"W" Factor (Weld Joint)

[Mecha20]

Is it necessary to use the "W" factor in the calculating thickness for pressure piping? Trying to change a pipeline and would like to know the reason for considering this in the calculations.

Thanks.

 

[XL83NL]

1) You're not stating what design Code you're using, so I'm assuming its B31.3. Next time pls provide a little more detail so its easier to answer your question.
2) B31.3 is for piping, not pipelines.
3) What do you mean with 'change a pipeline'?
4) Do you mean the weld joint strength reduction factor W as per 302.3.5(e) of B31.3:2010?
5) Read 302.3.5(e), your answer is probably in there.