B31.3 interpretation

[aprincezk]

In ASME B31.3 for high pressure piping (ANSI class 2500 and above) it is strictly stated that API 5L pipe is only permitted in seamless condition. However, for any piping below ANSI class 2500 B31.3 merely states that 5L pipe "may require special consideration for welding qualification per ASME Boiler and Pressure Vessel code." I need to be perfectly clear on this and am having a hard time interpreting it.
Is it true if I am following B31.3 and I have an ANSI Class 1500 pipe with a seam, it is permissible for use so long as the seam is welded per BPV code?

 

[PAN]

I do not have experience to use seam pipe API 5L for flange class 1500.

What is the fluid service and design condition (pressure & temperature)?

 

[FIF99]

Yes but it must be noted that for wall thickness assessment a weld joint factor must be taken into account for API 5L Pipes.

See table 302.3.4

Regards,
FKE