ASME B31.3 Category M service and welded pipe 1

[GD_P]

Hello,

For 25 NB category M service line with 70 bar pressure, whether welded pipe/ERW pipe can be used for this case as per b31.3?

I don't find any such restriction for not using welded pipe.

Contradictorily, ASME VIII Div do not allow ERW pipes for lethal fluids.

I am confused whether or not to use welded pipe, as the pressure is quite high as well?

GD_P

 

[XL83NL]

What is 25 NB? 25 inch nominal bore?
70 bar may or may not be high, depending on one's definition of what's high. To me it's not high.
B31.3 has additional requirements for Cat. M Fluid Service (note the addition of the word Fluid), see Chap. VIII.
As far as I can tell, there's nothing in Chapter VIII prohibiting welded pipe, apart from that outlined in M305.2.2.

 

[GD_P]

It is DN 25 pipe.

Yes, you are right its Cat. M Fluid Service not cat. M service.

Thanks for the information.

GD_P