ASME sec IX 409.8 I&E range a Nonessential

[moe27]

AWS D1.1 has a +/- on the Amps and Volts as an essential variable but with ASME sec IX this is considered a Nonessential Variable.
MY questions are;
1) Why is this considered a Nonessential Variable?
2) If welding to an approved ASME sec IX WPS for a FCAW process and the welder is a little over or below the Volts and/or Amps range noted on the WPS, would the welder be welding out of bounds?
3) Could a third party surveyor witnessing the welding have a case for rejecting the welding if a welder is outside of the Nonessential Variables Parameters?

Thanking you,
Moe27

 

[weldstan]

Yes to questions 2 & 3; however, all the manufacturer/contractor need do to make the WPS OK is to revise the electrical parameters on its WPS.
The thickness range qualified, which mandates lowering or raising the electrical parameters depending on the thickness welded is one reason. Another is the power supply used. Voltage will vary during welding when using Constant Current power supplies and current will vary when welding with constant voltage power supplies especially when manual manipulation of the electrode/torch is performed.

 

[moe27]

Thank you weldstan,

Do you know if there is a +/- tolerance on the volts and amps under ASME similar to what AWS D1.1 has?

Moe27

 

[weldstan]

For standard arc welding processes, only on weld overlays (hard surfacing and corrosion resistant).