Performance differences SAW vs HFW

[rbradshaw2021]

Are there differences in quality/performance between an X70 HFW pipe and an X70 DSAW pipe? Other then the filler metal, if they are both rated for a min YS of 70,000PSI, why would one choose DSAW over HFW?

 

[PAN]

Fusion welding is different from pressure welding in principle. HFW pipes have inherent risk in my opinion.
However, this depends on your specific requirements/specifications and application in your case.

 

[rbradshaw2021]

My understanding was, previously, ERW pipe was manufactured using low frequency current, which in turn created lack of fusion concerns on the weld seam. HFW is a higher frequency, and to my understanding alleviates the seam bonding concerns. Pipes produced from electric welding techniques are cheaper to produce then SAW materials so why wouldn't someone want the EW pipe over SAW pipe. This is more just a general question trying to better understand the downside of EW materials.

 

[blacksmith37]

ERW welds are more likely to be messed up if not done by a "good" mill. Be sure the pipe and welds conform to API which means it is best to have a witness during manufacture . Make sure the whole weld is recrystallized , not just heated to lower temperature. The witness needs to look at the metallographic sample from each shift. I would avoid slit skelp ; that reduces the risk of inclusions in the fusion zone. It can be excellent depending on the mill .

 

[SJones]

For the same size and dimensions of PSL2 pipe that are within the manufacturing range of each mill, and with a qualified manufacturing procedure, using verified NDT equipment and procedures, the only difference will be price.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.