Pipeline Welding - Spatter

[Tuga29]

Hi to everyone, I'm having a problem with an approved WPS for welding a 18" 7.92mm pipeline.
WPS have SMAW for the root and FCAW-S for the Fill and Cap. The first x-rays showed too many spatter in the bottom, that makes the film impossible to interpret. I know that this is a issue already known when using the SMAW process and not having access to the inside to clean. But now we are having a very big problem... can someone give me some advices?

 

[gtaw]

If the problem is spatter inside the pipe from depositing the root bead, and if you are still depositing the root using SMAW, the problem is a change in how the root bead is being deposited. So, the question you need to answer is "What has changed when the welder deposits the root bead?"

Is the welder using the same electrode for the root pass?
Is the welder using the same parameters when depositing the root pass?
Has the configuration of the groove been changed?
Has the root opening or root face been increased or decreased?

If you were getting acceptable results before, but now you are getting unacceptable results, something has changed.

Since the root is deposited with SMAW, the root bbead should be the same as before if there are no changes. Next, ask the welder if the initial weld bead deposited with FCAW is "blasting" through the root bead. In other words, is the welder remelting and burning through the root bead deposited with SMAW?

Best regards - Al

 

[Tuga29]

We are just starting. Those were the first welds.

 

[DekDee]

See my response in the ASME section

 

[dik]

Could the amperage be set too high?

Dik

 

[Tuga29]

WPS specify 90-140A. They were using 120A more or less. The 4.0 rods are specified for 120-180A.
It's very strange that they can't do the work with the approved WPS.

 

[DekDee]

Excessive spatter is usually associated with high voltage and that is then related to excessive arc length.
Are they welding vertical up or down ?