Patent ID: 7170032

Claim:
In a process of buttwelding non-stainless steel metal workpieces having bevel joint preparations using GTAW welder using filler wire including: preparing the beveled workpieces with bevel joint areas having minimal land thicknesses at their root extremities; placing the prepared workpiece joint sections together with an open gap defining an open root area between their adjacent root extremities, the gap having a minimum dimension that avoids harmful compression stress between the workpieces due to weld shrinkage and a maximum dimension that avoids filler wire penetration of the gap; fusion welding the open root area of the adjacent workpieces with a root pass weld using a GTAW welder supplied with filler wire and a shield gas including 1 to 10% hydrogen and the balance inert gas; and then overlaying the root pass weld with at least one additional filler weld pass using a GTAW welder supplied with filler wire and hydrogen-free shield gas, the improvement wherein said open root pass is carried out in the substantial absence of moisture in the area undergoing welding using a shield gas delivery elastomer hose having a moisture permeability coefficient of 0 to 275.