it is permissible to weld open butt joints without argon backing gas.

[Rene Alvarado]

In my personal opinion according to ASME IX, it is permissible to weld open butt joints without argon backing gas.

Welders Qualification:

Welders were qualified on groove joints of an inert gas backed pipe. The welding procedure used for both welders qualification as well as welding production welds is qualified with inert backing gas.

In accordance with Section IX QW-408.8 Essential Variable for Welders (QW-356 / QW-408.8 Gas / “Inert Gas Backing Removal”), welders are qualified to make production welds on groove joints with backup gas.

Reference: Essential variable for the welder: QW-408.8. The removal of inert backing gas. Except that requalification is not required when a one-sided welded butt joint is welded with a backing plate/ring or a double-sided welded butt joint or a fillet weld. This exception does not apply to metals from P-No. 51 through P-No. 53, P-No. 61 through P-No.62 and P-No.10I.

WPS-IAI-007 Rev. 2: The welding procedure has been qualified to weld P-No. 5A using an open butt joint design with argon backing gas. Per QW-408.5 (non-essential variable) argon backing gas can be deletion without re-qualifying the procedure since QW-408.5 covers the deletion or addition of backing gas and since this is a non-essential variable for applying procedural processes (in this case GTAW).

it is permissible to weld open butt joints without argon backing gas??

Regards