CS vs LTCS Piping on piping class 2500#
CS vs LTCS Piping on piping class 2500#
(OP)
Hi all,
I am looking at a Petronas/Shell std for piping class 1500# and 2500#.
On small bore pipe, they specify ASTM A106 gradeB. (normal CS pipe, pipe thickness bellow 20 mm)
While for large bore pipe, they specify ASTM A333 grade 6 (Low Temp CS pipe, pipe thickness over 20 mm).
I am wondering why they specify that? Is it because of the PWHT requirements?
I am looking at a Petronas/Shell std for piping class 1500# and 2500#.
On small bore pipe, they specify ASTM A106 gradeB. (normal CS pipe, pipe thickness bellow 20 mm)
While for large bore pipe, they specify ASTM A333 grade 6 (Low Temp CS pipe, pipe thickness over 20 mm).
I am wondering why they specify that? Is it because of the PWHT requirements?





RE: CS vs LTCS Piping on piping class 2500#
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: CS vs LTCS Piping on piping class 2500#
And Shell does better engineering than the great majority of corps.
RE: CS vs LTCS Piping on piping class 2500#
I took a look at ASME B31.3, Chapter Material, "Fig. 323.2.2A Minimum Temperatures Without Impact Testing for Carbon Steel Materials".
When a material is thicker, it goes more britle?
Since my current understanding for impact test, is to know the "Ductile-Britle Transtition Temperature".
RE: CS vs LTCS Piping on piping class 2500#
When a material becomes thicker you have what is called plane strain condition or a tri-axial state of stress at a notch, defect or crack tip. This condition results in brittle fracture behavior. So, the thicker the material in the presence of a notch, or crack or defect the impact energy is lowered.