ASME UCS-66 Assignment of SA387 Gr. 11

[kevlar49]

Hi,

the way I interpret UCS-66, SA387 Gr. 11 is assigned to the A curve for impact exemption. Some pressure vessel fabricators have been interpretting UCS-66 as saying that this should be on the 'B' curve. Are they right?

 

[SnTMan]

kevlar49, it is common practice in my area of the world (mid-USA) and class of work (Shell & Tube HX) to assign this material to curve B.

It is clear that if FG & N it is a curve B material, per note (b)(2). It is not so clear that any particular piece of plate is FG & N however. I don't have SA-387 handy at the moment to see if grain size is specified, however I believe it allows normalization.

Most often, the customer specifies -20 MDMT or lower so you impact test all of it anyway.

Regards,

Mike

 

[metengr]

kevlar49;
Unless SA 387 plate is specified as fine grained and normalized, it falls under Curve A category.