Hi, If you application invloves welding of pipes (Where back chipping is not possible), there are two options for welding the root pass. 1. Use electrodes E 6010 or E 7010 (cellulosic Electrodes) or E 7016-1 for non critical lines (e.g., lines other than compressor suction / inlet lines). 2. Use STT (Surface Tension Transfer) Process for root pass, it is similar to GMAW short circuit transfer mode of metal transfer. You'll need to properly set the welding parameters to avoid any LOF, but once your welders are well trained, you can really see the productivity. Please note that some clients still have a restriction on using this process. If you application involves fabrication of pressure vessels, where you have enough access for back chipping the root pass, and you wish not to do so, then SAW is a good option. The joint preparation shall be such that the root face or the land should be long enough to prevent any burn though when welding the root pass, in addition to that you'll have to have tight butt joint (i.e.,) no root gap at all. After completion of one side, weld the other side (without back chipping) with SAW process, you parameters should be such that you have good cross penetration (engulfing the lan or root face) thus giving you a full penetration butt joint without the need for back chipping. Hope this helps. Regards, Praveen Alavandar --- On Thu, 6/30/11, rajeev arora <rajeevarora007@gmail.com> wrote:
-- Regards, Maulik H. Thakkar Larsen & Toubro, Hazira -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- Regards, Rajeev Arora 0066-854490697 0066-818706419 -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- Regards, Maulik H. Thakkar Larsen & Toubro, Hazira -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- Regards, Rajeev Arora 0066-854490697 0066-818706419 -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. |
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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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