16 Welding Pipe with GMAW and FCAW

When welding carbon steel pipe with GMAW or FCAW, the root bead is typically deposited with modified GMAW short circuiting transfer (GMAW-S) or traditional GMAW-S using 0.035” or 0.045” ER70S-6 electrode wire. The groove angle is in the range of 60˚ to 75˚ depending on wall thickness, with a 1/16” to 3/32” root face and a 3/32” to 1/8” root opening.

The intermediate and cover layers are deposited with pulsed spray transfer (GMAW-P) using 0.035” or 0.045” ER70S-6 or with gas shielded flux cored arc welding (FCAW-G) using 0.035” or 0.045” E71T-1 electrode wire. However, FCAW-G is typically used for in-house fabrication.

Overheating in the weld zone can be a problem because GMAW and FCAW are continuous wire processes. Therefore, it may be necessary to lower the current slightly on the cover layer to control the weld bead.