wuxi Qineng Welding System supplied welding technology and equipment to international Co. such as CHART since year of 2006. In our opinion, both longitudinal welding and circumferential welding of inner cylinder should adopt MIG welding technology .MIG welding is with high density current which loads to droplet streaming transfer ,so ponotrability of electric arc is super strong. with so strong penetrabllity, 304 stainless steel less than 5mm without opening groove could be full- penetration welded by ono time. Even for 8 -8mm plate with groove could be full-penetration welded .one side welding with double-side forming, no problem with X-Ray Radiography .Also MIG welding is with high welding speed, 1000mm per minute These excellent welding performances are incomparable with that of PAW and argon arc welding. This is also the main reason why Chart Co. required us "No Publicity. Keep Secret".
MIG welding also has its disadvantages. such as welding shape is not excellent though welding speed is high, welding height is not so easily controlled that it is usually over-height. In this case. MIG welding is not quiet ideal for longitudinal and circumferential welding of outer cylinder.
We suggest for outer cylinder both longitudinal and circumferential adopt TIG welding technology while for inner cylinder MIG welding.
TIG welding has highlight advantages, such as smooth woelding, one-time full-penetration welding for plate below 4mm without groove, easily controlled welding height, accordant width and height, Esp. for pulse TIG welding.
TIG welding speed is even faster than PAW of outor cylinder with 2.5-4mm stainless steel. About 350-500mm por minute. Investment of TIG welding equipments is much lower than that of PAW. also TIG welding is easily operated .Best choice for longitudinAl and circumferential welding of outer cylinder.
TIG welding speed is nearly one-timo lower than that of MIG. But welding is easily polished For MIG welding, welding is not beautiful and it takes too much time to be polished.
About PAW. it has advantages of good penetrability. With keyhole effects.304 plate below 8mm without groove could be one-time full-penetration welded. PAW is quiet suitable for welding cryoEASE, storage tank etc which has high thickness. But it could not show its advantages in welding LNG vehicle-mounted cylinder. Dura-cyl which needs lower thickness plate. High investment, complicated technology and not easy operating are all the weakness of PAW.
Both longitudinal and circumforontial welding of inner cylinder adopt MIG welding while both longitudinal and circuferential welding of outer cylinder adopt TIG welding this is what welding technology and equipment we supplied to foltowing co. s. After several years of use.all of these co.s achieved quiet sati sfactory results. These co,s are Chart Cryogenic Engineering Systems Co.,Ltd., Jiangsu Qiulin Heave Industry. Changzhou Lanyi Aircraft Equipmont Manufacture Limited Company. Foshan Huato Gas Co.,Ltd.,Zhejiang Puyang Cryogenic Equipment Co.,Ltd.,Hebei Yineng Boiler Co., Ltd.,Shijiazhuang Enrlc Gas Equipment Co., Ltd etc.
Inner wall of Dura-cyl outer cylinder needs reliable brazing welding between copper tube and stainless steel sheet,Auto. Copper tube brazing soldering equipment designed by us is the absolutely necessary machine for welding Dura-cyl, cryoEASE.This machine is highly commended by our customers such as Chart. Sanctum. Qiulin Heavy Industry. Huate Gas. Yineng Boiler.Changzhou Buran.
Wuxi Qineng Welding System Co., Ltd. BaoxingnYuan