PV plates rolling direction 1

[mancini]

I know that it is not usual, but may somebody inform if there is any restriction in ASME Sec VIII Div 1 or other Sections to manufacture a PV with the direction of the plate conformation executated during the fabrication, parallel to the plate rolling direction (as received from the mill)? In this case the axis of the shell (cylinder) will be parallel to the plate rolling direction.

In other words, the cylinder circumferential stress from the internal pressure will be perpendicular to the plate mill rolling direction and not parallel (as usual).

 

[jte]

mancini-

No restrictions to rolling direction that I'm aware of. As long as you keep your standard longitudinal and circumferential joints everyone should be happy. Anyone roll the plate diagonally, like a spiral welded pipe?

See

http://www.coking.com/Vendor/CBI.htm

for an application where the plates are formed with the axis of rotation perpendicular to that of the mill.

jt

 

[metengr]

No, there are no restrictions regarding rolling direction of plates in applicable ASME/ASTM Standards. The Specification that applies to ordering plate products is ASME SA-20 (if you want to review and understand all of the applicable requirements for ordering pressure vessel or boiler plate).

In particular for as-rolled plates, the tensile test specimen orientation that is required by paragraph, 11.2 states that the "longitudinal axis of the tensile specimen shall be transverse to the final rolling direction of the plate". Based on this statement it makes no difference how the plates are rolled as long as the rolling direction is established.

Tensile Testing for heat treated plates (after rolling) is also specified in ASME SA-20.

 

[arto]

Appendix 2-2(d)(2) refers to rolling up hubbed flanges from plate. Original plate surfaces parallel to flg axis, & PT/MT back & hub. Sounds like they're corncerned about laminations.

 

[mancini]

Thanks for all the answers.

Do you think, that if it is used the austenitic SS shell materials, is it recommended to request the plates raw materials with tension tests in the direction transverse of final rolling and also a bend test with the bending axis parallel to the plate rolling direction (as informed in SA 480)?

 

[SHG]

Please take a general point in this regard (not to austenitic S.S) that for rolled plates that the grains stretched in the rolling direction the mechanical properties in this direction -normally- is above the transverse direction. It means the tensile properties of the sample that the length is in rolling direction may be more than other direction and so on for charpy; and because of higher level of stress in circumference it's preferable to put the rolling direction in circumference (perpendicular of vessel axes).